Part One (Short version) Part Two Part Three Part Four Part Five

This is the long version of Aquinas' Fifteen "Smoking Guns." If you are reading this page, I shall assume that you are either a scholar, or a keen student of Aquinas. Before reading this page, I would urge you to read the first part of the short version of Aquinas' Fifteen "Smoking Guns," down to the end of Section One, which lists all fifteen "Smoking Guns" in summary form. In this post, the Fifteen "Smoking Guns" will be listed with exhaustive documentation from the writings of Aquinas, which readers will be able to check by clicking on the hyper-links. Readers will also be able to navigate freely from one point to another.

The following fifteen statements (or theses) are either explicitly found in the writings of St. Thomas Aquinas, or can be deduced immediately from statements he makes in his writings. Quotations are provided below, and hyper-linked citations are included. Each of these statements is a "Smoking Gun," which refutes Professor Tkacz's ridiculous claim that Intelligent Design is "inconsistent with the Catholic intellectual tradition," while Darwinian evolution, properly understood, is perfectly compatible with that tradition. Professor Tkacz claims to speak as a "modern Thomist." However, I shall endeavor to demonstrate that his own philosophical master, St. Thomas Aquinas, held a contrary view to that of Professor Tkacz, on each of the fifteen points listed below.

AQUINAS' FIFTEEN SMOKING GUNS, WITH SUPPORTING QUOTES PROVIDED IN FULL, AND IN CONTEXT

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Noel Coypel, "The Resurrection of Christ," 1700.
According to Aquinas, events requiring a supernatural cause are the best possible manifestation of God's agency in the world. However, Professor Tkacz derides arguments for God's existence that appeal to supernatural effects as "God of the gaps" arguments.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
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SHORT Version of "Smoking Gun" Number 1

"SMOKING GUN" Number 1:

PHYSICAL EFFECTS REQUIRING A SUPERNATURAL CAUSE ARE THE BEST POSSIBLE WAY OF DEMONSTRATING GOD'S POWER AND FREE AGENCY.

According to Aquinas, God's existence and agency can be known from the things that He has made (Romans 1:20). Indeed, he put forward no less than five arguments for God's existence in his Summa Theologica I, q. 2, art. 3 (Whether God exists). However, Aquinas believed that events requiring a supernatural cause are the best possible manifestation of God's agency in the world.

Aquinas taught that special effects which can only have a supernatural cause, are an excellent way of demonstrating God's agency, especially to skeptics. Events occurring outside the order of nature manifest God's agency in the best possible way, for they manifest God's power and voluntary agency in a way that is evident to everyone.

My conclusion: St. Thomas would have therefore highly commended "God of the gaps" arguments, so long as they convincingly demonstrate that some effect which we perceive in the world around us is outside the order of nature. I shall discuss what kind of evidence would have convinced Aquinas in "Smoking Gun" number 12 below.

Where Aquinas says this:

In his Summa Contra Gentiles Book III chapter 99 (paragraph 9) (That God Can Work Apart From The Order Implanted In Things, By Producing Effects Without Proximate Causes):

[9] Now, if someone says that, since God did implant this order in things, the production in things of an effect independently of its proper causes, and apart from the order established by Him, could not be done without a change in this order, this objection can be refuted by the very nature of things. For the order imposed on things by God is based on what usually occurs, in most cases, in things, but not on what is always so. In fact, many natural causes produce their effects in the same way, but not always. Sometimes, indeed, though rarely, an event occurs in a different way, either due to a defect in the power of an agent, or to the unsuitable condition of the matter, or to an agent with greater strength-as when nature gives rise to a sixth finger on a man. But the order of providence does not fail, or suffer change, because of such an event. Indeed, the very fact that the natural order, which is based on things that happen in most cases, does fail at times is subject to divine providence. So, if by means of a created power it can happen that the natural order is changed from what is usually so to what occurs rarely - without any change of divine providence - then it is more certain that divine power can sometimes produce an effect, without prejudice to its providence, apart from the order implanted in natural things by God. In fact, He does this at times to manifest His power. For it can be manifested in no better way, that the whole of nature is subject to the divine will, than by the fact that sometimes He does something outside the order of nature. Indeed, this makes it evident that the order of things has proceeded from Him, not by natural necessity, but by free will.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz regards the contingency of the natural world as the best evidence for God's existence. Aquinas, in his Third Way, argued that God's existence could be demonstrated from the radical contingency of Nature, in his Summa Theologica I, q. 2, art. 3 (Whether God exists) and Summa Contra Gentiles Book I, chapter 13, paragraph 25 (Arguments in proof of the existence of God). However, he regarded events occurring outside the order of nature as the best possible manifestations of God's power and voluntary agency; whereas Tkacz derides appeals to supernatural effects as "God of the gaps" arguments, as the following quotes show:

In his original talk given to the Gonzaga Socratic Club, Professor Tkacz said:

Now, a Thomist might agree with Behe's epistemological claim that no current or foreseeable future attempt at explanation for certain biological complexities is satisfactory. Yet, a Thomist will reject Behe's ontological claim that no such explanation can ever be given in terms of the operation of nature. This ontological claim depends on a "god of the gaps" understanding of divine agency and such an understanding of God's action is cosmogonically fallacious.

In his article for the journal This Rock, Professor Tkacz discusses the question of what constitutes legitimate evidence for God's existence. Tkacz makes it abundantly clear that he regards any appeals to effects in the cosmos which require a Supernatural Cause as "God-of-the-gaps" arguments, which he considers to be at odds with the authentic tradition of the Church:

[T]he evidence for God's Creation of the natural universe is the known fact - a fact that we know on the basis of our scientific research - that natural things are intelligible... This ultimate source for the being and intelligibility of nature cannot be yet another natural thing. It must be something outside of nature that has the power to produce the totality of nature and does not itself require a cause...

Insofar as ID theory represents a "god of the gaps" view, then it is inconsistent with the Catholic intellectual tradition.

On the contrary, Professor: what would be truly "inconsistent with the Catholic intellectual tradition" is a refusal to even examine newly discovered physical effects occurring in Nature, which may require a supernatural cause in order to explain them. Whatever their merits, Aquinas would say that these effects at least warrant honest investigation.

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The Earth, seen from Apollo 17.
According to Professor Tkacz, Nature is maintained in being by God, but God does not intervene in Nature.
Aquinas disagreed: he held that God could produce effects in creatures directly, without using secondary causes, whenever He wished.

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SHORT Version of "Smoking Gun" Number 2

"SMOKING GUN" Number 2:

GOD CAN (AND SOMETIMES DOES) PRODUCE EFFECTS IN NATURE, WITHOUT USING NATURAL AGENTS.

According to Aquinas, God can produce effects in Nature, without using natural agents.

Aquinas taught that God is certainly capable of producing effects in creatures immediately, without using secondary causes, and moreover, it is perfectly appropriate for Him to do so, if He so wishes. Nature is not autonomous, in either its being or its operations.

Where Aquinas says this:

(1) In his Summa Theologica I, q. 105 art. 1 (Whether God can immediately move the matter to the form?) Aquinas considers several objections, and then responds:

On the contrary, It is written (Genesis 2:7): "God formed man of the slime of the earth."

I answer that, God can move matter immediately to form; because whatever is in passive potentiality can be reduced to act by the active power which extends over that potentiality. Therefore, since the Divine power extends over matter, as produced by God, it can be reduced to act by the Divine power: and this is what is meant by matter being moved to a form; for a form is nothing else but the act of matter.

(2) In his Summa Theologica I, q. 105 art. 2 (Whether God can move a body immediately?)

I answer that, It is erroneous to say that God cannot Himself produce all the determinate effects which are produced by any created cause. Wherefore, since bodies are moved immediately by created causes, we cannot possibly doubt that God can move immediately any bodies whatever. This indeed follows from what is above stated (art. 1)... Therefore, as God can imprint form immediately in matter, it follows that He can move any body whatever in respect of any movement whatever.

(3) In his Summa Contra Gentiles Book III chapter 99 (paragraphs 1, 2 and 9) (That God Can Work Apart From The Order Implanted In Things, By Producing Effects Without Proximate Causes):

[1] It remains to show now that He can act apart from the order implanted by Him in things.

[2] Indeed, there is an order divinely instituted in things to the effect that lower things are moved through higher ones by God, as we said above. Now, God can act apart from this order; for instance, He may Himself produce an effect in lower things, with nothing being done, in this case, by a higher agent. In fact, there is a difference on this point between an agent that acts by natural necessity and one that acts according to will; an effect cannot result from one that acts by natural necessity except according to the mode of the active power - so, an agent that has very great power cannot directly produce a small effect, but it produces an effect in proportion to its power. But, in this effect, there is sometimes less power than in the cause, and so, by means of many intermediaries, there finally comes to be a small effect from the highest cause. However, the situation is not the same in the case of an agent working through will. For one who acts through will is able at once to produce without an intermediary any effect that does not exceed its power. For instance, the very perfect artisan can produce any kind of work that the less perfect artisan could make. Now, God operates through will, and not through natural necessity, as we showed above. Therefore, He can produce immediately, without special causes, the smaller effects that are produced by lower causes....

[9] Now, if someone says that, since God did implant this order in things, the production in things of an effect independently of its proper causes, and apart from the order established by Him, could not be done without a change in this order, this objection can be refuted by the very nature of things. For the order imposed on things by God is based on what usually occurs, in most cases, in things, but not on what is always so. In fact, many natural causes produce their effects in the same way, but not always.... But the order of providence does not fail, or suffer change, because of such an event. Indeed, the very fact that the natural order, which is based on things that happen in most cases, does fail at times is subject to divine providence. So, if by means of a created power it can happen that the natural order is changed from what is usually so to what occurs rarely - without any change of divine providence - then it is more certain that divine power can sometimes produce an effect, without prejudice to its providence, apart from the order implanted in natural things by God. In fact, He does this at times to manifest His power. For it can be manifested in no better way, that the whole of nature is subject to the divine will, than by the fact that sometimes He does something outside the order of nature. Indeed, this makes it evident that the order of things has proceeded from Him, not by natural necessity, but by free will.

(4) In his Quaestiones Disputatae de Potentia Dei (Disputed Questions on the Power of God) Q. VI article I, Aquinas asks: can God do anything in creatures that is beyond Nature, against Nature, or contrary to the course of Nature? Here is how he responds:

I answer that, without any doubt God can work in creatures independently of created causes, just as he works in all created causes, as shown elsewhere: and by working independently of created causes he can produce the same effects and in the same order as he produces them by their means: or even other effects and in a different order: so that he is able to do something contrary to the common and customary course of nature.

(5) Finally, in his Summa Contra Gentiles Book III, chapter 100, paragraphs 6 and 7, Aquinas argues that nothing God does to Nature can be contrary to Nature, simply because He is Nature's Creator:

[6] Furthermore, all creatures are related to God as art products are to an artist, as is clear from the foregoing. Consequently, the whole of nature is like an artifact of the divine artistic mind. But it is not contrary to the essential character of an artist if he should work in a different way on his product, even after he has given it its first form. Neither, then, is it against nature if God does something to natural things in a different way from that to which the course of nature is accustomed.

[7] Hence, Augustine says: "God, the creator and founder of all natures, does nothing contrary to nature; for what the source of all measure, number and order in nature does, is natural to each thing" [Contra Faustum, XXVI, 3].

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz maintains that Nature is autonomous in "her" operations, and that God does not "intervene" in Nature. God maintains things in being, but they operate by themselves, in the way God intended them to.

In his original talk given to the Gonzaga Socratic Club, Professor Tkacz said:

[M]odern Thomists distinguish between the existence of natural beings and their operations. God causes natural beings to exist in such a way that they are the real causes of their own operations...

Now, if this distinction between the being of something and its operation is correct, then nature and her operations are autonomous in the sense that nature operates according to the way she is, not because something outside of her is acting on her. God does not act on nature the way a human being might act on an artifact to change it. Rather, God causes natural beings to be in such a way that they work the way they do.

In his article for the journal This Rock, Professor Tkacz wrote:

God does not intervene into nature nor does he adjust or "fix up" natural things. God is the divine reality without which no other reality could exist. Thus, the evidence of nature's ultimate dependency on God as Creator cannot be the absence of a natural causal explanation for some particular natural structure. Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature.

"God does not intervene into nature nor does he adjust or 'fix up' natural things." For "any given feature of living organisms," "there must exist some explanatory cause in nature." I think that's pretty clear language.

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Russian Icon. "The Raising of Lazarus." 15th century. The Russian Museum, St. Petersburg, Russia.
According to Aquinas, the production of the body of the first human being (Adam) was a change that surpassed the power of Nature, and must have been caused by the power of God alone. Indeed, Aquinas even believed that the production of Adam's body was no less marvelous than the raising of a dead body to life.

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SHORT Version of "Smoking Gun" Number 3

"SMOKING GUN" Number 3:

SOME PHYSICAL CHANGES ARE BEYOND THE POWER OF NATURE TO BRING ABOUT: THEY CAN ONLY BE PRODUCED BY GOD.

According to Aquinas, some changes occurring in Nature require a supernaturalthey can only be brought about by God.

Aquinas taught that some physical changes are beyond the power of nature to bring about. These changes cannot have a naturalistic explanation. They must therefore be produced by the power of God alone. Examples include the raising of a dead body, the production of the first human body from inanimate matter and the production of the first animals, according to their various kinds. (Following Aristotle, Aquinas also mistakenly believed that some animals which were generated spontaneously, without "seed," from dead and decaying matter, and that God need not have produced these animals in the beginning.)

Where Aquinas says this:

In his Summa Theologica I, q. 91, article 2, reply to objection 3, Aquinas addresses the question of whether the human body of Adam was immediately produced by God:

Reply to Objection 3. The movement of the heavens causes natural changes; but not changes that surpass the order of nature, and are caused by the Divine Power alone, as for the dead to be raised to life, or the blind to see: like to which also is the making of man from the slime of the earth.

Summa Theologica I, q. 92 art. 4 (Whether the woman was formed immediately by God?)

I answer that, As was said above (2, ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man.

Note: Aquinas' reference to the "semen" of woman may perplex some readers. However, Aquinas used the term "seed" and "semen" in a much broader sense than we do today, as the following passage in his Summa Theologica, I, q. 115 art. 2, Reply to Objection 3 makes clear:

Reply to Objection 3. The seed of the male is the active principle in the generation of an animal. But that can be called seed also which the female contributes as the passive principle. And thus the word "seed" covers both active and passive principles.

Finally, in his Summa Contra Gentiles Book II chapter 43, paragraph 6 (That the distinction of things is not caused by some secondary agent introducing diverse forms into matter), Aquinas argues that the forms of the very first animals must have been produced immediately by God, according to their kind, for those animals which are "generated only from seed":

[6] ... There are, however, many sensible forms which cannot be produced by the motion of the heaven except through the intermediate agency of certain determinate principles pre-supposed to their production; certain animals, for example, are generated only from seed. Therefore, the primary establishment of these forms, for producing which the motion of the heaven does not suffice without their pre-existence in the species, must of necessity proceed from the Creator alone.

Aquinas also mistakenly believed that some animals could be generated spontaneously from dead and decaying matter. He thought that these animals need not have been produced by God in the beginning. Aquinas' belief in spontaneous generation was heavily influenced by the biology in Aristotle's History of Animals Book V, part 1 (see paragraph 3):

So with animals, some spring from parent animals according to their kind, whilst others grow spontaneously and not from kindred stock; and of these instances of spontaneous generation some come from putrefying earth or vegetable matter, as is the case with a number of insects, while others are spontaneously generated in the inside of animals out of the secretions of their several organs.

As we have seen (Summa Theologica, I, q. 115 art. 2, Reply to Objection 3), for Aquinas, the term "seed" can cover both the male's and the female's contributions to their offspring; Aquinas believed these contributions to be active and passive, respectively. Thus Aquinas' statement above that certain animals "are generated only from seed" does not refer exclusively to those animals that can only reproduce sexually. It refers to those animals that have either one parent (as in parthenogenesis), or two parents (as in sexual reproduction). (Scientists now know that most animals can reproduce in both ways.) For Aquinas, animals that are not "generated from seed" are therefore those lower ("imperfect") animals which he mistakenly believed were spontaneously generated from dead or decaying matter.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz insists that God does not "intervene" in Nature, or "adjust" it in any fashion. Hence there cannot be any living organisms in Nature that could only have been produced by God's supernatural agency. All living things must have a natural origin.

In his article for the journal This Rock, Professor Tkacz wrote:

Unlike the causes at work within nature, God's act of Creation is a completely non-temporal and non-progressive reality. God does not intervene into nature nor does he adjust or "fix up" natural things. God is the divine reality without which no other reality could exist. Thus, the evidence of nature's ultimate dependency on God as Creator cannot be the absence of a natural causal explanation for some particular natural structure. Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature.

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The Pleiades, an open cluster of stars in the constellation of Taurus. Aquinas believed that Nature is an open system: angels have to continually move the stars and other heavenly bodies, in order to regulate biological processes taking place on Earth. Without angels moving the celestial bodies, the generation of life on Earth would grind to a halt.
Professor Tkacz, on the other hand, maintains that Nature is autonomous in its operations, requiring no input from outside. The universe is kept in being by God, but in its day-to-day operations, it is a closed system.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
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SHORT Version of "Smoking Gun" Number 4

"SMOKING GUN" Number 4:

THE PHYSICAL UNIVERSE IS AN OPEN SYSTEM: WITHOUT ANGELS ACTING ON IT CONTINUALLY, THE GENERATION OF NEW LIFE ON EARTH WOULD COME TO A COMPLETE STOP.

According to Aquinas, the physical universe ("the realm of corporeal nature") is not a closed system but an open one: in fact, the universe needs bodiless intelligent agents (i.e. angels) to be acting on it continually, or otherwise all natural processes would grind to a halt. Angels move the heavenly bodies not by "pushing" them, but simply by applying the power of their intellects to them. Aquinas believed that the heavenly bodies played a crucial role in the regulation of natural processes on Earth - in particular, the generation of new organisms. In the Middle Ages, the heavenly bodies were believed to play a vital role in reproduction, even for the higher animals (or "perfect animals," as Aquinas called them); the heavenly bodies were also believed to be able to generate the lower animals, simply by acting on dead or decaying matter.

Aquinas taught that just as a craftsman works through his tools, angels use the heavenly bodies as their instruments, to regulate the generation of living things on Earth. Without the angels continually moving the heavenly bodies, animals and plants would be unable to reproduce themselves naturally; and even the spontaneous generation of living organisms from dead and decaying matter (which Aquinas and his contemporaries believed in) could not take place.

Where Aquinas says this:

The claims listed above can be expressed in the form of an eight-step logical argument:

(a) According to Aquinas, the heavenly bodies are distinguished from other bodies by being incorruptible. The only change which heavenly bodies undergo is a change of position, when they move from one place to another.

Summa Contra Gentiles Book II, chapter 92 (Concerning the great number of separate substances):

[7] The order of the universe, furthermore, seems to require that whatever is nobler among things should exceed in quantity or number the less noble; since the latter seem to exist for the sake of the former. That is why the more noble things, as existing for their own sake, should be as numerous as possible. Thus we see that the incorruptible, or heavenly, bodies so far exceed the corruptible, or element-composed, bodies, that the latter are in number practically negligible by comparison. However, just as the heavenly bodies are nobler than those composed of elements - the incorruptible than the corruptible - so intellectual substances are superior to all bodies, as the immovable and immaterial to the movable and material. The number of separate intellectual substances, therefore, surpasses that of the whole multitude of material things.

Summa Contra Gentiles Book II, chapter 16 (That God brought things into being from nothing):

... the heavenly bodies acquire new positions, but no new existences, as the lower bodies do.

Summa Contra Gentiles Book III, chapter 82 (That lower bodies are ruled by God through celestial bodies):

[4] Moreover, it was shown above that all things are ruled through intellectual substances. But celestial bodies are more like intellectual substances than are other bodies because the former are incorruptible. They are also nearer to them, inasmuch as they are moved immediately by them, as we showed above. Therefore, the lower bodies are ruled by them.

(b) All physical processes - whether they be quantitative or qualitative changes, or transformations of one thing into another - are explicable in terms of the movements taking place in bodies, as they are being changed. Additionally, all movements taking place in corruptible bodies are in turn governed by the movements of the incorruptible heavenly bodies. Hence, all physical processes are ultimately governed by the movements of the heavenly bodies.

Summa Contra Gentiles Book II, chapter 43 (That the distinction of things is not caused by some secondary agent introducing diverse forms into matter):

[6] Then, too, motion in respect of form is naturally posterior to local motion, since the former is the act of that which is more imperfect, as Aristotle proves [Physics, VIII, 7]. Now, in the natural order, things posterior are caused by things prior. Therefore, motion with respect to form is caused by local motion. The first local motion, however, is that of the heaven. Hence, all motion toward form is brought about through the mediation of the heavenly motion.

Summa Contra Gentiles Book III, chapter 82 (That lower bodies are ruled by God through celestial bodies):

[5] Furthermore, the first source of motion must be something immutable. So, the things that are nearest to immutability should be movers of the rest. But celestial bodies approach more closely to the immutability of the first source than do lower bodies, for they are not moved except by one kind of motion, namely, local motion; while other bodies are moved by all the species of motion. Therefore, the celestial bodies move and govern the lower bodies.

[7] Besides, as the absolutely immobile is to unqualified motion, so is the immobile, that is qualified by a given motion, related to that motion. Now, that which is absolutely immobile is the source of all motion, as we proved above. So, what is immobile in regard to alteration is the source of all alteration. Now, the celestial bodies, alone among bodily things, are inalterable; their condition shows this, for it is always the same. So, the celestial body is the cause of all alteration in things that are changed by alteration. Now, in these lower bodies alteration is the source of all motion, for through alteration a thing achieves increase and generation, whereas the agent of generation is a self-mover in the local motion of heavy and light things. Therefore, the heavens must be the cause of all motion in these lower bodies.

(c) The heavenly bodies, in their turn, need to be moved by intelligent beings.

Summa Contra Gentiles Book III, chapter 23 (That the motion of the heavens comes from an intellectual principle):

[3] Again, everything that is moved must be moved by another being, as we proved earlier. Therefore, a celestial body is moved by something else. So, this other thing is either completely separated from it, or is united with it in the sense that the composite of the celestial body and the mover may be said to move itself, in so far as one of its parts is the mover and another part is the thing moved. Now, if it works this way, since everything that moves itself is alive and animated, it would follow that the heavens are animated, and by no other soul than an intellectual one: not by a nutritive soul, for generation and corruption are not within its power; nor by a sensitive soul, for a celestial body has no diversity of organs. The conclusion is, then, that it is moved by an intellective soul. - On the other hand, if it is moved by an extrinsic mover, this latter will be either corporeal or incorporeal. Now, if it is corporeal, it will not move unless it is moved, for no body moves unless it is moved, as was evident previously. Therefore, it will also have to be moved by another. And since there should be no process to infinity in the order of bodies, we will have to come to an incorporeal first mover. Now, that which is utterly separate from body must be intellectual, as is evident from earlier considerations. Therefore, the motion of the heavens, that is of the first body, comes from an intellectual substance.

[8]... And so, the motion of a celestial body, as far as its active principle is concerned, is not natural, but voluntary and intellectual; however, in relation to its passive principle, the motion is natural, for a celestial body has a natural aptitude for such motion.

[10] That the motion of the heavens is voluntary according to its active principle is not repugnant to the unity and uniformity of celestial motion because of the fact that the will is open to a plurality of actions and is not determined to one of them. In fact, just as a nature is determined to one objective by its power, so is the will determined to one objective by its wisdom, whereby the will is infallibly directed to one end.

[12] Nor does it make any difference, as far as our present purpose is concerned, whether a heavenly body is moved by a conjoined intellectual substance which is its soul, or by a separate substance; nor whether each celestial body is moved immediately by God, or whether none is so moved, because all are moved through intermediary, created, intellectual substances; nor whether the first body alone is immediately moved by God, and the others through the mediation of created substances - provided it is granted that celestial motion comes from intellectual substance.

(d) The intelligent beings which move the heavenly bodies are both incorporeal and immaterial. These intelligent beings, which we call angels, have no bodies of their own, and they do not contain any kind of matter.

Summa Contra Gentiles Book II, chapter 91 (That there are some intellectual substances which are not united to bodies):

[1] Now, the preceding considerations enable us to show that some intellectual substances exist in complete separation from bodies.

[9] Again, in Metaphysics XI [8] Aristotle reasons as follows. Movement that is continuous, regular, and in its own nature unfailing must be derived from a mover which is not moved, either through itself or by accident, as was proved in Book I of this work. Moreover, a plurality of movements must proceed from a plurality of movers. The movement of the heaven, however, is continuous, regular, and in its nature unfailing. And besides the first movement, there are many such movements in the heaven, as the studies of the astronomers show. Hence, there must be several movers which are not moved, either through themselves or by accident. But, as we proved in that same Book, no body moves unless it is itself moved; and an incorporeal mover united to a body is moved accidentally in keeping with the movement of the body, as we see in the case of the soul. Hence, there must be a number of movers which neither are bodies nor are united to bodies. Now, the heavenly movements proceed from an intellect, as we have also shown. We therefore conclude to the existence of a plurality of intellectual substances that are not united to bodies.

[10] With this conclusion Dionysius is in agreement, when, speaking of the angels, he says that "they are understood to be immaterial and incorporeal" [De div. nom. IV].

Summa Theologica I, q. 50, article 1 (Whether an angel is altogether incorporeal?):

I answer that, There must be some incorporeal creatures. For what is principally intended by God in creatures is good, and this consists in assimilation to God Himself. And the perfect assimilation of an effect to a cause is accomplished when the effect imitates the cause according to that whereby the cause produces the effect; as heat makes heat. Now, God produces the creature by His intellect and will (14, 8; 19, 4). Hence the perfection of the universe requires that there should be intellectual creatures. Now intelligence cannot be the action of a body, nor of any corporeal faculty; for every body is limited to "here" and "now." Hence the perfection of the universe requires the existence of an incorporeal creature.

Summa Theologica I, q. 51, article 1 (Whether the angels have bodies naturally united to them?):

I answer that, The angels have not bodies naturally united to them. For whatever belongs to any nature as an accident is not found universally in that nature; thus, for instance, to have wings, because it is not of the essence of an animal, does not belong to every animal. Now since to understand is not the act of a body, nor of any corporeal energy, as will be shown later (75, 2), it follows that to have a body united to it is not of the nature of an intellectual substance, as such; but it is accidental to some intellectual substance on account of something else. Even so it belongs to the human soul to be united to a body, because it is imperfect and exists potentially in the genus of intellectual substances, not having the fulness of knowledge in its own nature, but acquiring it from sensible things through the bodily senses, as will be explained later on (84, 6; 89, 1). Now whenever we find something imperfect in any genus we must presuppose something perfect in that genus. Therefore in the intellectual nature there are some perfectly intellectual substances, which do not need to acquire knowledge from sensible things. Consequently not all intellectual substances are united to bodies; but some are quite separated from bodies, and these we call angels.

Summa Theologica I, q. 50, article 2 (Whether an angel is composed of matter and form?):

It is, further, impossible for an intellectual substance to have any kind of matter. For the operation belonging to anything is according to the mode of its substance. Now to understand is an altogether immaterial operation, as appears from its object, whence any act receives its species and nature. For a thing is understood according to its degree of immateriality; because forms that exist in matter are individual forms which the intellect cannot apprehend as such. Hence it must be that every intellectual substance is altogether immaterial.

(e) Angels do not move the heavenly bodies by pushing them, but by applying the force of their intellects. The angels move the heavenly bodies as their instruments, just as a craftsman works through his tools.

Summa Contra Gentiles Book II, chapter 100 (That Separate Substances Know Singulars):

[5] Moreover, if, as the philosophers say, the heavenly bodies are moved by the separate substances, then, since separate substances act and move by their intellect, they must know the movable thing which they move; and this is some particular entity, for universals are immovable. The new places, also, which result from movement are certain singular realities that cannot be unknown to the substance which exercises movement by its intellect. Therefore, it must be said that separate substances know singulars belonging to these material things.

Summa Contra Gentiles Book II, chapter 99 (That Separate Substances Know Material Things):

[4] Also, if the separate substances move the heavenly bodies, as the philosophers say, then whatever results from the movement of the heavenly bodies is attributed to those bodies as instruments, since they move in being moved, but is ascribed to the separate substances which move them, as principal agents. Now, separate substances act and move by their intellect. Hence, they are actually causing whatever is effected by the movement of the heavenly bodies, even as the craftsman works through his tools. Therefore, the forms of things generated and corrupted enjoy intelligible being in the separate substances. And that is why Boethius, in his book On the Trinity [II], says that from forms that are without matter came the forms that are in matter. Separate substances, then, know not only separate substances, but also the species of material things. For, if they know the species of generable and corruptible bodies, as the species of their proper effects, much more do they know the species of the heavenly bodies, as being the species of their proper instruments.

(f) Angels move the heavenly bodies in order to regulate the movements of earthly bodies that undergo generation and corruption. Specifically, the angels move the heavenly bodies in order to regulate the generation of living things on Earth. If the angels didn't continually move the heavenly bodies, all generation of new life on Earth - whether it be spontaneous generation or organisms reproducing after their own kind - would grind to a halt.

Summa Contra Gentiles Book II, chapter 99 (That Separate Substances Know Material Things):

[4] Also, if the separate substances move the heavenly bodies, as the philosophers say, then whatever results from the movement of the heavenly bodies is attributed to those bodies as instruments, since they move in being moved, but is ascribed to the separate substances which move them, as principal agents. Now, separate substances act and move by their intellect. Hence, they are actually causing whatever is effected by the movement of the heavenly bodies, even as the craftsman works through his tools. Therefore, the forms of things generated and corrupted enjoy intelligible being in the separate substances. And that is why Boethius, in his book On the Trinity [II], says that from forms that are without matter came the forms that are in matter. Separate substances, then, know not only separate substances, but also the species of material things. For, if they know the species of generable and corruptible bodies, as the species of their proper effects, much more do they know the species of the heavenly bodies, as being the species of their proper instruments.

Summa Contra Gentiles Book III, chapter 22 (How things are ordered to their ends in various ways):

[5] In regard to the way which involves movers that actively move, the end of their motion is to attain the divine likeness by being the causes of others. Now, they are the causes of others by the fact that they cause generation and corruption and other changes in these lower things. So, the motions of the celestial bodies, as actively moving, are ordered to the generation and corruption which take place in these lower bodies. - Nor is it unfitting that celestial bodies should move for the sake of the generation and corruption of these lower things, even though lower bodies are of less value than celestial bodies, while, of course, the end should be more important than what is for the sake of the end.

(g) The whole biological process of generation is ordered towards man: the generation of plants benefits animals, whose generation benefits human beings. Hence the ultimate reason why the angels move the heavenly bodies is for the benefit of human beings.

Summa Contra Gentiles Book III, chapter 22 (How things are ordered to their ends in various ways):

[5] In regard to the way which involves movers that actively move, the end of their motion is to attain the divine likeness by being the causes of others. Now, they are the causes of others by the fact that they cause generation and corruption and other changes in these lower things. So, the motions of the celestial bodies, as actively moving, are ordered to the generation and corruption which take place in these lower bodies. - Nor is it unfitting that celestial bodies should move for the sake of the generation and corruption of these lower things, even though lower bodies are of less value than celestial bodies, while, of course, the end should be more important than what is for the sake of the end.

Indeed, the generating agent acts for the sake of the form of the product of generation, yet this product is not more valuable than the agent; rather, in the case of univocal agents it is of the same species as the agent. In fact, the generating agent intends as its ultimate end, not the form of the product generated, which is the end of the process of generation, but the likeness of divine being in the perpetuation of the species and in the diffusion of its goodness, through the act of handing on its specific form to others, and of being the cause of others. Similarly, then, celestial bodies, although they are of greater value than lower bodies, tend toward the generation of these latter, and through their motions to the actual eduction of the forms of the products of generation, not as an ultimate end but as thereby intending the divine likeness as an ultimate end, inasmuch as they exist as the causes of other things.

[7]... So, elements exist for the sake of mixed bodies; these latter exist for the sake of living bodies, among which plants exist for animals, and animals for men. Therefore, man is the end of the whole order of generation.

[9] So, if the motion of the heavens is ordered to generation, and if the whole of generation is ordered to man as a last end within this genus, it is clear that the end of celestial motion is ordered to man, as to an ultimate end in the genus of generable and mobile beings.

(h) However, the angels do not have unlimited power over objects in the physical universe. Angels are only able to influence events in the cosmos by moving the heavenly bodies. Hence, if there are any kinds of physical forms which cannot be generated by the movement of the heavenly bodies alone, then the angels will be incapable of generating these kinds of forms. Moreover, the first forms of these kinds could only have been produced by God.

In his Summa Theologica I, q. 65 art. 4, Aquinas asserts that "the corporeal forms that bodies had when first produced came immediately from God, whose bidding alone matter obeys, as its own proper cause." Thus according to Aquinas, angels have no power to command matter to assume complex forms; only God, the Creator of matter, can do that. St. Augustine says the same thing in De Trinitate iii, 8: "We must not suppose that this corporeal matter serves the angels at their nod, but rather that it obeys God thus."

In his Summa Contra Gentiles Book II chapter 43, paragraph 6, Aquinas argues that the heavenly bodies alone are unable to generate the forms of many animals from matter; seed (from a parent) is required as well, for the generation of these animals:

[6] ...There are, however, many sensible forms which cannot be produced by the motion of the heaven except through the intermediate agency of certain determinate principles pre-supposed to their production; certain animals, for example, are generated only from seed. Therefore, the primary establishment of these forms, for producing which the motion of the heaven does not suffice without their pre-existence in the species, must of necessity proceed from the Creator alone.

Where Professor Tkacz contradicts Aquinas:

Professor Tkacz, on the other hand, argues that "nature and her operations are autonomous in the sense that nature operates according to the way she is, not because something outside of her is acting on her." That would exclude the possibility of angels acting on heavenly bodies, in order to regulate biological processes taking place on Earth.

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A female Eastern Grey kangaroo and her joey. Courtesy of Fir0002/Flagstaffotos.
GFDL license address: http://en.wikipedia.org/wiki/File:Kangaroo_and_joey03.jpg.
According to Professor Tkacz, God maintains living creatures in being, but does not cause their operations, such as giving birth.
According to Aquinas, God causes every action of natural things, and He acts in every agent immediately.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 5

"SMOKING GUN" Number 5:

GOD IS AN IMMEDIATE CAUSE OF EACH AND EVERY EFFECT OCCURRING IN THE NATURAL WORLD. WHENEVER GOD WORKS IN CO-OPERATION WITH A NATURAL CAUSE IN ORDER TO PRODUCE AN EFFECT, THE NATURAL AGENT PRODUCING THAT EFFECT IS ALSO AN IMMEDIATE CAUSE, BUT IT OPERATES AS AN INSTRUMENT OF GOD, WHO IS THE PRINCIPAL AGENT. (CONCURRENTISM.)

Aquinas was a proponent of concurrentism: he taught that whenever a natural agent makes something happen, God also makes it happen, as an immediate cause.

According to Aquinas, whenever a natural agent brings about an effect, God acts as the principal agent, moving the natural agent as His instrument to produce the desired effect. God is an immediate cause of every effect brought about in the natural world, because every such effect results directly from an action of God's. Hence God is an immediate cause of each and every natural change, and not just an immediate cause of the being of things. God really does "reach into" nature's operations.

This thesis is an especially important one: if it is true, then there is no theological reason why God cannot "manipulate" or "adjust" Nature to produce some special effects (e.g. forms with a high degree of specified complexity), as He is already an immediate cause of each and every natural effect. In other words, God is not aloof from the operations of Nature; He doesn't leave Nature alone to do her stuff, as Professor Tkacz contends. In Part Four of my reply to Professor Tkacz, I'll argue that concurrentism plays a key role in establishing a case that Intelligent Design offers us a credible picture of the way God interacts with the world. Once concurrentism is accepted, the theological objections to Intelligent Design disappear, and Professor Tkacz's case against ID collapses.

First, a few useful definitions...

How does God act in Nature? Historically, three positions have been put forward in answer to this question: "conservationism," "concurrentism," and "occasionalism." The following definitions are taken from The Stanford Encyclopedia of Philosophy (article: "Occasionalism")

We might distinguish the three positions by the degree of causal activity assigned to God and the creature respectively, when a natural event takes place.

At one end is conservationism, which keeps divine causal involvement to a minimum. According to conservationism, while God conserves substances with their powers in existence, when creatures are causally active in bringing about their natural effects, God's contribution is remote or indirect. In other words, God's causal contribution consists in merely conserving the being or esse of the creature in question along with its power, and the causal activity of the creature is in some straightforward sense the creature's own and not God's (Freddoso 1991, 554).

At the other end is occasionalism, where divine causal activity is maximal and creaturely causal activity is non-existent, since divine causal activity is the only type of genuine causality. Creatures provide at most an occasion for God's activity, which is direct and immediate in bringing about all effects in nature.

Concurrentism (or "divine concurrentism") can then be seen as occupying the middle ground. Concurrentists hold that when a natural effect is produced, it is immediately caused by both God and the creature. (Highlighting and paragraphs mine - VJT.)

As we'll see later on, Professor Tkacz is a conservationist. Aquinas, on the other hand, was a concurrentist.

What do concurrentists mean by "immediate"?

Briefly, concurrentists mean two things by the term "immediate."

First, God acts through natural agents: they are His instruments, whereby He achieves the effects that He wants to bring about. Here, the effect is immediate because it is directly intended by God as an end; natural agents being the means to producing it.

Second, God acts in co-operation with each natural agent. God is not just a remote cause: He acts in partnership with each and every natural agent in a causal chain. His co-operation with each agent is absolutely vital: for without God's co-operation, no action by a natural agent would produce any effect whatsoever. The natural agent would still retain its powers and dispositions, but it would be prevented from exercising them if God "turned off the taps" on His side.

As we'll see below, Aquinas explicitly affirmed that God acts through natural agents (immediacy in the first sense), and he implicitly affirmed that God acts in co-operation with each natural agent (immediacy in the second sense). Professor Tkacz, on the other hand, explicitly denies that God is an immediate cause of natural effects, in both senses of the word "immediate."

Where Aquinas says all this:

Here are the relevant quotes from St. Thomas Aquinas himself, which conclusively establish that he was a concurrentist. The quotes below come from two works by Aquinas: his Quaestiones Disputatae De Potentia Dei (Disputed Questions Relating to the Power of God) and the Summa Contra Gentiles. They conclusively establish that Aquinas believed that God acts through natural agents (immediacy in the first sense of the word, as defined above).

(1) How Aquinas articulated his concurrentism in his Quaestiones Disputatae De Potentia Dei

In Aquinas' Quaestiones Disputatae De Potentia Dei (Disputed Questions Relating to the Power of God) Q. III art. VII, he addresses the question: does God work in the operations of Nature? This is a very lengthy article by Aquinas. Readers who scroll down past the objections, to the paragraph beginning with the sentence, "It must be observed that one thing may be the cause of another's action in several ways," can verify that it contains the following statements by Aquinas:

It must be observed that one thing may be the cause of another's action in several ways. First, by giving it the power to act: ... In this way God causes all the actions of nature, because he gave natural things the forces whereby they are able to act, ... and thus God may be said to be the cause of an action by both causing and upholding the natural power in its being. [S]econdly, the preserver of a power is said to cause the action; thus a remedy that preserves the sight is said to make a man see... [T]hirdly, a thing is said to cause another's action by moving it to act: whereby we do not mean that it causes or preserves the active power, but that it applies the power to action, even as a man causes the knife's cutting by the very fact that he applies the sharpness of the knife to cutting by moving it to cut. And since the lower nature in acting does not act except through being moved, ... so that we must eventually trace its movement to God, it follows of necessity that God causes the action of every natural thing by moving and applying its power to action.... Hence, fourthly, one thing causes the action of another, as a principal agent causes the action of its instrument: and in this way again we must say that God causes every action of natural things. For the higher the cause the greater its scope and efficacity: and the more efficacious the cause, the more deeply does it penetrate into its effect, and the more remote the potentiality from which it brings that effect into act....

As a "mere conservationist" who maintains that God maintains all creatures in being as the Author of their natures, but that creatures are autonomous causes of their own operations, Professor Tkacz would presumably endorse the first and second of Aquinas' four ways in which God causes creatures' actions, but not the third and fourth. Because he explicitly denies that God operates on Nature, Tkacz cannot maintain that God causes a creature's actions "by moving it to act" as Aquinas does in his third way above. And because he explicitly affirms the principle of the Autonomy of Nature, Tkacz would deny that God causes creatures' actions "as a principal agent causes the action of its instrument," Aquinas does in his fourth way.

Aquinas is even more explicit about his concurrentism in the following paragraph:

If, then, we consider the subsistent agent, every particular agent is immediate to its effect: but if we consider the power whereby the action is done, then the power of the higher cause is more immediate to the effect than the power of the lower cause; since the power of the lower cause is not coupled with its effect save by the power of the higher cause: wherefore it is said in De Causis (prop. i) that the power of the first cause takes the first place in the production of the effect and enters more deeply therein.... Therefore God is the cause of everything's action inasmuch as he gives everything the power to act, and preserves it in being and applies it to action, and inasmuch as by his power every other power acts. And if we add to this that God is his own power, and that he is in all things not as part of their essence but as upholding them in their being, we shall conclude that he acts in every agent immediately, without prejudice to the action of the will and of nature.

To the objection that one and the same operation (i.e. the production of some natural effect) cannot be performed by two distinct agents (God and the natural agent), Aquinas replied that God and the natural agent play complementary roles in producing the effect, where the natural agent works as an instrument of God:

Reply to the Third Objection. In that operation whereby God operates by moving nature, nature itself does not operate: and even the operation of nature is also the operation of the divine power, just as the operation of an instrument is effected by the power of the principal agent. Nor does this prevent nature and God from operating to the same effect, on account of the order between God and nature.

Aquinas also addresses a couple of objections to concurrentism, relating to whether God's concurrent agency renders the natural agency of creatures redundant:

Reply to the Fourth Objection. Both God and nature operate immediately, although as already stated there is order between them of priority and posteriority.

Reply to the Sixteenth Objection. God acts perfectly as first cause: but the operation of nature as second cause is also necessary. Nevertheless God can produce the natural effect even without nature: but he wishes to act by means of nature in order to preserve order in things.

(2) How Aquinas answered objections to concurrentism in his Summa Contra Gentiles

Finally, in his Summa Contra Gentiles Book III, chapter 70 (How the same effect is from God and from a natural agent), Aquinas considers three objections to concurrentism, and then rebuts them all, in the same way that a modern concurrentist would:

Arg. 1. One action, it seems, cannot proceed from two agents. If then the action, by which a natural effect is produced, proceeds from a natural body, it does not proceed from God.

Arg. 2.When an action can be sufficiently done by one, it is superfluous to have it done by more: we see that nature does not do through two instruments what she can do through one. Since then the divine power is sufficient to produce natural effects, it is superfluous to employ also natural powers for the production of those same effects. Or if the natural power sufficiently produces its own effect, it is superfluous for the divine power to act to the same effect.

Arg. 3. If God produces the whole natural effect, nothing of the effect is left for the natural agent to produce.

Upon consideration, these arguments are not difficult.

Reply 1. The power of the inferior agent depends upon the power of the superior agent, inasmuch as the superior agent gives to the inferior the power whereby it acts, or preserves that power, or applies it to action; as a workman applies a tool to its proper effect, frequently however without giving the tool the form whereby it acts, nor preserving it, but merely giving it motion. The action therefore of the inferior agent must proceed from that agent not merely through its own power, but through the power of all superior agents, for it acts in virtue of them all.... As then it is not absurd for the same action to be produced by an agent and the power of that agent, so neither is it absurd for the same effect to be produced by an inferior agent and by God, by both immediately, although in different manners.

Reply 2. Though a natural thing produces its own effect, it is not superfluous for God to produce it, because the natural thing does not produce it except in the power of God. Nor is it superfluous, while God can of Himself produce all natural effects, for them to be produced by other causes: this is not from the insufficiency of God's power, but from the immensity of His goodness, whereby He has wished to communicate His likeness to creatures, not only in point of their being, but likewise in point of their being causes of other things.

Reply 3. When the same effect is attributed to a natural cause and to the divine power, it is not as though the effect were produced partly by God and partly by the natural agent: but the whole effect is produced by both, though in different ways, as the same effect is attributed wholly to the instrument, and wholly also to the principal agent.

Proof that Aquinas believed God co-operates with each natural agent

Aquinas implicitly affirmed that God acts in co-operation with each natural agent (immediacy in the second sense of the word, as defined above). This can be seen in his discussing of a famous miracle recorded in Scripture: the miracle of Shadrach, Meshach and Abednego in the fiery furnace.

The miracle of Shadrach, Meshach and Abednego in the fiery furnace, described in chapter 3 of the book of Daniel, is often appealed to by concurrentists, in order to demonstrate that God moves natural agents immediately, by His own direct agency. According to the Biblical account, the flesh of these three young men was exposed unprotected to real fire, and yet they survived unscathed. At the same time, the fire was so hot that it consumed the soldiers who ushered them into the furnace. Professor Alfred Freddoso, in his Comment on Peter van Inwagen's "The Place of Chance in a World sustained by God", addresses the question of how God accomplished this miracle, and in particular, how God saved the first young man, Shadrach. If concurrentism is true, then all God needed to do was withhold His intention that the fire should burn Shadrach as it normally would, in order to prevent Shadrach from being burned. The fire would still have retained its disposition to burn, but without God's active co-operation, it would have had no effect whatsoever on Shadrach. But if concurrentism is not true, and God is only a remote cause of natural effects, then He could only have saved Shadrach from being burned by either destroying or "magically" overpowering the fire. Both of these methods require God to oppose or struggle against His own creatures, as Professor Freddoso points out in the article cited above:

Think of Shadrach sitting in the fiery furnace.... How, on the weak deist view [i.e. the view that God is at most a remote cause of natural changes - VJT], can God save Shadrach? Only, it seems, by either (i) taking from the fire its power to consume Shadrach, which is inconsistent with the soldiers' being incinerated but in any case amounts (or so the anti-deists all claim) to destroying the fire and in that sense overpowering it; or (ii) endowing Shadrach's clothing and flesh with a special power of resistance, in which case God is opposing His creature, the fire; or (iii) placing some impediment (say, an invisible heat-resistant shield) between Shadrach and the flames, in which case God is yet again resisting the power of the fire. By contrast, on the occasionalist and concurrentist models, God accomplishes this miracle simply by withholding His own action. The (real) fire is, as it were, beholden to God's word; He does not have to struggle with it or overcome it or oppose it. The fire's natural effect cannot occur without God's action, and in this case God chooses not to act in the way required. An elegant account, and one that does not in any way give any creature a power that God must oppose.

Leaving aside the theological impropriety of God having to struggle against His own creatures (on the "mere conservationist" account), the concurrentist explanation of the miracle of the fiery furnace also has the advantage of being more parsimonious and less "magical" than the "mere conservationist" explanation. On the former account, God simply withholds His co-operation with the natural agent (fire) when it is directed at Shadrach; whereas on the latter account, God has to endow Shadrach with a new magical power, or create an invisible entity, in order to protect him.

The following extract from Aquinas' Quaestiones Disputatae De Potentia Dei (Disputed Questions Relating to the Power of God) Q. VI art. II shows that St. Thomas Aquinas' reasoning on miracles contrary to Nature agrees with that of Professor Freddoso. In this passage, Aquinas addresses the question: can everything that God does without natural causes or contrary to the course of nature be called a miracle? Aquinas distinguishes three kinds of miracles, and explains that in the case of miracles that are contrary to Nature, the natural agent retains its power or disposition to produce its customary natural effect, even when God prevents it from producing this effect and chooses to produce some other effect, instead. Thus in the fiery furnace of Daniel, the fire retained its disposition to burn - and yet it did not burn the three young men, simply because God did not want it to burn them:

Reply to the Third Objection. It is customary to divide the miraculous works of God into those which are done above, those which are done against, and those which are done without nature. - A miracle is above nature when God produces an effect which nature is wholly incapable of producing. This happens in two ways. First, when God induces into matter a form which nature is utterly unable to induce, for instance, the form of glory which God will induce into the bodies of the elect; and again the Incarnation of the Word. Secondly when nature, although able to induce a particular form into some matter, is unable to induce it into this particular matter: thus nature is able to produce life, but not to produce it in this corpse. A miracle is contrary to nature, when nature retains a disposition contrary to the effect produced by God: for instance when he prevented the three children in the furnace from being hurt, while the fire retained the power to bum; and when the waters of the Jordan stood (Jos. iii, 16) while retaining the force of gravity; and again when a virgin gave birth to a son. - A miracle is done by God without nature, when he produces an effect that nature can produce, but in a manner of which nature is incapable. This may be either through lack of the instruments which nature is wont to employ, as when Christ changed water into wine (Jo. ii): for nature can do this in a certain way, the water absorbed by the vine for the purpose of nourishment being converted in due time into the juice of the grape by the process of assimilation: or, because the effect is produced by God more copiously than when produced by nature, for instance, the frogs that were brought forth in Egypt (Exod. viii, 6): or because it is produced in less time than nature can produce it, as when a person is instantly cured through the prayer of a saint, for nature could have done this, yet not at once but by degrees, not now but at another time: for instance, the miracle already quoted wrought on Peter's mother-in-law. Evidently then all such works, if we take into account both the substance and the manner of the thing done, surpass the faculty of nature.

When Aquinas asserted that the fire in Daniel's fiery furnace retained its disposition to burn even while God prevented it from burning the three young men, then he was implicitly conceding that the dispositions of natural agents do not suffice for the production of their natural effects. Something else is needed: God's active co-operation with the natural agents in question. If God were to refuse to co-operate with these agents, then they would be prevented from exercising their powers. That's the concurrentist position, in a nutshell.

Objection 1:

In his Summa Theologica I, q. 105 art. 1, Aquinas argues that God can move matter immediately to receive a form if He so wishes, and in his Summa Theologica I, q. 105 art. 2, he likewise asserts that God can imprint a form immediately on some matter, if He wishes to. Doesn't this imply that in the ordinary course of events, God is not an immediate cause of natural effects?

Reply:

Not at all. It simply implies that that in the ordinary course of events, God works through natural agents in order to produce natural effects, but that He is also capable of producing those effects without natural agents. We need to distinguish two senses of "immediate": (a) without the aid of any secondary agent; and (b) directly intended by God, working through and in co-operation with a natural, secondary agent. The passages cited above refer to "immediate" in the first sense; the doctrine of concurrentism (which Aquinas held, and which I am defending here) refers to "immediate" in the second sense. Hence Aquinas writes that when God co-operates with a natural agent, "Both God and nature operate immediately, although as already stated there is order between them of priority and posteriority" (Quaestiones Disputatae De Potentia Dei (Disputed Questions Relating to the Power of God) Q. III art. VII, Reply to Objection 4).

Objection 2:

In claiming that natural effects are directly intended by God, aren't you making God the author of evil, if the natural agent does something bad? And what about God's co-operation with moral agents? When Brutus stabbed Julius Caesar, did God directly intend that Brutus' dagger should penetrate Caesar's body?

Reply:

No. I discuss this objection at further length in Part Four of my reply to Professor Tkacz, in "Fatal Flaw number 3". Briefly, I argue that God acts as a universal cause whenHe co-operates with a natural agent (e.g. the flames of a forest fire) that causes a harmful effect, and not as a particular cause. As a universal cause, and as the Author of Nature, God is morally responsible for the general features of the effect (e.g. the fact that fires burn combustible bodies in their path), but that does not necessarily make him responsible for the particular details in each instance (e.g. the fact that this fire burned that unlucky animal). And when God co-operates with a moral agent, who has a will of his/her own, God is in no way responsible for the moral evil of that agent's act. When Brutus stabbed Caesar, God, in co-operating with Brutus, intended that his hands should work as they normally would when picking up things (be they spoons, gifts or daggers), and that the dagger held by Brutus should remain in his hand as it normally would when held firmly. What God did not intend was that Brutus should stab Julius Caesar with this dagger. In the words of Aquinas, "Forasmuch as the first cause has more influence in the effect than the second cause, whatever there is of perfection in the effect is to be referred chiefly to the first cause: while all defects must be referred to the second cause which does not act as efficaciously as the first cause" (Quaestiones Disputatae De Potentia Dei (Disputed Questions Relating to the Power of God) Q. III art. VII, Reply to Objection 15). Hence God is in no way the Author of evil.

Proof that Aquinas' teacher, St. Albert the Great, was a concurrentist

Finally, I'd like to quote a brief extract from an essay by Professor Alfred Freddoso entitled, God's General Concurrence With Secondary Causes: Why Conservation Is Not Enough (Philosophical Perspectives 5:553-585, 1991), where on page 555, he cites a brief passage from St. Thomas Aquinas' own teacher, St. Albert the Great (c. 1200-1280), who was also a concurrentist. On page 579, Professor Freddoso provides the full reference for his citation from St. Albert, preceded by his comments:

Albertus Magnus, Commentarii in II Sententiarum, dist. 35, sect. I, art. 7, in Opera Omnia (Paris, 1894), vol. 27, p. 575. Albert's comment occurs within a discussion of whether every act, good or evil, is immediately from God. In order to exonerate God of any responsibility for evil acts, some had claimed that secondary causes produce evil effects on their own without God's immediate causal influence:

Some have claimed that the will is sufficient of itself for an evil act, but not for a good act ... Since the moderns have seen that it is more perfect to act than to exist, they have seen that that which does not exist on its own (a se) cannot remain in existence on its own, either - and much less can it act on its own. And this is the reason why that other opinion has all but disappeared from the lecture hall and is regarded as heretical by many moderns.

St. Albert's language in this passage ("regarded as heretical") is very strong, and I cite it only in order to show the passionate conviction with which thirteenth century believed that "that which does not exist on its own cannot ... act on its own" - even when performing an evil act. On the basis of this passage alone, I think we can safely say that Aquinas would have totally rejected Professor Tkacz's principle of the Autonomy of Nature.

The Principle of Maximal Agency

In an essay by Professor Alfred Freddoso entitled, God's General Concurrence With Secondary Causes: Why Conservation Is Not Enough (Philosophical Perspectives 5:553-585, 1991), Freddoso cites four arguments by Suarez for concurrentism. The last and most persuasive of these is that we should credit God with being as causally active in the world as He possibly can be, without prejudice to creatures. Concurrentism is fully compatible with the genuine causal agency of creatures, and it gives God a greater role in the world than "mere conservationism"; hence we should accept it as true. I would therefore like to propose what I call a Principle of Maximal Agency: God is as causally active in the world as He possibly can be, and His creatures are as causally active as they possibly can be. This principle sums up the flavour of Aquinas' thought, and shows why he had no problem with embracing concurrentism.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz is not a concurrentist like Aquinas. He is a "mere conservationist," who maintains (as Aquinas does) that God maintains all creatures in being as the Author of their natures, but (unlike Aquinas) he also maintains that creatures are autonomous causes of their own operations. Thus God is not a direct and immediate cause of every change brought about by natural agents; they just act that way because it is their nature to do so, and because God gave them their natures. (I'll have a lot more to say about this in Part Three of my response to Professor Tkacz.)

(1) The following quotes, taken together, establish conclusively that Professor Tkacz would deny the view that God acts through natural agents, as a principal agent acting through his instruments.

In his original talk given to the Gonzaga Socratic Club, Professor Tkacz said:

[M]odern Thomists distinguish between the existence of natural beings and their operations. God causes natural beings to exist in such a way that they are the real causes of their own operations...

It cannot be that God "reaches into" the normal operations of hippopotamuses to cause them to give live birth...

[N]ature and her operations are autonomous in the sense that nature operates according to the way she is, not because something outside of her is acting on her. God does not act on nature the way a human being might act on an artifact to change it. Rather, God causes natural beings to be in such a way that they work the way they do. Hippopotamuses give live birth because that is the sort of thing they are. Why are there such things as Hippopotamuses? Well, nature produced them in some way. What way did nature produce them and why does nature produce things in this way? It is because God made the whole of nature to operate in this way and produce by her own agency what she produces.

In his article for the journal This Rock, Professor Tkacz wrote:

God does not intervene into nature nor does he adjust or "fix up" natural things.

(2) The following quote establishes that Professor Tkacz would also deny the concurrentist view that God acts in co-operation with each natural agent, whenever it produces its natural effect.

In the revised version of his talk, Professor Tkacz writes:

According to Thomism, God is indeed the Author of nature, but as its transcendent ultimate cause, not as another natural cause alongside the other natural causes.

Note the word "alongside." I should add that Tkacz is not being fair to concurrentists here: what they hold is that God is a Transcendent Cause, Who acts in co-operation with natural causes, in such a way that if He were to withdraw His co-operation for some reason, the usual natural effect would not occur. I'll have more to say about this in Part Four of my reply to Professor Tkacz.

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A hippopotamus. According to Aquinas, it would still be a hippopotamus even if God had produced it immediately; according to Professor Tkacz, it wouldn't.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 6

"SMOKING GUN" Number 6:

A THING DOESN'T NEED TO HAVE A NATURAL ORIGIN, IN ORDER TO BELONG TO A NATURAL KIND.

According to Aquinas, a thing produced immediately by God's supernatural agency can still be a member of a natural kind. (Natural kinds are either groups of things sharing a common nature - e.g. hippopotamuses - or larger, generic categories of things that do - e.g. mammals. Natural kinds are generally contrasted with arbitrary categories, whose members are not distinguished by any fundamental underlying similarities, such as "animals with brown hair," and also with purely artificial categories, such as "animals starting with the letter 'H.'")

Aquinas taught that a thing doesn't need to have a natural origin, in order to belong to a natural kind. Thus a hippopotamus produced immediately by God would still be a hippopotamus, and a human being produced immediately by God would still be a human being. (Note: when I say "produced," I mean: generated from pre-existing matter, whether it be the dust of the ground, as in the book of Genesis, or the embryo of an unspecialized mammal ancestral to hippos, whose genes God altered to make it a hippopotamus, as some Intelligent Design proponents would maintain.) Similarly, a hippopotamus created ex nihilo by God would still be a hippopotamus, and a human being created ex nihilo by God would still be a human being.

Where Aquinas says this:

In his Summa Theologica I, q. 92 art. 2, reply to objection 2, Aquinas asks whether woman should have been made for man, and answers in the affirmative. In his reply, Aquinas counters an objection that things of the same species should be made from the same matter. St. Thomas acknowledges that each kind of entity can have only one kind of natural origin: it has to originate from matter of the right kind. But then he goes on to say that God is quite capable of supernaturally producing a man and a woman (Adam and Eve) from any matter He likes, and that human beings produced in this way are of the same species (hence, they are the same kind of entity) as human beings whose bodies are generated by natural means:

Objection 2. Further, things of the same species are of the same matter. But male and female are of the same species. Therefore, as man was made of the slime of the earth, so woman should have been made of the same, and not from man.

Reply to Objection 2. Matter is that from which something is made. Now created nature has a determinate principle; and since it is determined to one thing, it has also a determinate mode of proceeding. Wherefore from determinate matter it produces something in a determinate species. On the other hand, the Divine Power, being infinite, can produce things of the same species out of any matter, such as a man from the slime of the earth, and a woman from out of man.

Aquinas articulates this conclusion even more clearly in his Summa Theologica I, q. 92 art. 4, where he addresses the question of whether the first woman (Eve) was formed immediately by God. Each species, he explains, can only be naturally generated in one particular way, i.e. from a particular kind of matter. Only God, "the Author of nature," can generate an individual of that species in a supernatural way. Thus a man cannot be naturally generated from the slime of the earth or from the flesh of a woman; however, a man can be supernaturally generated in these ways by God.

I answer that, As was said above (I, q. 92, art. 2, ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man.

In his Summa Contra Gentiles Book III chapter 99, paragraph 5 (That God Can Work Apart From The Order Implanted In Things, By Producing Effects Without Proximate Causes), Aquinas argues that God, whose intellect encompasses everything, can bring about whatever effects he wants, without having to follow any set order of things, such as we find in Nature. Hence He is quite capable of forming a man (Adam) from the slime of the earth, without having to make use of semen, as in the ordinary course of Nature:

[5] Moreover, the order of things flows forth from God into things, according as it is foreknown in His intellect. We observe, for example, in human affairs that the head of a state imposes on the citizens an order that is preconceived within himself. But the divine understanding is not determined by necessity to this particular order, in the sense that He can understand no other order; because even we can apprehend intellectually another order. For instance, it can be understood by us that God may form a man from the earth without the use of semen. Therefore, God can bring about the proper effect of these causes without lower causes.

In his Summa Contra Gentiles Book IV, chapter 45, paragraphs 5 & 7 (That It Became Christ To Be Born Of a Virgin), Aquinas explains why God would have been quite capable of producing the body of an unborn child - Jesus Christ - from the flesh of the Virgin Mary, and that being generated in this way doesn't make him any less human:

[5] And for all that, this mode of generation detracts in nothing from the true and natural humanity of Christ, even though He was generated differently from other men. For clearly, since the divine power is infinite, as has been proved, and since through it all causes are granted the power to produce an effect, every effect whatever produced by every cause whatever can be produced by God without the assistance of that cause of the same species and nature. Then, just as the natural power which is in the human seed produces a true man who has the human species and nature, so the divine power, which gave such power to the seed, can without its power produce that effect by constituting a true man who has the human species and nature.

Aquinas then considers two competing theories of human reproduction that were known to him, in the thirteenth century: the prevailing theory of Aristotle, according to which the mother alone contributed the matter that went into the making of her offspring, and an alternative view, according to which both parents contributed matter that went into the making of their offspring. However, both of these theories acknowledged the father had a vital role: his "seed" was supposed to kick-start the developmental process that led to a new human being. Aquinas argues that if Aristotle's theory is correct then Jesus' body was made from matter taken from His mother, just as our bodies are - the only difference being that God kick-started the developmental process, rather than the "seed" of a man. Alternatively, even if both parents contribute matter that helps make the body of their offspring, Aquinas argued that God in His infinite power was perfectly capable of using matter taken from a woman's body to make a baby, if He so wished. Aquinas continues:

[7] Thus, then, by the divine power the matter taken from the woman alone can be reduced at the end of the generation to a disposition identical with that which matter has if taken simultaneously from the male and female. Hence, there will be no unlikeness by reason of diversity of matter between the body of Christ which was formed by the divine power out of matter taken from the mother alone, and our bodies which are formed by the natural power from matter, even though they are taken from both parents. Surely this is clear; the matter taken simultaneously from a man and a woman and that "slime of the earth" (Gen. 2:7) of which God formed the first man (very certainly a true man and like us in everything) differ more from one another than from the matter taken solely from the female from which the body of Christ was formed. Hence, the birth of Christ from the Virgin does not at all diminish either the truth of His humanity or His likeness to us. For, although a natural power requires a determined matter for the production of a determined effect therefrom, the divine power, the power able to produce all things from nothing, is not in its activity circumscribed within determinate matter.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz argues that because Nature is autonomous in "her" operations, living things can only be properly understood within the larger context of Nature. To understand a living thing properly is to understand it as a product of Nature. The various kinds of living things are defined by their manner of generation, which has to be natural; otherwise they would be unintelligible. Hence a living thing's nature (i.e. essence) precludes it from being produced immediately by a supernatural cause.

In his original talk given to the Gonzaga Socratic Club, Professor Tkacz said:

Why are there such things as Hippopotamuses? Well, nature produced them in some way. What way did nature produce them and why does nature produce things in this way? It is because God made the whole of nature to operate in this way and produce by her own agency what she produces.

In his article for the journal This Rock, Professor Tkacz wrote:

...Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature. The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

[The Ultimate Cause of Everything]

Yet, the evidence for God's Creation of the natural universe is the known fact - a fact that we know on the basis of our scientific research - that natural things are intelligible. If they are intelligible, they are so as the products of nature - that is, they are intelligible in terms of their natural causes.

The passage cited above appears to say that a natural thing's very intelligibility (as a thing of a certain kind) hinges on its having a natural cause.

Thus Aquinas' conclusion is diametrically opposed to that of Professor Tkacz.

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Darwin's Tree of Life - and a modern phylogenetic version from Wikipedia.
According to Aquinas' epistemological principles, we should not believe in either tree until scientists can demonstrate that all of the various branchings could have occurred, as a result of processes still occurring today.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 7

"SMOKING GUN" Number 7:

NATURE ALWAYS WORKS IN THE SAME REGULAR, REPEATABLE WAY WHEN PRODUCING EACH KIND OF THING: IT NEEDS THE RIGHT SORT OF STUFF TO WORK ON, PLUS AN AGENT WITH ADEQUATE CAUSAL POWER IN ORDER TO GENERATE THE FORM OF THAT KIND OF THING. (HYPER-UNIFORMITARIANISM, MATERIAL SPECIFICITY AND CAUSAL ADEQUACY.)

Aquinas believed in an extreme form of uniformitarianism, which I'll call hyper-uniformitarianism. He thought that each kind of thing in Nature is naturally generated in one and the same way, which is regular and repeatable. Note: "in one and the same way" does not mean "by one and only one pathway," but rather, "by an agent of adequate power, acting on the right kind of stuff to produce its characteristic effect." See (c) and (d) below.

(a) Aquinas acknowledged that God sometimes uses chance events to accomplish His purposes, with particular individuals ("singulars"). However, chance cannot account for the various kinds of things found in Nature. The natural generation of the various kinds of things in our world always occurs as a result of regular, law-governed occurrences, and not as a result of chance events.

(b) According to Aquinas, the generation of each kind of thing in the natural world always occurs according to regular, repeatable processes, in which each natural agent tends to produce its characteristic effect, unless something prevents it from doing so.

(c) According to Aquinas, each of the various kinds of things we see in the natural world can only be naturally generated from the right kind of matter. For instance, each kind or species of living thing is generated from its own determinate matter. Thus animals generated from the "seed" of their parents cannot be generated in any other way.

(d) According to Aquinas, each kind of thing found in Nature can only be naturally generated by an agent of adequate power - i.e. one whose power is sufficient to generate the form characterizing that kind of thing.

The foregoing points have two very significant corollaries:

Corollary 1 (a scientific corollary): Neither life itself nor the various kinds of complex organisms could have originated as a result of "accidental" (i.e. chance-only) processes. If life arose naturally, it can only have been through law-governed processes.

Corollary 2 (an epistemic corollary): We shouldn't believe evolutionists' explanations of the origin of life or of various kinds of complex organisms, unless they can replicate them experimentally.

WHERE DOES AQUINAS SAY ALL THIS?

Let's examine (a), (b), (c) and (d) in turn.

(a) Aquinas acknowledged that God sometimes uses chance events to accomplish His purposes, with particular individuals ("singulars"). However, chance cannot account for the various kinds of things found in Nature. The natural generation of the various kinds of things in our world always occurs as a result of regular, law-governed occurrences, and not as a result of chance events.

Where Aquinas says this:

The following three passages show that while Aquinas readily acknowledged the occurrence of chance events in the lives of individuals, and viewed these events as being perfectly compatible with Divine Providence, he was quite emphatic that chance played absolutely no role in explaining the origin of the different kinds of things occurring in Nature.

Aquinas discusses chance in his Summa Contra Gentiles, Book III, chapter 74 (That Divine Providence does not exclude fortune and chance). In paragraph 4, he gives an example of a chance event, relating to two individuals:

[1] It is also apparent from the foregoing that divine providence does not take away fortune and chance from things.

[2] For it is in the case of things that happen rarely that fortune and chance are said to be present. Now, if some things did not occur in rare instances, all things would happen by necessity. Indeed, things that are contingent in most cases differ from necessary things only in this: they can fail to happen, in a few cases. But it would be contrary to the essential character of divine providence if all things occurred by necessity, as we showed. Therefore, it would also be contrary to the character of divine providence if nothing were to be fortuitous and a matter of chance in things...

[4] Besides, the large number and variety of causes stem from the order of divine providence and control. But, granted this variety of causes, one of them must at times run into another cause and be impeded, or assisted, by it in the production of its effect. Now, from the concurrence of two or more causes it is possible for some chance event to occur, and thus an unintended end comes about due to this causal concurrence. For example, the discovery of a debtor, by a man who has gone to market to sell something, happens because the debtor also went to market. Therefore, it is not contrary to divine providence that there are some fortuitous and chance events among things.

In his Summa Contra Gentiles, Book III, chapter 75 (That God's Providence applies to contingent singulars), Aquinas makes it clear that the chance events he is envisaging relate to individuals, or singulars as he calls them, and not to kinds, or universals:

[1] It is obvious from what we have shown that divine providence reaches out to singulars that are generable and corruptible.

[2] Except for the fact of their contingency, and the fact that many of them come about by chance and fortune, it does not seem that providence is inapplicable to them. For it is only on this basis that they differ from incorruptible things, and the universal natures of corruptible things, to which providence does apply, as people say. But contingency is not incompatible with providence, nor are chance or fortune or voluntary action, as we have shown. Therefore, nothing prohibits providence from also applying to these things, just as it does to incorruptible and universal things.

In his Summa Contra Gentiles, Book II, chapter 39, paragraphs 3-4 (That the distinction of things is not the result of chance), Aquinas argues that while chance may account for the differences between individuals of the same species (who have the same kind of form but differ in their matter), it cannot account for the differences in form between various kinds, or species:

[3] Moreover, chance is found only in things that are possibly otherwise; and the source of this possibility is matter and not the form, which indeed determines the matter, reservoir of multiple possibilities, to one. It follows that those things whose distinction from one another is derived from their forms are not distinct by chance, although this is perhaps the case with things whose distinction stems from matter. Now, the distinction of species is derived from the form, and the distinction of singulars of the same species is from matter. Therefore, the distinction of things in terms of species cannot be the result of chance; but perhaps the distinction of certain individuals can be the result of chance.

[4] Again, since matter is the principle and cause of fortuitous things, as we have shown, in the making of things that are generated from matter there can be chance. Now, we proved above that the first production of things into being was not from matter. Therefore, chance can have had no place in it. Nevertheless, that production necessarily involved the distinction of the things produced. For in the world of creation there are many things which are neither generated from one another nor from some one common source, because they are not united in the possession of a common matter. It is impossible, therefore, that the distinction of things should be the result of chance.

(b) According to Aquinas, the generation of each kind of thing in the natural world always occurs according to regular, repeatable processes, in which each natural agent tends to produces its characteristic effect, unless something prevents it from doing so.

In his Summa Contra Gentiles Book 1 chapter 44, paragraph 7 (That God Is Intelligent), Aquinas argues from the constancy and regularity of Nature, which always works in the same way, barring the occasional mishap:

[7] Again, that which tends determinately to some end either has set itself that end or the end has been set for it by another. Otherwise, it would tend no more to this end than to that. Now, natural things tend to determinate ends. They do not fulfill their natural needs by chance, since they would not do so always or for the most part, but rarely, which is the domain of chance. Since, then, things do not set for themselves an end, because they have no notion of what an end is, the end must be set for them by another, who is the author of nature. He it is who gives being to all things and is through Himself the necessary being. We call Him God, as is clear from what we have said. But God could not set an end for nature unless He had understanding. God is, therefore, intelligent.

In his Summa Contra Gentiles Book III, chapter 85, paragraph 5 (That the Celestial Bodies Are Not the Causes of our Acts of Will and Choice), Aquinas speaks of natural causes as being determined to produce the same kind of result, unlike human choices, which are free. Aquinas is not saying here that Nature operates deterministically, in a Laplacean fashion. Rather, he is simply saying that the same kinds of causes always tend to produce the same kinds of effects, unlike human agents:

[5] Moreover, things that are done naturally are brought to their end by determinate means, and so they always happen in the same way, for nature is determined to one result. But human choices tend to their end in various ways, both in moral actions and in artistic productions. Therefore, human choices are not accomplished by nature.

Finally, in his Summa Theologica I, q. 19 art. 4 Aquinas asks whether the will of God is the cause of things, and answers in the affirmative, basing one of his arguments on the constancy of Nature. Aquinas argues that each natural agent tends to produce its characteristic effect, unless something prevents it:

I answer that, We must hold that the will of God is the cause of things; and that He acts by the will, and not, as some have supposed, by a necessity of His nature. This can be shown in three ways:

First, from the order itself of active causes....

This is shown, secondly, from the character of a natural agent, of which the property is to produce one and the same effect; for nature operates in one and the same way unless it be prevented. This is because the nature of the act is according to the nature of the agent; and hence as long as it has that nature, its acts will be in accordance with that nature; for every natural agent has a determinate being. Since, then, the Divine Being is undetermined, and contains in Himself the full perfection of being, it cannot be that He acts by a necessity of His nature, unless He were to cause something undetermined and indefinite in being: and that this is impossible has been already shown (7, 2). He does not, therefore, act by a necessity of His nature, but determined effects proceed from His own infinite perfection according to the determination of His will and intellect.

Thirdly, it is shown by the relation of effects to their cause....

Note: Aquinas' claim that each kind of thing is always naturally generated "in one and the same way" does not mean that that kind of thing is always generated according to one and only one fixed pathway. As a scholar, Aquinas would have been well aware that there are many different ways of generating each kind of chemical compound, depending on the order in which the ingredients are mixed. And as a student of St. Albert the Great (who is regarded as the re-discoverer of scientific botany in medieval Europe - see here and here), he would also have known that there are multiple ways of generating new plants - e.g. from a seed, or from a cutting, shoot or root, and that some plants reproduce both sexually and asexually. When Aquinas claims that each kind of thing is always naturally generated "in one and the same way," he is not talking about a sequence of steps along a pathway, but about the operation of a single agent acting on the right kind of matter, as we'll see in (c) and (d) below. Aquinas' key point was simply that whatever process is used to generate an entity of a certain kind, it needs to start with the right kind of stuff (matter) and a natural agent that is capable of generating a new form of that specific kind. (For instance, regardless of whether a plant reproduces sexually or asexually, it still needs to pass on genetic instructions, which are specific to that kind of plant, for generating the form of its offspring, as it develops, and these instructions require suitable matter to act upon.) Additionally, the process used must be a reliable process, which actually works all or most of the time: in other words, it must be replicable, and not one-off.

(c) According to Aquinas, each of the various kinds of things we see in the natural world can only be naturally generated from the right kind of matter. For instance, each kind or species of living thing is generated from its own determinate matter. Thus animals generated from the "seed" of their parents cannot be generated in any other way.

In his Summa Theologica I, q. 92 art. 2, reply to obj. 2 (Whether woman should have been made for man?), Aquinas declares that each species of thing has to be produced from its own determinate matter:

Reply to Objection 2. Matter is that from which something is made. Now created nature has a determinate principle; and since it is determined to one thing, it has also a determinate mode of proceeding. Wherefore from determinate matter it produces something in a determinate species.

Later on, in his Summa Theologica I, q. 92 art. 4 (Whether the woman was formed immediately by God?), Aquinas restates his conclusion even more clearly:

I answer that, As was said above (art. 2, ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man.

Note to the reader: Aquinas sometimes used the terms "seed" and "semen" in a much broader sense than we do today, as the following passage in his Summa Theologica I, q. 115 art. 2, Reply to Objection 3 makes clear:

Reply to Objection 3. The seed of the male is the active principle in the generation of an animal. But that can be called seed also which the female contributes as the passive principle. And thus the word "seed" covers both active and passive principles.

This explains the reference to "the human semen of man or woman" in the passage cited above.

Finally, in his Summa Contra Gentiles Book IV, chapter 45, paragraph 7 (That It Became Christ To Be Born Of a Virgin), Aquinas again alludes to the determinacy of natural causes, when he argues that although natural causes require a particular kind of matter in order to produce their effects, God, Who is the Author of Nature, is perfectly capable of using any kind of matter to produce any effect:

[7] ... Thus, then, by the divine power the matter taken from the woman alone can be reduced at the end of the generation to a disposition identical with that which matter has if taken simultaneously from the male and female. Hence, there will be no unlikeness by reason of diversity of matter between the body of Christ which was formed by the divine power out of matter taken from the mother alone, and our bodies which are formed by the natural power from matter, even though they are taken from both parents. Surely this is clear; the matter taken simultaneously from a man and a woman and that "slime of the earth" (Gen. 2:7) of which God formed the first man (very certainly a true man and like us in everything) differ more from one another than from the matter taken solely from the female from which the body of Christ was formed. Hence, the birth of Christ from the Virgin does not at all diminish either the truth of His humanity or His likeness to us. For, although a natural power requires a determined matter for the production of a determined effect therefrom, the divine power, the power able to produce all things from nothing, is not in its activity circumscribed within determinate matter.

(d) According to Aquinas, each kind of thing found in Nature can only be naturally generated by an agent of adequate power - i.e. one whose power is sufficient to generate the form characterizing that kind of thing.

In his Summa Contra Gentiles Book III chapter 102, paragraph 5 (That God alone works miracles), Aquinas makes it clear that different types of actualizations require different types of agents. Since each kind of thing we see in Nature is an actualization of matter, it follows that different kinds of agents are required to produce the various kinds of things we see in Nature. Moreover, certain kinds of creatures ("perfect animals") require a particular kind of agent to produce them - namely, "a definite kind of semen," from a male parent of the same species. Aquinas (following Aristotle) believed that in procreation, the father's semen did not contribute any material that went into the body of its offspring. Rather, it acted as a formative agent which kick-starts the process whereby the offspring acquires its proper form. Like his contemporaries, Aquinas also believed that some of the lower animals ("imperfect animals," as he calls them) could be spontaneously generated by the action of celestial bodies on decaying matter:

[5] Moreover, the subject in which an action goes on has a relation both to the agent that reduces it from potency to act and to the act to which it is reduced. Hence, just as a certain subject is in potency to some definite act, and not to merely any act, so also is it impossible for it to be reduced from potency to some definite act except by means of some definite agent. Indeed, a different kind of agent is required to reduce to different types of act. For instance, since air is potentially either fire or water, it is actually made into fire by one agent and into water by a different one. Likewise, it is clear that corporeal matter is not brought to the condition of perfect actuality by the sole power of a universal agent; rather, there must be a particular agent by which the influence of the universal power is limited to a definite effect. Of course, corporeal matter may be brought to less perfect actuality by universal power alone, without a particular agent. For example, perfect animals are not generated by celestial power alone, but require a definite kind of semen; however, for the generation of certain imperfect animals, celestial power by itself is enough, without semen.

Aquinas makes the same point in his Summa Theologica I, q. 71 a. 1, reply to obj. 1 (The Work of the Fifth Day), where he uses the example of animals being generated from seed to illustrate his point that Nature produces its effects by determinate means. Since Aquinas describes the seed as an "active principle" having "formative power" - in other words, a kind of agent - he must have meant that a special kind of agent is required to generate the forms of certain kinds of creatures:

Reply to Objection 1. It was laid down by Avicenna that animals of all kinds can be generated by various minglings of the elements, and naturally, without any kind of seed. This, however, seems repugnant to the fact that nature produces its effects by determinate means, and consequently, those things that are naturally generated from seed cannot be generated naturally in any other way. It ought, then, rather to be said that in the natural generation of all animals that are generated from seed, the active principle lies in the formative power of the seed, but that in the case of animals generated from putrefaction, the formative power of is the influence of the heavenly bodies.

The corollaries of Aquinas' arguments, and what they signify with regard to the neo-Darwinian theory of evolution

Corollary 1 (a scientific corollary): Neither life itself nor complex organisms could have originated as a result of "accidental" (i.e. chance-only) processes. If life arose naturally, it can only have been through law-governed processes.

Hence according to Aquinas, it is absurd to suggest that the various kinds of living things, or the biochemical or anatomical structures that characterize them, could have arisen naturally, but as a result of one-off or unrepeatable processes. Darwinists don't do this, of course; they're not that silly. Neo-Darwinian evolution is a "chance-plus-necessity" theory, with necessity [natural selection] playing the dominant role. However the proto-evolutionary account of origins proposed by the ancient Greek philosopher Empedocles (490-430 BC) was a "chance-only" account; therefore Aquinas rightly rejected it as absurd in his De Veritate q. 5 art. 2:

This was actually what Empedocles held. He asserted that it was by accident that the parts of animals came together in this way through friendship - and this was his explanation of an animal and of a frequent occurrence! This explanation, of course, is absurd, for those things that happen by chance, happen only rarely we know from experience, however, that harmony and usefulness are found in nature either at all times or at least for the most part. This cannot be the result of mere chance; it must be because an end is intended. (Note: Empedocles' enigmatic phrase "through friendship" is meant to signify some kind of affinity, defined in a loose sense. As he mentions parts of animals coming together, he is means structural affinity. Empedocles held that in the past, there were strange chimeras of various kinds of animals - e.g. half man-half ox chimeras, which later died out. Empedocles seems to have thought they died out not because they were unfit, but because their parts didn't fit together properly, while those animals that survived, managed to do so because their parts did. - VJT.)

Likewise, Aquinas would say that the supposition that life may have arisen on Earth as a result of some freakish occurrence is absurd. Even today, neo-Darwinists sometimes fall back on "chance" when attempting to account for the origin of life. For instance, in The Blind Watchmaker, Dr. Richard Dawkins says he expects the origin of life to be an exceedingly unlikely event, which only happened because the universe is so big and old - although he then hedges his bets by saying he would not be perturbed if life actually turned out to be very common.

Thus according to St. Thomas Aquinas, an accidental origin for life, or for any kind of living creature, is impossible. While God can work through chance events, particularly when exercising his Providence over individuals, He does not produce things according to their kind in this fashion.

The next corollary is of vital importance, as it pertains to the question of what kind of evidence it would take to persuade a Thomist - that is, a true disciple of Aquinas - that evolution is true.

Corollary 2 (an epistemic corollary): We shouldn't believe evolutionists' explanations of the origin of life or of various kinds of complex organisms, unless they can replicate them experimentally.

If the different kinds of things generated in Nature are all generated in a replicable fashion, as Aquinas asserts, then we should not believe scientists' claims that the various kinds of living things, or the biochemical or anatomical structures that characterize them, arose naturally, unless they can demonstrate a natural mechanism whereby this could have happened.

This is an extremely significant result: it entails that Thomists should be skeptical of neo-Darwinian evolution. Scientists have shown that species can evolve, and they have also amassed powerful evidence for universal common descent. However, they have failed to demonstrate the adequacy of any natural mechanism for generating all the different kinds of animals, plants, fungi and protists, as well as two domains of bacteria, from a primordial cell. Additionally, they have failed to demonstrate a process for generating the irreducibly complex structures we find in living things. Finally, they have failed to demonstrate a mechanism for generating the specified complexity that characterizes life itself: the origin of life remains as elusive as ever. Now, Aquinas insisted that "things that are done naturally are brought to their end by determinate means, and so they always happen in the same way, for nature is determined to one result" (Summa Contra Gentiles Book III chapter 85, paragraph 5). I conclude that in the absence of a demonstration of an efficacious and reliable mechanism for generating the first life, the diversity of life, and the irreducibly complex structures we find in living things, Aquinas would be unimpressed with the evidence for evolution, were he alive today.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz doesn't expressly contradict this Thomistic thesis, but the following quote suggests that he would disagree with it, as he suggests that even if we will never be able to replicate the processes that led to the formation of complex organisms, we can still be sure that they must have had a natural origin.

In his article for the journal This Rock, Professor Tkacz wrote:

The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

If the natural processes that gave rise to complex organisms are not replicable, then there are two possibilities: either these processes are not law-governed, i.e. they are freakish, accidental processes; or they are governed by laws which are too complex for human beings to figure out. The first supposition falls foul of Corollary 1 above (which states if complex organisms arose naturally, it can only have been through law-governed processes); while the second falls foul of Corollary 2 (which states that we shouldn't believe evolutionists' explanations of the origin of life or of various kinds of complex organisms, unless they can replicate them experimentally).

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The blue lobster - an example of a mutant. According to Aquinas, mutants could never give rise to new kinds of animals. Aquinas believed that new species could arise through hybridization of existing species, grafting or spontaneous generation, but not through mutation.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 8

"SMOKING GUN" Number 8:

GOD DESIGNED A WORLD OF FIXED KINDS, IN WHICH THE EVOLUTION OF NEW KINDS OF CREATURES AS A RESULT OF MUTATIONS IS IMPOSSIBLE. HYBRIDS BETWEEN EXISTING KINDS CAN GIVE RISE TO NEW KINDS, BUT ONE KIND OF CREATURE NEVER "CHANGES INTO" ANOTHER, OVER TIME. (ESSENTIALISM.)

Aquinas was an essentialist: he taught that God designed a world of fixed kinds, in which the evolution of new kinds as a result of mutations is impossible.

(a) According to Aquinas, living things belong to clearly defined kinds, which Aquinas also called "species." These kinds are fixed and unchangeable. They correspond to essences. As the evolutionary thinker Ernst Mayr has pointed out, Aristotle defined a "kind" or "species" according to typological criteria (such as anatomy, diet, habits and activities), rather than according to fertility in cross-breeding, as modern biologists do. (See Mayr, E. 1996. What is a Species and What is Not?, section 5. Originally published in Philosophy of Science, Vol. 63, (June 1996), pp. 262-277.)

(b) Aquinas drew a fundamental distinction between plants and animals that are naturally capable of reproducing themselves by their own power, and those that are spontaneously generated from dead or decaying matter by the power of the heavenly bodies. Aquinas also referred to animals that are naturally capable of reproducing themselves by their own power as "animals generated from seed."

(c) According to Aquinas, plants and animals that are "generated from seed" can only be naturally generated by parents of the same kind.

(d) According to Aquinas, plants and animals that are "generated from seed" always reproduce after their own kind: like begets like. Hence it is impossible for one kind of creature to evolve into another, by natural processes. New species may arise through hybridization of existing species, grafting or spontaneous generation, but not through mutation.

(e) According to Aquinas, God produced the first living creatures, according to their kinds.

NOTE: Aquinas, following Aristotle, equated kinds with species. I shall argue that he was wrong here, as species are not naturally fixed and unchangeable; nor are they clearly defined types. However, I shall argue in Part Two of my reply to Professor Tkacz that families of animals are indeed clear-cut types, and that what Aquinas referred to as a "kind" or "species," corresponds roughly to the scientific taxon of "family."

In Part Two of my reply to Professor Tkacz, I shall also argue that families are incapable of naturally evolving into new families, which explains why some families of animals from 400 million years ago still exist today (e.g. the family of Latimeriidae, which belong to the order of coelacanth fish). In other words, families are naturally fixed. Hence only the supernatural agency of God could have transformed ancestral families of animals into modern ones, in the absence of any other intelligent agents capable of doing the job.

Objection: someone might argue that the "like begets like" principle obviously implies that for Aquinas, kinds are biological species, rather than families as I have suggested.

Reply: For Aquinas, living things belong to clearly defined kinds, which he also called "species," following Aristotle. Moreover, these kinds are fixed and unchangeable. The evolutionary biologist Ernst Mayr distinguishes between two concepts of a species: the typological concept, which was prevalent until the mid-nineteenth century, and the biological concept, which developed in the second half of the nineteenth century. (See Mayr, E. 1996. What is a Species and What is Not? Originally published in Philosophy of Science, Vol. 63, (June 1996), pp. 262-277.) Aquinas, following Aristotle, defined a "kind" or "species" according to typological criteria, rather than according to fertility in cross-breeding, as modern biologists do. According to Mayr (see section 5 of hisessay), the word "species" traditionally denoted a class of objects, members of which shared certain defining properties, which did not change over time. For Aristotle, these properties related to a creature's diet, ecological niche, lifestyle and anatomy: "Animals differ from one another in their modes of subsistence, in their actions, in their habits, and in their parts" (On the History of Animals, Book I, Part 1, paragraph 8). Aristotle described about 500 kinds of animals in his History of Animals, and he correctly grasped that each biological kind had to be defined in terms of a multitude of traits, rather than a single trait.

Aristotle's great mistake, I shall argue, lay in his equating "species" with "indivisible groups" (see his On the Parts of Animals, Book I, Part 4, paragraph 3). For Aristotle, a species of animal is the smallest group of animals which is readily distinguishable from other groups on the basis of its anatomy, reproduction, habits, diet and lifestyle. I would argue that Aristotle's classification of "species" is too fine-grained, and that it is also internally inconsistent: the smallest group of animals which is readily distinguishable from other groups on the basis of its anatomy, reproduction, habits, diet and lifestyle (namely, a species) may not necessarily remain naturally fixed over time (as an Aristotelian essence has to be). Hence species do not qualify as genuine Aristotelian types. That's why I would argue that overall, the scientific taxon "family" better fits the Aristotelian notion of a fixed essence, or type, than the biological concept of a species. (I will argue in Part Two that a family is indeed naturally fixed over time.)

Unfortunately, Aristotle's mistake also influenced Aquinas. For instance, both Aristotle (see his History of Animals Book I, chapter 6, paragraph 7) and Aquinas (see his Summa Theologica I, q. 73, art. 1, reply to objection 3) believed that horses and donkeys belonged to sharply defined kinds which do not change over time, despite their known ability to inter-breed, generating a new hybrid species (mules). However, we now know that they were both mistaken on this point: recent research indicates that horses and donkeys diverged from a common ancestor about 2.4 million years ago, as a result of entirely natural processes which can be readily identified from their genes.

Scientists now know that over the short term, creatures do indeed reproduce after their species, but that over the long term, species evolve naturally. Speciation has been observed. (See Has speciation (the splitting of one species into two) ever been observed in nature? by David Bailey, Observed instances of speciation by Joseph Boxhorn and Some More Observed Speciation Events by Chris Stassen et al.) However, from the fact that species evolve over time, we should not conclude that they are infinitely malleable, or that essentialism is false. On the contrary, we now have good scientific evidence that evolution has limits, and that creatures can only evolve within naturally constrained boundaries. Professor Michael Behe has catalogued this evidence in The Edge of Evolution. I shall argue in Part Two that the scientific taxon "family" roughly corresponds to this boundary, and that there are indeed sharp discontinuities between different families belonging to the same taxonomic order. If we re-define "kind" as "family," Aquinas' essentialism remains as valid as ever, in the 21st century.

WHERE DOES AQUINAS SAY ALL THIS?

Let's examine (a), (b), (c), (d) and (e) in turn.

(a) According to Aquinas, living things belong to clearly defined kinds, which Aquinas also called "species." These kinds are fixed and unchangeable. They correspond to essences.

Where Aquinas says this:

In his History of Animals, Aristotle writes:

"Animals differ from one another in their modes of subsistence, in their actions, in their habits, and in their parts." (On the History of Animals, Book I, Part 1, paragraph 8).

Here it can readily be seen that Aristotle defined a "kind" or "species" according to typological criteria (such as anatomy, diet, habits and activities), rather than according to fertility in cross-breeding, as modern biologists do.

Aquinas asserted the fixity and unchangeability of species in his Summa Theologica I, q. 98 art. 12, where he addresses the question of whether human beings would still have generated offspring in the state of innocence (the Garden of Eden). In this passage, he asserts clearly that the "direct purpose of nature" is the preservation of that "which is invariable and perpetual." The good of individual creatures, which are mortal, is therefore subordinate to that of species, which are "everlasting and permanent." Insofar as human beings have an immortal soul, their individual good is included within Nature's principal purpose; but insofar as their bodies are naturally corruptible, it is fitting that they should generate themselves, for the good of the human species:

I answer that, In the state of innocence there would have been generation of offspring for the multiplication of the human race; otherwise man's sin would have been very necessary, for such a great blessing to be its result. We must, therefore, observe that man, by his nature, is established, as it were, midway between corruptible and incorruptible creatures, his soul being naturally incorruptible, while his body is naturally corruptible. We must also observe that nature's purpose appears to be different as regards corruptible and incorruptible things. For that seems to be the direct purpose of nature, which is invariable and perpetual; while what is only for a time is seemingly not the chief purpose of nature, but as it were, subordinate to something else; otherwise, when it ceased to exist, nature's purpose would become void.

Therefore, since in things corruptible none is everlasting and permanent except the species, it follows that the chief purpose of nature is the good of the species; for the preservation of which natural generation is ordained. On the other hand, incorruptible substances survive, not only in the species, but also in the individual; wherefore even the individuals are included in the chief purpose of nature.

Hence it belongs to man to beget offspring, on the part of the naturally corruptible body. But on the part of the soul, which is incorruptible, it is fitting that the multitude of individuals should be the direct purpose of nature, or rather of the Author of nature, Who alone is the Creator of the human soul. Wherefore, to provide for the multiplication of the human race, He established the begetting of offspring even in the state of innocence.

Aquinas is even clearer about the perpetuity of species in his Quaestiones Disputatae De Potentia Dei (Disputed Questions on the Power of God), Question V, article IX, where he discusses the question of whether plants, animals and minerals will remain after the end of the world. Aquinas' answer is that apart from human beings, composite beings (such as plants and animals) will not survive the end of the world, when the heavenly bodies stop moving, "since the very souls of animals and plants are wholly subject to the influence of the heavenly bodies." In defending this view, Aquinas has to rebut the objection that since Nature's aim cannot be frustrated, and Nature aims at assuring the perpetuity of species, the various species of plants and animals must last forever. Aquinas' response is that in the order of Nature, the perpetuity of species is guaranteed by the movements of the heavenly bodies. As long as they keep moving, each species will continue to exist; but when the heavens stop moving, plants and animals will cease to exist.

[Objection] 3. The intention of nature cannot be frustrated, because nature's intention consists in its being guided to its end by God. Now by generation and corruption nature intends to assure the perpetuity of the species. Therefore, unless these things be preserved in their species, nature's intention will be abortive: and this is impossible, as stated.

Reply to the Third Objection. Nature's intention is to perpetuate the species as long as the heavenly movement continues whereby that perpetuity is assured.

Finally, in the same passage, Aquinas equates species with universals, or essences, when he considers the objection that if all the individuals of a species were to perish, the universal corresponding to it would also cease to be; and yet universals are everlasting:

[Objection] 16. The universal is everlasting: yet it does not exist save in individuals. Therefore it would seem that the individuals of every universal will last for ever: and consequently dumb animals, plants and minerals will always exist.

In his reply, Aquinas distinguishes three senses in which universals can be described as everlasting, after a fashion - the most important of which is that they will always exist as ideas in the mind of God.

(b) Aquinas drew a fundamental distinction between plants and animals that are naturally capable of reproducing themselves by their own power, and those that are spontaneously generated from dead or decaying matter by the power of the heavenly bodies. Aquinas also referred to animals that are naturally capable of reproducing themselves by their own power as "animals generated from seed."

Where Aquinas says this:

Aquinas' biology was heavily influenced by that of Aristotle, who distinguished between plants and animals that were generated from seed, and those that were spontaneously generated, in his History of Animals Book V, part 1 (see paragraph 3). Aristotle also taught that animals generated from seed reproduce according to their kind:

Now there is one property that animals are found to have in common with plants. For some plants are generated from the seed of plants, whilst other plants are self-generated through the formation of some elemental principle similar to a seed; and of these latter plants some derive their nutriment from the ground, whilst others grow inside other plants, as is mentioned, by the way, in my treatise on Botany. So with animals, some spring from parent animals according to their kind, whilst others grow spontaneously and not from kindred stock; and of these instances of spontaneous generation some come from putrefying earth or vegetable matter, as is the case with a number of insects, while others are spontaneously generated in the inside of animals out of the secretions of their several organs.

Aquinas makes the same distinction in his Summa Theologica I, q. 92 art. 1 (Whether the woman should have been made in the first production of things), Aquinas makes it clear that he draws a sharp dividing line between animals which are capable of reproducing themselves and those which are not. The latter "do not possess in themselves the power of generation, but are generated by some other specific agent," and "not from seed":

I answer that, It was necessary for woman to be made, as the Scripture says, as a "helper" to man; not, indeed, as a helpmate in other works, as some say, since man can be more efficiently helped by another man in other works; but as a helper in the work of generation. This can be made clear if we observe the mode of generation carried out in various living things. Some living things do not possess in themselves the power of generation, but are generated by some other specific agent, such as some plants and animals by the influence of the heavenly bodies, from some fitting matter and not from seed: others possess the active and passive generative power together; as we see in plants which are generated from seed; for the noblest vital function in plants is generation. Wherefore we observe that in these the active power of generation invariably accompanies the passive power. Among perfect animals the active power of generation belongs to the male sex, and the passive power to the female. And as among animals there is a vital operation nobler than generation, to which their life is principally directed; therefore the male sex is not found in continual union with the female in perfect animals, but only at the time of coition; so that we may consider that by this means the male and female are one, as in plants they are always united; although in some cases one of them preponderates, and in some the other. But man is yet further ordered to a still nobler vital action, and that is intellectual operation. Therefore there was greater reason for the distinction of these two forces in man; so that the female should be produced separately from the male; although they are carnally united for generation. Therefore directly after the formation of woman, it was said: "And they shall be two in one flesh" (Genesis 2:24).

In the above passage, Aquinas equates plants and animals that possess the power of generation in their own right with plants and animals that are "generated from seed." I would like to note in passing that this is an empirical assertion, which is logically independent of the philosophical distinction drawn by Aquinas between plants and animals that possess the power of generation in their own right and those that do not. The term "seed" refers to the active principle of generation. Aquinas, following the biology of Aristotle, held that the active principle of generation came from the father alone. In Aristotle's account of reproduction, the female's role was a passive one: she supplied the raw material for the developing embryo, while the male's role was that of a form-building agent that fashioned this material, by kick-starting the development of the embryo. Michael Nolan (The Defective Male: What Aquinas Really Said, New Blackfriars, vol. 75, Issue 880, pp. 156-166) elucidates what Aristotle meant by the terms "active" and "passive":

Aristotle does indeed talk of the male element as active and the female as passive, but only in the sense in which an enzyme is active and the process it facilitates is passive. "The action of the male in setting the female's secretion in the uterus is similar to that of rennet upon milk." De Generatione Animalium. Bk 2. c. 4, 739b22. (See footnote 9, p. 164.)

For Aquinas, animals "generated from seed" are those which: (i) are generated via sexual reproduction, (ii) are formed as a result of a process initiated by the male parent's "seed", which is the active principle of generation, and (iii) breed true to type (as we shall see in part (d) below).

Scientists now know that Aquinas' definition of animals "generated from seed" applies to the vast majority of animals, although his second condition would have to be modified to include reference to the active role played by both the female and the male, in generating the form of their offspring.

Let's look at the first condition. Almost all animals - including most insects - reproduce sexually. Of course, there are exceptions: a few types of insects (e.g. aphids and the cape bee) alternate between sexual and asexual reproduction, as well as a few species of fish, amphibians and reptiles - and among birds, the turkey. Rotifers (commonly called wheel animals) are only capable of asexual reproduction. Budding is an asexual mode of reproduction observed in corals, jellyfish, parasitic animals such as tapeworms and many echinoderms; and fragmentation is observed in certain tiny worms. Nevertheless, for most animals, sexual reproduction is the norm.

Aquinas' second condition is true insofar as the "seed" of the male is an active principle of generation. However, scientists now know that in sexual reproduction, both parents (and not just the male) pass on instructions for the formation of the embryo, via their genes. Aquinas could not have known that - a fact for which he can hardly be blamed, as the first human ovum was not observed by scientists until as late as 1827, and the structure of DNA was not discovered until 1953. In any case, the Aristotelian view that the male alone plays the active role in reproduction can no longer be sustained. In sexual reproduction, both sexes play an active role in determining the form of their offspring.

Aquinas' third condition is also satisfied. The genetic mechanism of heredity, which makes use of DNA, ensures that animals breed true to type.

I remarked earlier that for Aquinas, the fundamental division in living things is between those that "possess in themselves the power of generation" in an active sense, and those that do not. Living things in the latter category cannot generate themselves, so they have to be spontaneously generated. However, scientists now know that there are no animals which are generated spontaneously, from dead or decaying matter. What's more, even animals which reproduce asexually (e.g. as a result of parthenogenesis, apomixis or fragmentation) are still generated from some parent animal, which transmits to its offspring not only material from its own body, but also coded instructions in its genes, which direct and control the formation of the newly generated animal. Thus modern scientists would say that all animals "possess in themselves the power of generation" (as Aquinas puts it), in an active as well as a passive sense.

(c) According to Aquinas, plants and animals that are "generated from seed" can only be naturally generated by parents of the same kind. Animals that are "generated from seed" can only be naturally generated from the right kind of matter (which had to be supplied by a mother of the same species, according to the Aristotelian biology adopted by Aquinas) and the right kind of form-building agent (the "seed" supplied by a male parent of the same species), which (Aquinas believed) kick-starts the development of the embryo. Thus a baby hippopotamus can only be naturally generated from hippo parents, and not from any other kind of animal. This is a corollary of Aquinas' hyper-uniformitarian principle (see "Smoking Gun" number 7).

Where Aquinas says this:

It is important for the reader to understand that Aquinas used the terms "seed" and "semen" in a much broader sense than we do today, as the following passage in his Summa Theologica I, q. 115 art. 2, Reply to Objection 3makes clear:

Reply to Objection 3. The seed of the male is the active principle in the generation of an animal. But that can be called seed also which the female contributes as the passive principle. And thus the word "seed" covers both active and passive principles.

For Aquinas, there are two reasons why plants and animals that are "generated from seed" can only be naturally generated by parents of the same kind. First, each and every kind (or species) of creature has to be generated from the right kind of matter. For animals generated from seed, that matter has to come from a parent of the same species. Second, each and every species has to be generated from the right kind of form-producing agent. For animals generated from seed, that agent is semen from a male parent of the same species.

Aquinas affirms that each and every kind (or species) of creature has to be generated from the right kind of matter, in his discussion of how God made Eve, in his Summa Theologica I, q. 92 art. 2, reply to obj. 2 (Whether woman should have been made for man?). First of all, he argues that each species has to be produced from a special kind of matter:

Reply to Objection 2. Matter is that from which something is made. Now created nature has a determinate principle; and since it is determined to one thing, it has also a determinate mode of proceeding. Wherefore from determinate matter it produces something in a determinate species. On the other hand, the Divine Power, being infinite, can produce things of the same species out of any matter, such as a man from the slime of the earth, and a woman from out of man.

Next, in his Summa Theologica I, q. 92 art. 4 (Whether the woman was formed immediately by God?), Aquinas applies his principle that "the natural generation of every species is from some determinate matter" to the generation of human beings. Aquinas argues that a human being can only be naturally generated from matter derived from another human being:

I answer that, As was said above (art. 2, ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man.

Aquinas' cryptic reference to the "semen of man or woman" is due to the fact that he sometimes used the term "seed" (or "semen") to refer to the matter out of which the embryo was formed, as well as the formative agent. As he put it in his Summa Theologica, I, q. 115 art. 2, Reply to Objection 3:

Reply to Objection 3. The seed of the male is the active principle in the generation of an animal. But that can be called seed also which the female contributes as the passive principle. And thus the word "seed" covers both active and passive principles.

Another place where Aquinas teaches that living things which are naturally generated from seed have to be generated from parents of the same kind is in his Commentary on Aristotle's Physics, Book II, lecture 7, Paragraphs 203-204 (Lecture 7: Different Opinions about Fortune and Chance, the Hidden Causes), Aquinas attacks Democritus' theory that chance governed everything, on the grounds that it was utterly unable to account for the simple fact that each kind of living thing is generated from a particular kind of seed:

203. ... He [Aristotle] says, therefore first, that some have said that chance is the cause of the heavens and all the parts of the world. And they said that the revolution of the world, and the movement of the stars distinguishing and constituting the whole universe below according to this order, is by chance. This seems to be the opinion of Democritus, who says that the heavens and the whole world are constituted by chance through the movement of atoms which are per se mobile.

204. Next where he [Aristotle] says, 'This statement might ...' (196 a 28), he disproves this position with two arguments.

The first argument is that it would seem to be worthy of great wonder that animals and plants are not from fortune but from intellect or nature or some other determinate cause. For it is clear that a thing is not generated from any seed whatsoever, but man from a determinate seed, and the olive from a determinate seed. And since these inferior things do not come to be by fortune, it is worthy of wonder that the heavens and those things which are more divine among the sensible things obvious to us, e.g. the sempiternal parts of the world, are by chance, and should not have any determinate cause, as do animals and plants. And if this is true, it would have been worthwhile to insist and to give a reason why this is so. But the ancients failed to do this.

Aquinas is even clearer in his discussion of the fifth day of Genesis 1, where he expressly declares in his Summa Theologica I, q. 71 a. 1, reply to obj. 1 (The Work of the Fifth Day), that animals that are "naturally generated from seed" cannot be naturally generated in any other way:

Objection 1. It would seem that this work is not fittingly described. For the waters produce that which the power of water suffices to produce. But the power of water does not suffice for the production of every kind of fishes and birds since we find that many of them are generated from seed. Therefore the words, "Let the waters bring forth the creeping creature having life, and the fowl that may fly over the earth," do not fittingly describe this work.

Reply to Objection 1. It was laid down by Avicenna that animals of all kinds can be generated by various minglings of the elements, and naturally, without any kind of seed. This, however, seems repugnant to the fact that nature produces its effects by determinate means, and consequently, those things that are naturally generated from seed cannot be generated naturally in any other way. It ought, then, rather to be said that in the natural generation of all animals that are generated from seed, the active principle lies in the formative power of the seed, but that in the case of animals generated from putrefaction, the formative power of is the influence of the heavenly bodies. The material principle, however, in the generation of either kind of animals, is either some element, or something compounded of the elements. But at the first beginning of the world the active principle was the Word of God, which produced animals from material elements, either in act, as some holy writers say, or virtually, as Augustine teaches. Not as though the power possessed by water or earth of producing all animals resides in the earth and the water themselves, as Avicenna held, but in the power originally given to the elements of producing them from elemental matter by the power of seed or the influence of the stars.

Finally, in his Summa Contra Gentiles Book III, chapter 102, paragraph 5 (That God Alone Works Miracles), Aquinas writes that some animals, which he calls "perfect animals," have to be generated from a "definite kind of semen" coming from a specific kind of agent:

[5] Moreover, the subject in which an action goes on has a relation both to the agent that reduces it from potency to act and to the act to which it is reduced. Hence, just as a certain subject is in potency to some definite act, and not to merely any act, so also is it impossible for it to be reduced from potency to some definite act except by means of some definite agent. Indeed, a different kind of agent is required to reduce to different types of act. For instance, since air is potentially either fire or water, it is actually made into fire by one agent and into water by a different one. Likewise, it is clear that corporeal matter is not brought to the condition of perfect actuality by the sole power of a universal agent; rather, there must be a particular agent by which the influence of the universal power is limited to a definite effect. Of course, corporeal matter may be brought to less perfect actuality by universal power alone, without a particular agent. For example, perfect animals are not generated by celestial power alone, but require a definite kind of semen; however, for the generation of certain imperfect animals, celestial power by itself is enough, without semen. So, if the effects that are accomplished in these lower bodies are naturally capable of being done by superior universal causes without the working of particular lower causes, such accomplishment is not miraculous. Thus, it is not miraculous for animals to be originated from putrefaction, independently of semen. But, if they do not naturally come about through superior causes alone, then particular lower causes are needed for their development. Now, when some effect is produced by a higher cause through the mediation of proper principles, there is no miracle. Therefore, no miracles can be worked in any way by the power of the higher creatures.

Note: The term "celestial power" refers to the power of the heavenly bodies, which were popularly believed in the Middle Ages to play a vital role in reproduction, even for the higher animals (or "perfect animals," as Aquinas called them). Aquinas believed that the heavenly bodies were able to generate the lower animals, but not the higher ones, by acting on dead or decaying matter.

(d) According to Aquinas, animals always reproduce after their own kind: like begets like. Hence it is impossible for one kind of creature to evolve into another, by natural processes. New species may arise through hybridization of existing species, grafting or spontaneous generation, but not through mutation.

Where Aquinas says this:

Aquinas affirms the generation of like from like in his Summa Theologica I, q. 72 a. 1, reply to obj. 3, where he discusses the work of the sixth day of Genesis 1:

Objection 3. Further, as animals belong to a determinate genus and species, so also does man. But in the making of man nothing is said of his genus and species, and therefore nothing ought to have been said about them in the production of other animals, whereas it is said "according to its genus" and "in its species."

Reply to Objection 3. In other animals, and in plants, mention is made of genus and species, to denote the generation of like from like. But it was unnecessary to do so in the case of man, as what had already been said of other creatures might be understood of him. Again, animals and plants may be said to be produced according to their kinds, to signify their remoteness from the Divine image and likeness, whereas man is said to be made "to the image and likeness of God."

In his Commentary on Aristotle's Physics, Book II, lecture 7, paragraph 204 Different opinions about fortune and chance, the hidden causes), where he writes:

For it is clear that a thing is not generated from any seed whatsoever, but man from a determinate seed, and the olive from a determinate seed.

Aquinas discusses the appearance of new species in his Summa Theologica I, q. 73 art. 1, where he addresses the question of whether the completion of the Divine works ought to be ascribed to the seventh day in Genesis 1. Aquinas anticipates the objection that "many things were made after the seventh day, as the production of many individual beings, and even of certain new species that are frequently appearing, especially in the case of animals generated from putrefaction. Also, God creates daily new souls. Again, the work of the Incarnation was a new work... Moreover, all things will be made new when the saints are glorified..."

In his response, Aquinas allows that new species might appear as a result of spontaneous generation, which he accepted as a fact, like nearly all his contemporaries. He was also aware of hybridization: he remarks that a mule can arise from a horse mating with an ass. And he must have been aware of the claim made by his teacher, St. Albert the Great, that new species could arise by grafting. Aquinas' point, however, was that in all these cases, nothing fundamentally new appeared: everything pre-existed in the causes. Hence "species, also, that are new, if any such appear, existed beforehand in various active powers."

Reply to Objection 3. Nothing entirely new was afterwards made by God, but all things subsequently made had in a sense been made before in the work of the six days. Some things, indeed, had a previous experience materially, as the rib from the side of Adam out of which God formed Eve; whilst others existed not only in matter but also in their causes, as those individual creatures that are now generated existed in the first of their kind. Species, also, that are new, if any such appear, existed beforehand in various active powers; so that animals, and perhaps even new species of animals, are produced by putrefaction by the power which the stars and elements received at the beginning. Again, animals of new kinds arise occasionally from the connection of individuals belonging to different species, as the mule is the offspring of an ass and a mare; but even these existed previously in their causes, in the works of the six days. Some also existed beforehand by way of similitude, as the souls now created. And the work of the Incarnation itself was thus foreshadowed, for as we read (Philippians 2:7), The Son of God "was made in the likeness of men." And again, the glory that is spiritual was anticipated in the angels by way of similitude; and that of the body in the heaven, especially the empyrean. Hence it is written (Ecclesiastes 1:10), "Nothing under the sun is new, for it hath already gone before, in the ages that were before us."

From the foregoing, we can see that Aquinas believed that sexually reproducing animals could occasionally give rise to new hybrid species, but that nothing fundamentally new ever appeared in Nature. Mules are hybrids, derived from two original species (horses and donkeys) which Aquinas believed had been made by God in the work of the six days of Genesis 1: "Again, animals of new kinds arise occasionally from the connection of individuals belonging to different species, as the mule is the offspring of an ass and a mare; but even these existed previously in their causes, in the works of the six days" (Summa Theologica I, q. 73, art. 1, Reply to Objection 3).

Moreover, Aquinas also expressly taught that existing species did not evolve into new species over time. He believed that the original species of plants and animals had been created in the works of the six days, and that they would last until the end of time, when the movement of the heavens will stop (see his Quaestiones Disputatae De Potentia Dei (Disputed Questions on the Power of God), Question V, article IX).

Additionally, in his Summa Theologica I, q. 118, art. 3, reply to objection 1, Aquinas writes that all the species created by God were created in the first works: "God is said to have rested on the seventh day, not from all work, since we read (John 5:17): "My Father worketh until now"; but from the creation of any new genera and species, which may not have already existed in the first works."

Further confirmation of Aquinas' views on the fixity of species is given in the following paragraph, where he writes: "Something can be added every day to the perfection of the universe, as to the number of individuals, but not as to the number of species" ( Summa Theologica I, q. 118, art. 3, reply to objection 2).

Finally, given Aquinas' assertion (see above) that living things reproduce according to their kind (Summa Theologica I, q. 72 a. 1, reply to obj. 3), there could be no question of an existing species evolving into a new species as a result of mutations accumulating over the course of time. That would contradict his essentialism.

(e) According to Aquinas, God produced the first living creatures, according to their kinds.

Where Aquinas says this:

In his Summa Contra Gentiles Book II chapter 43, paragraphs 9 and 10 (That the distinction of things is not caused by some secondary agent introducing forms into matter):

[9] Furthermore, since every agent produces its like, the effect obtains its form from that reality to which it is made like through the form acquired by it; the material house acquires its form from the art which is the likeness of the house present in the mind. But all things are like God, who is pure act, so far as they have forms, through which they become actual; and so far as they desire forms, they are said to desire the divine likeness. It is therefore absurd to say that the formation of things is the work of anything other than God the Creator of all.

[10] So it is that in order to cast out this error, Moses, after saying that God "in the beginning created heaven and earth" (Gen. 1:1), went on to explain how God distinguished all things by forming them in their proper species. And St. Paul says that "in Christ were all things created in heaven and on earth, visible and invisible" (Col. 1:16).

Where Professor Tkacz contradicts St. Thomas:

In his original talk given to the Gonzaga Socratic Club, Professor Tkacz said:

It would seem that Intelligent Design Theory is grounded on the Cosmogonical Fallacy. Many who oppose the standard Darwinian account of biological evolution identify creation with divine intervention into nature. This is why many are so concerned with discontinuities in nature, such as discontinuities in the fossil record: they see in them evidence of divine action in the world, on the grounds that such discontinuities could only be explained by direct divine action.

From the foregoing, it would appear that Professor Tkacz does not believe that there are sharp discontinuities between the different "kinds" of living things; for if such discontinuities existed, then Darwinian evolution, which Tkacz regards as a legitimate scientific theory, would be impossible.

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Tintoretto, "Creation of the Animals," c. 1550. Gallerie dell'Accademia, Venice.
According to Aquinas, an animal that reproduces sexually and breeds true to type (i.e. an animal that is "naturally generated from seed") can only be naturally generated from parents of the same kind. Aquinas argues that the first such animals must therefore have been produced by God.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 9

"SMOKING GUN" Number 9:

THE FIRST ANIMALS THAT WERE CAPABLE OF REPRODUCING ACCORDING TO THEIR KIND MUST HAVE BEEN IMMEDIATELY PRODUCED BY GOD AND GOD ALONE. (SUPERNATURAL PRODUCTION OF THE FIRST ANIMALS.)

According to Aquinas, all animals that are naturally "generated from seed" must have been immediately produced by God alone, in the beginning.

Aquinas taught that God must have immediately produced the very first animals that are naturally "generated from seed," according to their kind. There was no natural way in which these animals could have been produced, as their forms could only have been naturally generated by a male parent of the same kind, and the matter out of which their bodies were made could only have come from a female parent of the same kind (see "Smoking Gun" Number 8 above). Thus a baby hippopotamus can only be naturally generated from hippo parents, and not from any other kind of animal. Hence if the various kinds of animals living on Earth had a beginning at some point in time, then we can be sure that the immediate action of God was responsible, and not some natural process, such as Darwinian evolution.

Where Aquinas says this:

Before we can appreciate Aquinas' argument, we need to understand what Aquinas and his medieval contemporaries believed regarding spontaneous generation.

Background: what people in the Middle Ages believed regarding spontaneous generation

I'd like to quote from the following article by I. M. L. Donaldson, entitled Redi's denial of spontaneous generation in insects, in the Journal of the Royal College of Physicians of Edinburgh 2010; 40:185-6, doi:10.4997/JRCPE.2010.218. The bold type below is mine.

Part of the legacy of the ancient to the early modern world was the belief that living creatures were generated in two distinct ways. The first, generatio univoca, was from parents of the same species. But another type of generation was believed to be common, especially for lower, or at least smaller, animals - 'spontaneous generation', generatio aequivoca, in which living things originated from non-living materials such as mud, slime or rotting vegetable or animal matter. Once generated, these creatures might breed by sexual reproduction, but were claimed by some authorities, following Aristotle, not to breed true but to give rise to a different species. For Aristotle, 'the issue of copulation in lice is nits; in flies, grubs; in fleas, grubs egg-like in shape' (Historia animalium. Trans. D. A. W. Thompson. Oxford: Clarendon Press; 1910. Book 5, chapter 1). A particularly common source of 'spontaneously' generated life were the grubs or maggots that appear in rotting animal matter and give rise to flies. The appearance of maggots apparently spontaneously, and of flies from these maggots, seemed to confirm both the occurrence of generatio aequivoca and that its progeny did not breed true. The existence of spontaneous generation was accepted, apparently without question, until the second half of the seventeenth century, and the belief persisted in one form or another until well into the nineteenth.

Aristotle's views on spontaneous generation, which influenced Aquinas, are described in greater detail in an article by Dr. Eugene McCartney, entitled Spontaneous Generation and Kindred Notions in Antiquity (in Transactions of the American Philological Association, Vol. 51 (1920), pp. 101-115).

Aquinas' argument that animals "generated from seed" must originally have been produced by God

Aquinas sets out his argument in two passages in his writings. One of these passages is in his Summa Theologica, and the other is in his Summa Contra Gentiles. The former passage is shorter, so we'll examine it first.

The first version of Aquinas' argument

The first passage where Aquinas argued that perfect animals must have been produced immediately by God can be found in his Summa Theologica I, q. 71 art. 1, Reply to Objection 1 (The work of the fifth day). The key point of Aquinas' argument here is that if certain kinds of animals could only be generated by two parents of the same kind breeding true to type, and if these animals had a beginning at some point in time, then there was no natural way to generate the first animals of these kinds, as they obviously didn't have any parents. Aquinas concludes that these kinds of animals must have been originally produced through the immediate action of God alone.

Two centuries before Aquinas, the philosopher Avicenna (c. 980-1037) had maintained that animals of all kinds - even the higher animals - could be generated spontaneously from dead or decaying matter. Aquinas argued against Avicenna's assertion in his Summa Theologica I, q. 71 art. 1, Reply to Objection 1 (The Work of the Fifth Day), where he attempts to show that animals that are naturally generated from seed could not be produced in this way:

Reply to Objection 1. It was laid down by Avicenna that animals of all kinds can be generated by various minglings of the elements, and naturally, without any kind of seed. This, however, seems repugnant to the fact that nature produces its effects by determinate means, and consequently, those things that are naturally generated from seed cannot be generated naturally in any other way.

Aquinas continues:

It ought, then, rather to be said that in the natural generation of all animals that are generated from seed, the active principle lies in the formative power of the seed, but that in the case of animals generated from putrefaction, the formative power is the influence of the heavenly bodies. The material principle, however, in the generation of either kind of animals, is either some element, or something compounded of the elements.

The forms of animals that are "generated from seed" require parental input. Aquinas, following the Aristotelian biology of his day, thought that the father's "seed" alone contained the active principle, or "formative power." Of course, we now know that both parents pass on instructions for the formation of the embryo, via their genes, and that the global arrangement of the mother's egg also contains three-dimensional information required for the embryo's formation. However, Aquinas could not have known this - a fact for which he can hardly be blamed, as the first human ovum was not observed by scientists until as late as 1827. In any case, it makes no real difference to Aquinas' argument which parent is responsible for generating the embryo's form; the point is that a parent of the same species is required.

Aquinas defined the matter out of which animals were generated as the raw material. This matter wasn't just any old stuff: it was highly specific. In his Summa Theologica I, q. 92, art. 4 (Whether the woman was formed immediately by God?), Aquinas explained that determinate matter is required for the natural generation of each and every species:

I answer that, As was said above (2, ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man.

But if perfect animals could only be naturally generated from parents of the same kind, then the first perfect animals must have been produced supernaturally, by an act of God. This is precisely what Aquinas concludes at the end of his reply to Avicenna's argument, in his Summa Theologica I, q. 71 art. 1, Reply to Objection 1 (The work of the fifth day):

But at the first beginning of the world the active principle was the Word of God, which produced animals from material elements, either in act, as some holy writers say, or virtually, as Augustine teaches. Not as though the power possessed by water or earth of producing all animals resides in the earth and the water themselves, as Avicenna held, but in the power originally given to the elements of producing them from elemental matter by the power of seed or the influence of the stars.

Here, Aquinas states that the very first animals which are "generated from seed" must have been produced by the Word of God, working on material elements. Aquinas asserts this conclusion even more clearly at the end of his second argument, which we'll discuss below.

The reader may be wondering: what does "virtually" mean, in the passage above, where Aquinas says that the Word of God produced the animals "in act" or "virtually"? Aquinas believed that God may have produced animals in one of two ways. First, He may have produced animals "in act" - i.e. fully-fledged perfect animals, complete with all their parts. Alternatively, Aquinas thought that God may have produced the first animals "virtually" - i.e. as germinal "seeds" (rationes seminales, or literally "seminal reasons") that later grew into mature animals. (This was St. Augustine's theory, and I'll have more to say about it in a future post. All I'll say for now is that St. Augustine expressly taught that these germinal seeds (rationes seminales) were produced by God, according to their kind, and that each "seed" grew into an individual animal, and nothing more. As Fr. Frederick Copleston S.J. explains in his monumental work, A History of Philosophy. Volume 2: Augustine to Scotus (Burns and Oates, Tunbridge Wells, 1950; paperback edition 1999, p. 77):

... God did indeed create all things together in the beginning, but that he did not create them all in the same condition: many things, all plants, fishes, birds, animals, and man himself, He created invisibly, latently, potentially, in germ, in their rationes seminales...Each species then, with all its future developments and particular members, was created at the beginning in the appropriate seminal reason.

Hence there can be no question of St. Augustine supporting some version of evolution, as some writers have falsely alleged.

Anyway, the key point is that it was God who directly produced the forms of the first perfect animals, regardless of whether He produced them as mature adults or in an immature, latent form.

It should be noted that Aquinas' argument works equally well, regardless of whether the world is very old or very young. Basically, Aquinas' argument is an essentialist argument, based on his stated premise that "nature produces its effects by determinate means." We examined this premise when looking at Aquinas' "Smoking Guns," numbers 7 and 8 above. For animals that were "naturally generated from seed," the "determinate means" refers to generation by parents of the same kind.

The second version of Aquinas' argument

The second passage in which Aquinas sets out his argument showing that animals which are naturally generated by two parents must have been immediately produced by God alone, in the beginning, is in his Summa Contra Gentiles Book II chapter 43, paragraph 6 (That The Distinction of Things Is Not Caused By Some Secondary Agent Introducing Diverse Forms Into Matter). Here he argues that changes occurring in Nature can ultimately be traced back to the movements of the heavenly bodies, but that the movements of these bodies were incapable of generating new animals by themselves, except for animals that don't need parents. (Aquinas thought some simple animals didn't.) The heavenly bodies are only capable of producing animals that are naturally generated by their parents if two extra things (contributed by the parents) are present: the right kind of form-producing agent, and the right kind of stuff, or material. (See "Smoking Guns" number 7 and number 8 above.) However, Aquinas (as a Christian) believed that the world had a beginning, so this raised the question: if certain kinds of animals require parents, where did the first animals of these kinds come from? Aquinas' answer was that these kinds of animals must have been originally produced by God.

The key premises here are that the movements of the heavenly bodies cause all natural changes occurring on Earth, and that the movements of the heavenly bodies cannot explain the origin of animals that are naturally "generated from seed." Let us examine each of these in turn.

(a) Why Aristotle and Aquinas believed that the movements of the heavenly bodies caused all natural changes occurring on Earth

Aquinas' belief that all changes occurring on Earth can be ultimately traced back to the movements of the heavenly bodies, is based on Aristotle's Physics, Book VIII, part 7. In order to understand this argument, we need to consider three kinds of change: (i) substantial change, or a radical change of form (where one thing turns into another); (ii) accidental change (where a thing undergoes qualitative or quantitative change, but retains its identity); and (iii) local change, or a change in position (where a thing moves from one place to another). Aristotle sought to explain the first two kinds of change (substantial and accidental change) in terms of the last (local change). He argued that bodily movement had to be logically prior to all other kinds of change, as neither accidental change nor radical substantial change could possibly take place in the absence of motion. Both accidental and substantial change are thus logically posterior to local change.

Now, in Aristotle's day, the heavenly bodies were believed to be naturally indestructible and unvarying in their physical properties; movement was the only change these bodies were thought to undergo (think of the phrase: "the stars in their courses"). On Earth, by contrast, even the most radical kinds of changes are commonplace: things are transformed into new kinds of things all the time. Moreover, in ancient times, the heavenly bodies were thought to control all natural movements occurring on the Earth, which was believed to occupy an inferior place in the cosmos: the Earth wasn't viewed as the center of the universe, so much as its filthy basement, where all the foul and perishable things congregated. Thus from Aristotle's perspective, it made sense to suppose that the movements of the heavenly celestial bodies caused all local movements occurring on Earth, and that these movements caused all of the various kinds of natural changes (i.e. accidental and substantial changes) occurring on Earth.

However, neither Aristotle nor Aquinas believed that the movements of the heavenly bodies determined everything occurring on Earth. For one thing, the mere fact that the movements of celestial bodies play a causal role in generating new forms does not necessarily imply that the celestial bodies are sufficient to accomplish this task alone, for all kinds of forms. There may be other special conditions that need to be satisfied.

Moreover, Aquinas' argument in his Summa Contra Gentiles Book II chapter 43, paragraph 6 applies only to natural, physical changes. However, Aquinas believed the intellect to be immaterial; hence human choices were not controlled by the movements of the heavenly bodies.

Bearing all this in mind, let us now examine the first part of Aquinas' argument in his Summa Contra Gentiles Book II chapter 43, paragraph 6:

[6] Then, too, motion in respect of form is naturally posterior to local motion, since the former is the act of that which is more imperfect, as Aristotle proves [Physics, VIII, 7]. Now, in the natural order, things posterior are caused by things prior. Therefore, motion with respect to form is caused by local motion. The first local motion, however, is that of the heaven. Hence, all motion toward form is brought about through the mediation of the heavenly motion. Consequently, things that cannot be produced in that way cannot be made by an agent capable of acting only by means of movement; and, as we have just shown, the agent that can act only by inducing form into matter must be that kind of agent.

Here, Aquinas argues that if there are certain kinds of things that cannot be produced by the movement of the heavens, these things will need to be produced by a more specific kind of agent, which "can act only be inducing form into matter."

The stage is now set for Aquinas to argue that certain kinds of animals, namely those that are "generated from seed," cannot be produced by the movements of the heavenly bodies, but only by a very specific formative agent: the seed of the male parent. This brings us to the second part of Aquinas' argument.

(b) Why Aquinas believed that the movements of the heavenly bodies couldn't explain the origin of animals that are naturally "generated from seed"

Let us recapitulate the argument so far. In Aquinas' day, the movements of the heavenly bodies were regarded as playing a vital part in regulating changes on Earth - including animal reproduction. Even in human reproduction, the movements of the stars were believed to play a vital role. Like most of his contemporaries, Aquinas assumed that for some simple kinds of animals, the action of the heavenly bodies on dead or decaying matter was sufficient to generate the forms of new baby animals.

However, in the passage cited above (Summa Contra Gentiles Book II chapter 43, paragraph 6), Aquinas went on to argue that the heavenly bodies were insufficient to generate the forms of new baby animals, for animals that are naturally "generated only from seed," which Aquinas elsewhere describes as "perfect animals." For these kinds of animals, the heavenly bodies merely played an enabling role in reproduction, as necessary but not sufficient causes of new forms. These animals cannot be generated from dead or decaying matter; they need parents to generate them. The movement of the heavenly bodies is insufficient to generate these animals "without their pre-existence in the species."

Readers will be able to see where Aquinas' argument is heading: if the world had a beginning, then where did the forms of the first "perfect animals" come from? Only God could have produced these forms.

This is precisely what Aquinas argues in his Summa Contra Gentiles Book II, chapter 43, paragraph 6. Let us now look at the second half of the passage:

[6] ...There are, however, many sensible forms which cannot be produced by the motion of the heaven except through the intermediate agency of certain determinate principles pre-supposed to their production; certain animals, for example, are generated only from seed. Therefore, the primary establishment of these forms, for producing which the motion of the heaven does not suffice without their pre-existence in the species, must of necessity proceed from the Creator alone.

How much clearer can you get than that?

OBJECTION 1: No Darwinist maintains that higher animals were spontaneously generated from inanimate matter. Higher animals evolved from lower animals. The neo-Darwinian theory of evolution is perfectly compatible with Aquinas' observation that some animals are generated only from seed, if "seed" is understood to include both the male and female gametes. However, the fact that an animal is generated only from "seed" does not mean that it couldn't have evolved from some other kind of animal. Hence, it seems, Aquinas' argument fails to demonstrate that each kind of animal generated from "seed" must have been produced by God, and his attempt to show that the higher animals could not have arisen naturally from inanimate matter is beside the point.

REPLY: The foregoing objection rests on a profound misunderstanding. The reader will recall that according to Aquinas, the seed had to be seed of the right kind - i.e. from a parent of the same kind. This stipulation rules out the possibility of "perfect animals" evolving from other kinds of animals, and since we have already shown that these animals cannot be spontaneously generated from dead or decaying matter, it follows that the first perfect animals must have been produced by God.

Aquinas explained the need for the right kind of "seed" when generating perfect animals, in his Summa Contra Gentiles Book III, chapter 102, paragraph 5 (That God Alone Can Work Miracles):

... [P]erfect animals are not generated by celestial power alone, but require a definite kind of semen; however, for the generation of certain imperfect animals, celestial power by itself is enough, without semen.

Additionally, in his Summa Theologica I, q. 72 a. 1, reply to obj. 3, Aquinas explicitly asserted that perfect animals were generated by a parent of the same kind:

Reply to Objection 3. In other animals, and in plants, mention is made of genus and species, to denote the generation of like from like.

The Darwinist's assertion that higher animals evolved from lower animals overlooks Aquinas' essentialism (see "Smoking Gun" number 8 above), which would have ruled out this option for him. Until Darwinists can demonstrate the falsity of essentialism at all taxonomic levels, and not just at the level of the biological species, Aquinas' objection to evolution remains a valid one. The fact that a wolf can evolve into a dog doesn't imply that a fish can evolve into a man.

Finally, the foregoing neo-Darwinian objection fails to address the question: what about the very first animal to be generated from "seed"? Where did it come from? Aquinas' argument precludes the possibility of it being generated from some other living creature or from non-living matter. That only leaves God as a possible cause.

Whatever a neo-Darwinian evolutionist may think of Aquinas' premises, the logic of his argument is unimpeachable, and it definitively rules out evolution.

OBJECTION 2: Doesn't Aquinas also say that there were no miracles during the six days of Genesis 1, in his Quaestiones Disputatae de Potentia Dei Q. VI article I, objection 9 (Can God do anything in creatures that is beyond Nature, against Nature, or contrary to the course of Nature?), where he writes, "Now in the works of the six days he [God] did nothing contrary to the course of nature"?

REPLY: 1. No, he doesn't say that. The objection itself relates only to miracles of a particular kind: those that run contrary to the course of Nature (e.g. Shadrach surviving unharmed in the fiery furnace - see Daniel 3:26-27). As St. Thomas explains in his Quaestiones Disputatae de Potentia Dei Q. VI article II, miracles that run contrary to the course of Nature are in a different category from miracles that are beyond the power of Nature (e.g. bringing a dead body back to life). In his Reply to the Ninth Objection, in article 1 (Quaestiones Disputatae de Potentia Dei Q. VI article I, Reply to the Ninth Objection), Aquinas acknowledges that "it was not befitting that anything should be done miraculously contrary to the course of nature, when nature itself was being established." However, in producing animals and human beings directly, God wouldn't have had to oppose Nature; instead, He would have been doing something beyond the power of Nature. That's why Aquinas describes God's production of Adam and Eve's bodies, the resurrection of a dead body, and giving sight to a blind person, as "changes that surpass the order of nature," in his Summa Theologica I, q. 91, article 2, reply to objection 3, and not as changes that run contrary to Nature.

2. As we saw in the passages cited above (Summa Theologica I, q. 71 art. 1, Reply to Objection 1 and Summa Contra Gentiles Book II, chapter 43, paragraph 6), Aquinas says very clearly that God did indeed produce animals and human beings by his own immediate power, and that He acted alone when He did so. So unless you want to accuse Aquinas of contradicting himself, you'll have to admit that he claims God acted supernaturally when He produced the first animals.

3. Aquinas has a very strict definition of "miracle," which he explains in his Quaestiones Disputatae de Potentia Dei Q. VI, article II (Can everything that God does without natural causes or contrary to the course of Nature be called a miracle?) (see "I answer that..." and "Reply to the Third Objection"). For Aquinas, a miracle is an observable effect produced by God within the natural world, which either goes beyond the power of Nature (e.g. the raising of a dead body), or runs contrary to Nature (e.g. Shadrach surviving unharmed in the fiery furnace), or is performed independently of natural causes (e.g. turning water into wine - vines do this naturally all the time when they take in water from the soil, but Jesus did it instantaneously at Cana, without recourse to a natural agent). Thus the creation of heaven and earth was not a miracle for Aquinas, as the universe was created ex nihilo. By contrast, miracles take place within an already existing natural world. Miracles are produced in pre-existing matter, not created ex nihilo. The creation of a human soul is not a miracle either, as it's created ex nihilo. What about the works of the six days in Genesis 1? Aquinas writes that "God does not work miracles except in creatures that already exist" (Quaestiones Disputatae de Potentia Dei Q. VI article I, Reply to the Ninth Objection), so God's supernatural production of the first animals would not have been a miracle, technically speaking, even though it clearly went beyond the power of Nature.

Where Professor Tkacz contradicts St. Thomas:

In his article for the journal This Rock, Professor Tkacz wrote:

Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature. The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

Note the dogmatism in Professor Tkacz's language: "there must exist some explanatory cause in nature." Tkacz's position here is completely at variance with that of Aquinas, who held that all animals that are "naturally generated from seed" must have been immediately produced by God alone, in the beginning.

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A giraffe. Aquinas would have called the giraffe a "perfect animal." According to Aquinas, the first giraffe must have been produced immediately by God: too many conditions would need to be satisfied for Nature to produce such a perfect animal.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 10

"SMOKING GUN" Number 10 (This is Aquinas' proto-Intelligent Design Argument):

THE "HIGHER", MORE COMPLEX ANIMALS MUST HAVE BEEN PRODUCED IMMEDIATELY BY GOD, AND GOD ALONE.

Aquinas also put forward a proto-Intelligent Design Argument: the extreme specificity of the conditions required to form "perfect animals," due to their high level of complexity, precludes the possibility of their having originated from non-living matter.

More precisely: God alone could have produced the forms of the various kinds of higher animals (or "perfect animals," as Aquinas calls them), when they first appeared, as they were too complex and required too many conditions to be satisfied for their formation to have occurred by natural processes acting on non-living matter. And as we saw in "Smoking Gun" number 8 above, Aquinas also clearly taught that new species cannot arise through mutation, so they could not have evolved from other living organisms either.

Where Aquinas says this:

Aquinas' argument on this point has to do with what he calls "perfect animals," which he believed were originally produced immediately by God, according to their kind.

What's so special about "perfect animals"?

Following Aristotle, Aquinas believed that there were various grades of perfection amongst animals. I shall quote from "Aristotle: The Growth and Structure of His Thought" by G. E. R. Lloyd, Cambridge University Press, 1968, p. 87:

He [Aristotle] goes on to distinguish animals according to their modes of reproduction and embryonic development. According to this criterion there are five main modes, ranging from the most perfect animals, which are viviparous, through those animals that produce either a perfect or an imperfect egg, down to the insects, which do not produce an egg at all, but only a larva, which becomes, he believes, egg-like as it develops.

Animals belonging to the highest grade were called perfect animals.

In his writings, Aquinas sometimes uses the term "perfect animal" in a broad sense, to denote any animal is naturally "generated from seed" - i.e. an animal that reproduces sexually and breeds true to type (e.g. in his Summa Theologica I, q. 92 art. 1, Summa Contra Gentiles Book III, chapter 102, paragraph 5). But in other passages, Aquinas uses a narrow definition of "perfect animals." In this narrower, more technical sense, the category of "perfect animals" was roughly equivalent to the class of mammals (excepting very small mammals such as rats and mice, which were believed to be spontaneously generated). For Aristotle, and for Aquinas, "perfect animals," in the strict sense of that term, were distinguished by the following criteria:

(i) they require a male's "seed" in order to reproduce. This means that they can only reproduce sexually, and that they always breed true to type - unlike the lower animals, which were then commonly believed to be generated spontaneously from dead matter, and which were incapable of breeding true to type, when reproducing sexually;

(ii) they give birth to live young, instead of laying eggs - in other words, they are viviparous;

(iii) they possess several different senses (unlike the lower animals, which possess only touch);

(iv) they have a greater range of mental capacities, including not only imagination, desire, pleasure and pain (which are found even in the lower animals), but also memory and a variety of passions with a strong cognitive component, including anger;

(v) they are capable of locomotion;

(vi) generally speaking, they live on the land;

(vii) they often hunt lower animals, which are less perfect than themselves; and

(viii) they have complex body parts, owing to their possession of multiple senses and their more active lifestyle ("perfect animals have the greatest diversity of organs" and "they have more distinct limbs").

Animals that satisfy the first criterion are "perfect animals" in the broad sense; animals that satisfy the other criteria are "perfect animals" in the narrow sense of the term. Note: Aquinas, following Aristotle, sometimes referred to the "lower" animals (e.g. sponges, sea stars, oysters) as "imperfect animals." However, for Aquinas, these animals were imperfect in a purely relative sense: they lacked some of the capacities of "higher" animals. As we'll see in "Smoking Gun" number 13 below, Aquinas taught that all of God's creatures were perfectly made, in relation to their proper ends.

Aquinas mentions each of the eight conditions listed above at various places in his writings, notably in his Summa Contra Gentiles Book II chapter 72, paragraph 5, Summa Theologica I, q. 71 art. 1, and Summa Theologica I, q. 72 art. 1, Reply to Objection 1 (The Work of the Sixth Day). Here are the relevant excerpts:

In his De Coelo, Book II Lecture 13, paragraph 411, Aquinas defines an animal's perfection in terms of the variety of its bodily parts (i.e. its anatomical complexity):

For animals of this sort, the more perfect they are, the greater variety do they exhibit in their parts."

In his Summa Contra Gentiles Book II chapter 72, paragraph 5 (That The Soul Is In The Whole Body and Each Of Its Parts), Aquinas explains why perfect animals require a greater variety of parts:

Now, the higher and simpler a form is, the greater is its power; and that is why the soul, which is the highest of the lower forms, though simple in substance, has a multiplicity of powers and many operations. The soul, then, needs various organs in order to perform its operations, and of these organs the soul's various powers are said to be the proper acts; sight of the eye, hearing of the ears, etc. For this reason perfect animals have the greatest diversity of organs; plants, the least.

In his Summa Theologica I, question 71 (The Work of the Fifth Day), Aquinas explains why land animals require a more highly developed anatomy and mode of reproduction than birds and fishes:

[L]and animals are more perfect than birds and fishes which appears from the fact that they have more distinct limbs, and generation of a higher order. For they bring forth living beings, whereas birds and fishes bring forth eggs.

Aquinas says the same thing in his Summa Theologica I, q. 72 art. 1, Reply to Objection 1 (The Work of the Sixth Day):

Reply to Objection 1. The different grades of life which are found in different living creatures can be discovered from the various ways in which Scripture speaks of them, as Basil says (Hom. viii in Hexaem.). The life of plants, for instance, is very imperfect and difficult to discern.... But amongst animals, those that live on land are, generally speaking, more perfect than birds and fishes, not because the fish is devoid of memory, as Basil upholds (Hom. viii in Hexaem.) and Augustine rejects (Gen. ad lit. iii), but because their limbs are more distinct and their generation of a higher order, (yet some imperfect animals, such as bees and ants, are more intelligent in certain ways).

Unlike many of the "lower" animals, perfect animals are highly mobile. In his De Coelo, Book II Lecture 2, paragraph 301 Aquinas writes that perfect animals "which not only sense but move with local motion, possess all these parts, namely, right and left, before and behind, above and below."

Aquinas explains why it is fitting that perfect animals should be nourished by less perfect animals in his Summa Contra Gentiles Book III, chapter 22, paragraph 8:

[8] And since a thing is generated and preserved in being by the same reality, there is also an order in the preservation of things, which parallels the foregoing order of generation. Thus we see that mixed bodies are sustained by the appropriate qualities of the elements; Plants, in turn, are nourished by mixed bodies; animals get their nourishment from plants: so, those that are more perfect and more powerful from those that are more imperfect and weaker. In fact, man uses all kinds of things for his own advantage: some for food, others for clothing. That is why man was created nude by nature, since he is able to make clothes for, himself from other things; just as nature also provided him with no appropriate nourishment, except milk, because he can obtain food for himself from a variety of things. Other things man uses for transportation, since we find man the inferior of many animals in quickness of movement, and in the strength to do work; other animals being provided, as it were, for his assistance. And, in addition to this, man uses all sense objects for the perfection of intellectual knowledge. Hence it is said of man in the Psalms (8:8) in a statement directed to God: "Thou hast subjected all things under his feet," And Aristotle says, in the Politics I [5: 1254b 9], that man has natural dominion over all animals.

Finally, in his Commentary on Aristotle's De Sensu et Sensato, Prologue, Commentary on 436a8, Aquinas argues that perfect animals have a greater range of mental capacities than other animals:

For imperfect animals have, of the senses, only touch; they also have imagination, desire, and pleasure and pain, although these are indeterminate in them... But memory and anger are not found in them at all, but only in perfect animals.

Aquinas' Intelligent Design-style argument

As we saw in "Smoking Gun" number 9, Aquinas argued that the first perfect animals could only have been produced by God, and not by the power of Nature. Two centuries prior to Aquinas, the Persian philosopher Avicenna (c. 980-1037) had upheld a contrary view, arguing that all animals were capable of being generated naturally from the elements; hence no supernatural act of God was required in order to account for their origin. In his writings, Aquinas puts forward two refutations of Avicenna.

First, he asserted that animals that were naturally "generated from seed" could not have arisen in this way. These animals, he maintained, must originally have been produced by God. We examined this argument of Aquinas in "Smoking Gun" number 8.

However, Aquinas also put forward a second argument against Avicenna. This argument is an Intelligent Design-style argument, based on the complexity of perfect animals. Because their bodies are more perfect, more conditions are required to produce them. According to Aquinas, the heavenly bodies (which were then believed to initiate all changes taking place on Earth) were capable of generating simple animals from properly disposed matter, but they were incapable of producing perfect animals, because too many conditions would need to be specified to produce such creatures by natural means. As Aquinas writes in his Summa Theologica I, q. 91 art. 2, Reply to Objection 2 (Whether The Human Body Was Immediately Produced By God?):

Reply to Objection 2. Perfect animals, produced from seed, cannot be made by the sole power of a heavenly body, as Avicenna imagined; although the power of a heavenly body may assist by co-operation in the work of natural generation, as the Philosopher says (Phys. ii, 26), "man and the sun beget man from matter." For this reason, a place of moderate temperature is required for the production of man and other animals. But the power of heavenly bodies suffices for the production of some imperfect animals from properly disposed matter: for it is clear that more conditions are required to produce a perfect than an imperfect thing.

Why are more conditions required to produce perfect animals? As we have seen, Aquinas held that these animals have more complex body parts, partly due to their possession of several senses, but also because of the demands of their active lifestyle (they live on the land and often hunt other creatures). In other words, what Aquinas is doing here is sketching an Intelligent Design argument: the complexity of perfect animals' body parts and the high degree of specificity required to produce them preclude them from having a non-biological origin. According to Aquinas, the only way they can be naturally generated is from "seed." From this it follows that the first perfect animals must have been produced by God alone.

Aquinas clearly articulates this conclusion in a passage we examined above, when we looked at his "Smoking Gun" number 9. The relevant passage is contained in Aquinas' Summa Contra Gentiles Book II chapter 43, paragraph 6 (That The Distinction of Things Is Not Caused By Some Secondary Agent Introducing Diverse Forms Into Matter), where he argues that the action of the heavenly bodies - which were believed to cause changes occurring on Earth - would not have been sufficient to produce the forms of the first animals that are naturally "generated only from seed":

[6] ... There are, however, many sensible forms which cannot be produced by the motion of the heaven except through the intermediate agency of certain determinate principles pre-supposed to their production; certain animals, for example, are generated only from seed. Therefore, the primary establishment of these forms, for producing which the motion of the heaven does not suffice without their pre-existence in the species, must of necessity proceed from the Creator alone.

Of course, a modern evolutionist would respond to Aquinas' Intelligent Design-style argument by saying that of course, non-living matter cannot suddenly transmute into the body of a mammal - that would indeed be a miracle. But over billions of years, it could have produced the first life, which by a series of almost imperceptible step-by-step transitions, could have given rise to living things in all their diversity - including mammals.

However, we have already seen (in "Smoking Gun" number 8) that Aquinas ruled out the possibility of evolution, as he held that new species can only arise through hybridization (which presupposes the existence of two kinds of advanced creatures to produce), grafting (which presupposes the existence of different kinds of plants) and spontaneous generation (which can only produce simple life-forms, according to Aquinas). Aquinas also clearly taught that new species cannot arise through mutation.

Another problem with the evolutionist's response is that it simply assumes (a) that Darwinian evolution is an adequate mechanism to generate new families, orders, classes and phyla of organisms, and (b) that all of the complex structures found in animals could have arisen by natural processes. Neither of these assumptions has been demonstrated. All we can be sure of is that one biological species can evolve into another one, over time. Additionally, there are converging lines of circumstantial evidence for common descent, which implies that there is continuity between all kinds of living things, at the material level. However, there is no experimental evidence of evolution occurring at the level of the family or above, by natural processes; or of irreducibly complex structures (i.e. forms) originating by natural processes. And as we saw in Smoking Gun number 7, Aquinas would not have been impressed by any other kind of evidence, as he held that the processes that give rise to various kinds of things are regular, repeatable processes. Hence he would surely have demanded a reproducible experiment, to support the fantastic assertion that a bacterium can, over the course of time, evolve into a human being.

Where Professor Tkacz contradicts St. Thomas:

Here's what Professor Tkacz says in the revised version of his talk to the Gonzaga Socratic Club.

Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature. The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

This is totally at odds with Aquinas' argument above, that the forms of complex animals must have been immediately produced by God.

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Michelangelo, "The Creation of Adam," c. 1511. Fresco from the Sistine Chapel.
According to Aquinas, the first human beings must have been produced immediately by God.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 11

"SMOKING GUN" Number 11:

THE BODIES OF THE FIRST HUMAN BEINGS MUST HAVE BEEN PRODUCED IMMEDIATELY BY GOD, AND GOD ALONE.

According to Aquinas, the bodies of Adam and Eve must have been produced immediately by God alone.

The bodies of the first human beings must have been produced immediately by God, as there was no other way in which they could have been produced. Other immaterial intelligences (e.g. angels) could not have produced Adam and Eve, as angels have no power to command matter, and are incapable of producing new forms in embodied beings (such as human beings). Nor could natural forces have done the job, for according to Aquinas, there's only one natural way to produce a new human body, and that's from human parents (see "Smoking Gun" number 8 above, on essentialism), which Adam and Eve obviously lacked. Hence if the human race had a beginning, then we can be sure that the immediate action of God was responsible, and not some natural process, such as Darwinian evolution.

Where Aquinas says this:

Aquinas needs to demonstrate two points regarding the formation of the first human beings, in order to show that God must have been responsible: first, other immaterial intelligences (e.g. angels) could not have produced the first human beings; second, natural agents could not have done so either. Aquinas uses the production of Adam to argue the first point, and the production of Eve to argue the second.

(a) The Production of Adam

In his Summa Theologica I, q. 91, article 2 (Whether the human body was immediately produced by God), Aquinas expressly teaches that only God was capable of producing the forms of the first human beings, Adam and Eve. According to Aquinas, not even intelligent spiritual beings, such as the angels, were capable of producing the first human body - even when working with pre-existing matter. Only God could have done this. As Aquinas explained in his Summa Theologica I, q. 65 art. 4, "the corporeal forms that bodies had when first produced came immediately from God, whose bidding alone matter obeys, as its own proper cause." Thus according to Aquinas, angels have no power to command matter to assume complex forms; only God, the Creator of matter, can do that. St. Augustine says the same thing in De Trinitate iii, 8: "We must not suppose that this corporeal matter serves the angels at their nod, but rather that it obeys God thus." Here is what Aquinas writes on the formation of Adam's body:

I answer that, The first formation of the human body could not be by the instrumentality of any created power, but was immediately from God. Some, indeed, supposed that the forms which are in corporeal matter are derived from some immaterial forms [i.e. immaterial intelligences - VJT]; but the Philosopher refutes this opinion (Metaph. vii), for the reason that forms cannot be made in themselves, but only in the composite, as we have explained (65, 4); and because the agent must be like its effect, it is not fitting that a pure form, not existing in matter, should produce a form which is in matter, and which form is only made by the fact that the composite is made. So a form which is in matter can only be the cause of another form that is in matter, according as composite is made by composite. Now God, though He is absolutely immaterial, can alone by His own power produce matter by creation: wherefore He alone can produce a form in matter, without the aid of any preceding material form. For this reason the angels cannot transform a body except by making use of something in the nature of a seed, as Augustine says (De Trin. iii, 19). Therefore as no pre-existing body has been formed whereby another body of the same species could be generated, the first human body was of necessity made immediately by God.

Note: St. Augustine of Hippo (354-430) had supposed that at the beginning of creation, God had scattered invisible germinal "seeds" of all the different kinds of plants and animals around the world, and that these later developed into mature adults, each according to their kind. (I'll say more about Augustine's bizarre theory in a future post.) But as Aquinas points out, even if this were the case, God still did the original work of making the "seeds" - and angels were powerless to produce any creatures without them.

In the same passage, Aquinas responds to an objection to the idea that supernatural agency was responsible for the formation of Adam's body: since the production of the first human body was a material change, it should have a naturalistic explanation. In St. Thomas' day, all changes occurring on earth were supposed to be explicable in terms of the movements of heavenly bodies, so (the objection went) we should be able to explain the appearance of the first human body in the same way. Aquinas responds that some material changes are beyond the power of Nature to produce. In this passage, Aquinas even likens the production of Adam's body from slime to the miracle of raising the dead to life, showing that he regarded it as clearly beyond the power of Nature:

Objection 3. Further, nothing is made of corporeal matter except by some material change. But all corporeal change is caused by a movement of a heavenly body, which is the first movement. Therefore, since the human body was produced from corporeal matter, it seems that a heavenly body had part in its production.

Reply to Objection 3. The movement of the heavens causes natural changes; but not changes that surpass the order of nature, and are caused by the Divine Power alone, as for the dead to be raised to life, or the blind to see: like to which also is the making of man from the slime of the earth.

(b) The Production of Eve

In his Summa Theologica I, q. 92, article 2, Reply to Objection 2 (Whether woman should have been made for man?), Aquinas argues that whereas Nature can only produce its effects from the right kind of matter, God, Who is infinite, can produce whatever organisms He wishes from any kind of matter. Thus He is perfectly capable of making a man (Adam) from the slime of the earth, and a woman (Eve) from a man's rib, if He so wishes:

Objection 2. Further, things of the same species are of the same matter. But male and female are of the same species. Therefore, as man was made of the slime of the earth, so woman should have been made of the same, and not from man.

Reply to Objection 2. Matter is that from which something is made. Now created nature has a determinate principle; and since it is determined to one thing, it has also a determinate mode of proceeding. Wherefore from determinate matter it produces something in a determinate species. On the other hand, the Divine Power, being infinite, can produce things of the same species out of any matter, such as a man from the slime of the earth, and a woman from out of man.

Later on, in his Summa Theologica I, q. 92, article 4 (Whether the woman was formed immediately by God?), Aquinas elaborates his argument that only God could have produced the body of Eve. The crux of his argument is that a perfect animal (which was defined in "Smoking Guns" number 9 and number 10 above) can only be naturally generated from the "seed" of a parent animal of the same species. Hence the natural generation of a human being requires human parents. The first humans obviously had none; hence they could not have been generated naturally. Aquinas argues that only God, the Author of Nature, could produce an effect outside the order of Nature; hence only God could have made the body of Eve:

On the contrary, Augustine says, in the same work [De Trinitate iii, 4 - VJT]: "God alone, to Whom all nature owes its existence, could form or build up the woman from the man's rib."

I answer that, As was said above (2, ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man....

Where Professor Tkacz contradicts St. Thomas:

Here's what he says in the revised version of his talk to the Gonzaga Socratic Club.

The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

Presumably that includes human beings. Thus Professor Tkacz believes that the bodies of the first humans must have originated as a result of natural processes; whereas Aquinas held that natural forces could not have produced the first man and woman. Clearly, Professor Tkacz' thinking and that of Aquinas are poles apart.

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A section of DNA. According to ID advocate Dr. Don Johnson, DNA stores data which is used by a suite of programs running within each cell in the body of an organism. These programs must therefore contain instructions or messages on how to use this data, which are written in some kind of programming language. However, Aquinas held that language is an effect peculiar to intelligent beings. Hence if he were alive today, he would insist that an Intelligent Being must have coded the programs running within the cells of living organisms.
Professor Tkacz, on the other hand, maintains that even the most complex features of organisms must have a natural explanation.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 12

"SMOKING GUN" Number 12:

LANGUAGE, NO MATTER WHERE IT IS FOUND, IS A HALLMARK OF INTELLIGENCE.

According to Aquinas, language is an effect peculiar to rational beings, and therefore is incapable of having a physical explanation. Language must be produced by an intelligent being.

Aquinas wrote that any observable effects which are peculiar to intelligent beings could not possibly be caused by the natural action of bodies, and therefore could not possibly have a physical explanation.

Aquinas also taught that language is an effect peculiar to intelligent beings..

My conclusion: since we now know that there is a suite of programs running within the cells of each living organism, and that these programs are quite literally written in some kind of programming language which our best scientists are still struggling to fully understand, then St. Thomas Aquinas, if he were alive today, would unhesitatingly declare that an intelligent agent produced these programs, and not some physical process. (I will say more about these cellular programs in Part Five of my reply to Professor Tkacz.)

Where Aquinas says this:

In his Summa Contra Gentiles Book III, chapter 104 (see paragraphs 2 and 3) (That the Works of Magicians Are Not Solely Due To The Influence Of Celestial Bodies), Aquinas argues that at least some of the special effects wrought by magicians must be caused not by the stars (as some people held), but by intelligent agents (i.e. demons). Aquinas insisted that demons were responsible, because some of these magical effects (e.g. voices coming from the statues of idols - see paragraphs 10 and 11) involved speech - i.e. intelligible discourse about various subjects - which is an act peculiar to rational beings. In paragraph 3 below, Aquinas argues that language is peculiar to rational beings:

[1] There have been some who say that works of this kind, which are astonishing to us when accomplished by the arts of magic, are not performed by spiritual substances but by the power of celestial bodies. And indication of this is seen in the fact that the precise position of the stars is carefully noted by those who perform these works. Moreover, they make use of certain herbs, and other corporeal things, as aids in the preparation, as it were, of low-grade matter for the reception of the influence of celestial power.

[2] But this view is clearly opposed by the apparitions. Indeed, since it is not possible for understanding to be caused by corporeal principles, as we proved above, it is impossible for effects peculiar to intellectual nature to be caused by the power of a celestial body. Now, among these workings of the magicians some events appear which are the proper functions of a rational nature. For instance, answers are given concerning things removed by theft, and concerning other such matters, and this could be done only through understanding. So, it is not true that all effects of this kind are caused solely by the power of celestial bodies.

[3] Again, speech is itself an act peculiar to a rational nature. Now, certain agents that speak to men appear in these performances, and they reason discursively about various matters. Therefore, it is not possible for things like this to be done solely by the power of celestial bodies.

My conclusion: if it could be shown that there is an actual set of programs running within each cell in the body of a living organism (as Intelligent Design proponent Dr. Don Johnson claims), with coded instructions (i.e. language) for maintaining each cell's biological processes, then St. Thomas would immediately have deduced that no natural physical process could possibly have created it. First, language is an effect peculiar to intelligent beings, as no other kind of agent is capable of producing language. Second, Aquinas believed that he could demonstrate philosophically that the operations of the intellect are non-bodily operations. Hence the presence of programs running within each cell of an organism would constitute deductive proof of intelligent agency for Aquinas. This is a "strong," deductive Intelligent Design argument.

On the other hand, the "standard" Intelligent Design argument, that the best explanation for the digital code we see in DNA is an intelligent agent, is not an argument that Aquinas would have likely employed in its current form, for three reasons:

(i) digital code as such is not an effect which is inherently peculiar to rational beings, unlike language. On the other hand, the genetic instructions for making an organism, which are written in this digital code, certainly qualify as language;

(ii) the "standard" ID argument employs abductive logic, or inference to the best explanation, but as far as I can tell, Aquinas was not familiar with abductive logic (a term which was not coined until the nineteenth century), although he was of course perfectly familiar with Aristotle's inductive and deductive logic;

(iii) the "standard" ID argument employs probability calculations, but in the thirteenth century, the mathematical notation for representing probabilities had not yet been invented. That's why Aquinas confines himself to writing about things that happen always, for the most part, or rarely, when discussing the frequency of events.

A program, on the other hand, is necessarily written in some sort of language, so a program in the cell's genome would constitute deductive proof of intelligent agency for Aquinas, as no other kind of agent is capable of producing language. I conclude that St. Thomas would certainly have endorsed "strong," deductive Intelligent Design arguments, but that he would likely not have made use of "standard," abductive ID arguments, when arguing with skeptics.

Objection 1:

Even a deductive-style Intelligent Design argument would be inadequate to establish the existence of a transcendent Creator (i.e. God). Other intelligent beings (e.g. aliens) could have created the first life on Earth.

Reply:

(1) Writing in the thirteenth century, Aquinas had no means of scientifically estimating the age of the cosmos, or even of demonstrating that it had a beginning. However, scientists now know that the age of the cosmos is finite, which makes it legitimate to ask where the first generation of aliens came from. Who made them?

(2) A recent paper in arXiv.org by the esteemed physicists Steve Hsu and Tony Zee, entitled Message in the Sky suggests that fluctuations in cosmic microwave background radiation found throughout the universe could contain a communique from our universe's Creator, according to an interesting article in Seed magazine by Adnaan Wasey, dated November 8, 2005. The two physicists have also described methods to decode the statement, which requires "no direct intervention in the subsequent evolution of the universe."

By creating a map of temperature differences in the cosmic radiation, it would be possible to obtain a message in a string of bits, zeros and ones. As many as 100,000 of these binary bits could be read, but Hsu said it would require another generation of satellites and another 15 years to achieve the resolution to perceive it. However, it would be a message that could be read by all inhabitants of the universe, he claimed.

If, for instance, God were to encode a message specifying the Grand United gauge group, which describes the physics of our cosmos, that would be enough for us to identify the message as the work of an Intelligence that created - and hence transcended - the cosmos. Aquinas regarded language as a hallmark of intelligence; hence, a cosmic message must be the work of a Cosmic Intelligence.

In a reply to Hsu and Zee's paper, physicists Douglas Scott and J.P. Zibin argue that the content of any message in the sky would depend on the observer's location in space and time, but concede that the cosmic microwave radiation could still hold a vast amount of information. While the authors do not espouse Hsu and Zee's theistic proposal, they acknowledge at the end of their article that "there is indeed a 'message in the sky' - it is the fact that the CMB anisotropies allow us to determine very precisely the large-scale structure of the observable Universe, and to probe physics at the highest energies."

In my opinion, the possibility that the cosmic microwave radiation embodies some sort of mathematical code specifying the structure of the cosmos is worthy of further exploration. If such a code contained a sequence-specific message - perhaps one that helped generate the structure of the cosmos in the first place, a bit like the way DNA does in living things - then it would constitute language, and hence qualify as a hallmark of intelligence for Aquinas.

Objection 2:

Even if the Maker of the Cosmos is outside our cosmos, it need not be God. It could be some finite, intelligent being living in a universe larger than our own. In a recent news report, the astronomer John Gribbin has argued that the universe was designed by intelligent beings with minds similar to our own, and at most only slightly superior to ours. According to Gribbin, these designers fine-tuned the natural constants of our universe, but would have been prevented by the laws of physics from interfering with Nature, after producing our cosmos. Thus Intelligent Design cannot get us to an Infinite God.

Reply:

(1) If it can be shown that the production of life and the subsequent development of irreducibly complex structures in organisms could not have been pre-programmed into Nature, then the emergence of life in our cosmos points to an Intelligence that is not bound by the laws of physics - and is therefore free to act upon the natural world as often as He wishes. I will endeavor to explain why the development of life could not have been pre-programmed into Nature, even by God, in Part Four of my reply to Professor Tkacz (see "Fatal Flaw number 4").

(2) Intelligent Design might even be able to take us to an infinite God, by pointing to some biological trait that no finite intelligence could possibly produce. If, for instance, it turned out that the human brain has an infinite storage capacity, that would point to an Infinite Designer, and not a finite one. (Why do I suspect it might? If you take the Judeo-Christian doctrine of the resurrection of the body seriously, then you have to accept that we'll have brains in Heaven. Heaven lasts forever, and presumably God wants us to remember what we do there. A brain with a finite storage capacity would eventually run out of memory space.)

(3) The beings posited by Dr. John Gribbin would still be contingent; hence it would be legitimate to ask what explained their existence. An infinite regress of per se causes is impossible: you can have an infinite regress of conditions, but you can't have an infinite regress of explanations. So we get back to an Uncaused Cause. This Cause cannot be finite, or it would be contingent, too.

Where Professor Tkacz contradicts St. Thomas:

In his article for the journal This Rock, Professor Tkacz wrote:

Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature. The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

Presumably, by "natural explanation" Professor Tkacz means: some kind of physical explanation. If this is correct, then even if Professor Tkacz were shown some observable effects within organisms' cells which are peculiar to intelligent beings (e.g. a program in their genome, or a highly specified digital code), he would still be committed to saying, on a priori grounds, that there must be a physical explanation.

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The human eye. According to evolutionists, the vertebrate eye is inherently flawed in its design. Aquinas, however, insisted that "God's works are perfect" (Deuteronomy 32:4) and that "God made man right" (Ecclesiastes 7:30).

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SHORT Version of "Smoking Gun" Number 13

"SMOKING GUN" Number 13:

ALL OF GOD'S WORKS ARE PERFECTLY DESIGNED IN RELATION TO THEIR ENDS. HENCE THERE ARE NO BAD DESIGNS IN NATURE.

According to Aquinas, every kind of living thing God that produced in the natural world is perfectly designed for the biological ends that God intends it to realize.

All of God's works are perfect, where the word "perfect" is defined in relation to each creature's proper ends. "Perfect" does not mean "optimal," but it does mean "free from flaws in its design." For instance, the vertebrate eye, whose proper end is seeing, is perfect for that job, because God made it with unsurpassable wisdom and goodness. Hence according to Aquinas, there are no bad designs in nature.

Where Aquinas says this:

In his Summa Theologica I, q. 91, a. 1, Aquinas addresses the question: Whether the Body of the First Man Was Made of the Slime of the Earth? His response begins as follows:

I answer that, As God is perfect in His works, He bestowed perfection on all of them according to their capacity: "God's works are perfect" (Deut. 32:4).

In his Summa Theologica I, q. 91, art. 3, St. Thomas asks whether the body of (the first) man was given an apt disposition. After listing three objections to the design of the human body (which he would later refute), Aquinas responds as follows:

On the contrary, It is written (Ecclesiastes 7:30): "God made man right."

I answer that, All natural things were produced by the Divine art, and so may be called God's works of art. Now every artist intends to give to his work the best disposition; not absolutely the best, but the best as regards the proposed end; and even if this entails some defect, the artist cares not: thus, for instance, when man makes himself a saw for the purpose of cutting, he makes it of iron, which is suitable for the object in view; and he does not prefer to make it of glass, though this be a more beautiful material, because this very beauty would be an obstacle to the end he has in view. Therefore God gave to each natural being the best disposition; not absolutely so, but in the view of its proper end.

Aquinas cites the Biblical verse, "God's works are perfect" (Deuteronomy 32:4) fifteen times in his Summa Theologica, and the Biblical verse, "God made man right" (Ecclesiastes 7:30) no less than four times.

In his Summa Theologica I, q. 25, article 6, reply to objection 1, Aquinas asks whether God can do better than what he does. He answers that God can always make a thing better "as regards the accidents" (i.e. by giving it more desirable add-on features, and thereby improving it as a thing), "although not as regards the substance." For instance, God cannot make a hippopotamus any more of a hippopotamus than it already is. A hippo is a hippo, simply by virtue of being a creature of that kind. If, however, the word "better" is taken to mean "made in a better way" then Aquinas insists that God cannot make a thing any better than He makes it, because He cannot make it with greater wisdom or goodness:

Reply to Objection 1. When it is said that God can make a thing better than He makes it, if "better" is taken substantively, this proposition is true. For He can always make something else better than each individual thing: and He can make the same thing in one way better than it is, and in another way not; as was explained above. If, however, "better" is taken as an adverb, implying the manner of the making; thus God cannot make anything better than He makes it, because He cannot make it from greater wisdom and goodness. But if it implies the manner of the thing done, He can make something better; because He can give to things made by Him a better manner of existence as regards the accidents, although not as regards the substance.

Finally, in his Quaestiones Disputatae de Potentia Dei (Disputed Questions Concerning the Power of God), Q. IV article II, reply to objection 22, Aquinas addresses the question: was matter formed all at once or by degrees? Most Christian theologians taught that the world was made in six days, while St. Augustine of Hippo preferred the view that everything was created perfect, in a single instant, rather than over six days. St. Thomas considered both views compatible with the Catholic faith, but during his lengthy reply, he also touches on the perfection of God's original creation:

[Objection] 22. Augustine (Gen. ad lit. vii, 24, 25) queries whether Adam's soul were made apart from his body at the same time as the angels or at the same time as his body. But there would be no purpose in discussing this question if all things were made at the same time, because then the human body was made at the same time as the angels. It would seem then that in Augustine's opinion all things were not made at the same time.

Reply to the Twenty-second Objection. Augustine (Super Gen. v, 12, 14) holds that at the very beginning of creation certain things specifically distinct were produced in their respective, natures, such as the four elements produced from nothing, as well as the heavenly bodies and spiritual substances: for this kind of production requires no matter either out of which or in which a thing is made. Also that other things are stated to have been created in their seed-forms, for example animals, plants and men, and that these were all subsequently produced in their respective natures in that work by which God after the six days attends to nature previously established, of which work it is said (Jo. v, 17): My Father worketh until now. Moreover he holds that in the production and distinction of things we should see an order not of time but of nature: inasmuch as all the works of the six days were wrought in the one instant of time either actually, or potentially in their seed-forms, in that afterwards they could be made from pre-existent matter either by the Word, or by the active forces with which the creature was endowed in its creation. Wherefore in regard to the first man's soul which, he suggests without asserting it, was created actually at the same time as the angels, he does not hold that it was created before the sixth day, although he holds that on the sixth day it was actually made, and the first man's body as to its seed-forms: for God endowed the earth with a passive potentiality so that by the active power of the Creator man's body could be formed therefrom. Accordingly the soul was actually made at the same time as the body was made in its passive potentiality to God's active power. - Or again, seeing that in truth according to Aristotle (De Anima ii), the soul is not a complete species in itself but is united to the body as the latter's form, and is naturally a part of human nature, we must infer that the first man's soul was not brought into actual existence before the formation of the body, but was created and infused into the body at the same time as the body was formed, even as Augustine holds (Super Gen. x, 17) with regard to other souls. For God produced the first things in their perfect natural state, according as the species of each one required. Now the rational soul being a part of human nature has not its natural perfection except as united to the body. Hence it naturally has its being in the body, and existence outside the body is non-natural to it: so that it was unfitting for the soul to be created without the body.

If then we adopt the opinion of Augustine on the works of the six days, it may be said that as in those six days the body of the first man was not actually formed and produced, but only potentially in its seed-forms: even so his soul was not produced then actually and in itself, but in its generic likeness; and thus preceded the body during those six days not actually and in itself, but in respect of a certain generic likeness, inasmuch as it has an intellectual nature in common with the angels. Afterwards however, in the work whereby God attends to the creature already produced, the soul was actually created at the same time as the body was formed.

Thus Aquinas explicitly teaches that each and every species of creature was produced perfectly by God, in its original state.

The clear implication of the foregoing citations is that there are no bad designs in Nature: everything is made with perfect wisdom and goodness. Hence if we discover apparent imperfections in Nature - e.g. pseudogenes, the laryngeal nerve of the giraffe, or the vertebrate eye - we should take these as a reflection of our ignorance, rather than God's ineptitude. Try telling a Darwinist that!

Where Professor Tkacz contradicts St. Thomas:

Here's what he says in the revised version of his talk to the Gonzaga Socratic Club.

The insights of Aquinas also provide an answer to the recent challenge to Darwinian evolution from ID theory.

I can only conclude that Professor Tkacz personally favors Darwinian evolution, despite his professed neutrality in the previous paragraph, where he appears to hedge his bets: "Observed species of plants and animals may or may not be descendent from common primordial ancestors." In the revised version, Professor Tkacz also insists:

Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature. The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

That sounds pretty Darwinian to me. Now here's the thing: if you accept the scientific premises of neo-Darwinism, you simply can't believe that the design of living things is perfect. Neo-Darwinism tells us that the design of living things is rife with imperfections. The flaws and imperfections in the design of living things were crucial to Darwin's case against creationism, in "The Origin of Species." In a recent PNAS article (May 5, 2010, doi: 10.1073/pnas.0914609107) entitled Footprints of nonsentient design inside the human genome, Professor John Avise spells out the atheistic implications of Darwin's theory:

[M]any complex biological traits are gratuitously complicated, function poorly, and debilitate their bearers. Furthermore, such dysfunctional traits abound not only in the phenotypes but inside the genomes of eukaryotic species. Here, I highlight several outlandish features of the human genome that defy notions of ID by a caring cognitive agent. These range from de novo mutational glitches that collectively kill or maim countless individuals (including embryos and fetuses) to pervasive architectural flaws (including pseudogenes, parasitic mobile elements, and needlessly baroque regulatory pathways) that are endogenous in every human genome.

That's what you have to believe, if you espouse neo-Darwinism. But no Thomist could believe that.

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Left: The kiwi - a flightless bird with wing stumps, found in New Zealand. According to evolutionists, its wing stumps are vestigial and serve no function whatsoever.
Right: A pack of ostriches, Chay Bar Yotvata, Israel. According to evolutionists, ostrich wings serve various limited functions, which are incommensurate with their complexity. Hence they are vestigial.
However, Aquinas repeatedly insisted that "God and Nature make nothing in vain." What's more, he even taught that all of God's works must continue to serve a purpose, so long as they remain in existence.

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SHORT Version of "Smoking Gun" Number 14

"SMOKING GUN" Number 14:

EVERYTHING THAT GOD MADE HAS A PURPOSE; AND EVERYTHING IN NATURE HAS A PURPOSE. HENCE ORGANISMS CONTAIN NO REDUNDANT OR VESTIGIAL FEATURES.

God creates nothing in vain: "nothing is void in God's works." Moreover, "nature does nothing in vain." Hence if we look at the anatomical features that characterize the various kinds of organisms, we will find no redundant features; every feature designed by God has its purpose.

Where Aquinas says this:

In his Summa Theologica III, q. 9, art 4, Aquinas asks whether Jesus Christ had any acquired knowledge as a human being, and argues that of course He did. In the course of his argument, Aquinas writes:

But if in other things God and nature make nothing in vain, as the Philosopher says (De Coel. i, 31; ii, 59), still less in the soul of Christ is there anything in vain.

"God makes nothing in vain" (Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 8, paragraph 91).

"None of God's works have been made in vain" (Summa Theologica I, q. 67, article 4, reply to objection 2 ).

"Nothing is void in God's works" (Summa Theologica I, q. 98, article 2).

"God and nature make nothing in vain" (Summa Theologica III, q. 9, art 4).

"God and nature do nothing in vain" (Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 12, paragraph 113).

"Nature makes nothing in vain" (Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 8, paragraph 91).

"Nature does nothing in vain" (Summa Contra Gentiles Book III, chapter 48, paragraph 11, Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 13, paragraph 132).

"Nothing in nature is in vain" ( Commentary on Aristotle's De Coelo et Mundo, Lecture 8, paragraph 91).

"Nothing is in vain in Nature" (Commentary on Aristotle's De Coelo et Mundo, Book II, Lecture 4, paragraph 336).

What does Aquinas mean by "in vain"?

According to Aquinas, a thing is "in vain" if it is (1) superfluous (serving no purpose), OR (2) unable to realize its purpose, OR (3) directed at an unachievable goal, OR (4) not the goal of anything else.

Here are examples of these different usages of "in vain" in Aquinas:

(1) Superfluous; serving no present purpose

This is the meaning I'll be focusing on, in my discussion of allegedly "vestigial" organs, in Part Two of my reply to Professor Tkacz.

Aquinas certainly taught that everything in Nature serves a purpose, but he went much further than that. Aquinas invoked the axiom that "God does nothing in vain," not only to show that everything in Nature serves a purpose, but that there cannot be anything in Nature that once served a purpose, but no longer does so, and moreover, there will never be a time in the future when something in Nature no longer serves a purpose. Additionally, for Aquinas, a thing is "in vain," not only if it serves no purpose in fact, but if there is a theoretical possibility that it might have served no purpose. Thus Aquinas also insisted that there was not even a theoretical possibility of a situation arising where something in Nature served no purpose.

The following passages illustrate the lengths to which Aquinas went in asserting his claim that God and Nature make nothing in vain:

(a) In his Summa Theologica I, q. 98, article 2 (Whether in the state of innocence there would have been generation by coition), Aquinas addresses the question of whether procreation would have taken place as a result of sexual intercourse, in Paradise. Now, a few of the early Church Fathers, who were rather prudish, had objected to the notion of Adam and Eve copulating in Paradise, and had suggested that if Adam and Eve had not sinned, they would still have had babies, but not as a result of sexual intercourse. These Church Fathers regarded sexual intercourse as inseparably bound up with lustful desires, and hence as incompatible with the original state of innocence before the Fall.

In his article on whether in the state of innocence there would have been generation by coition, Aquinas listed four arguments against the view that sexual intercourse would have taken place in Paradise. After that, Aquinas puts forward a very powerful argument advocating the contrary position, which he strongly endorsed in his own response. The argument went along these lines: if there had been no sexual intercourse in Paradise, then Adam and Eve's genital organs would have been made in vain. But Scripture clearly teaches that God made Adam and Eve, with all their genital organs, in a state of innocence. Hence, there would certainly have been intercourse in Paradise, even if Adam and Eve had not sinned. This argument, which reflects Aquinas' own views, is based on the theological axiom that "nothing is void in God's works." It is not enough that genital organs have a purpose, now; they had to have had a purpose, even if Adam and Eve had not sinned. Here is the argument, as put forward by Aquinas:

On the contrary, God made man and woman before sin (Genesis 1-2). But nothing is void in God's works. Therefore, even if man had not sinned, there would have been such intercourse, to which the distinction of sex is ordained. Moreover, we are told that woman was made to be a help to man (Genesis 2:18-20). But she is not fitted to help man except in generation, because another man would have proved a more effective help in anything else. Therefore there would have been such generation also in the state of innocence.

Aquinas realized that this was not an absolutely conclusive reply, as the more prudish Church Fathers could still have argued that God gave Adam and Eve genital organs precisely because He foresaw that they would sin, and because it was His will that after the Fall, human beings should procreate through sexual intercourse. In response to this objection, Aquinas drew on another axiom, that nothing that properly belongs to human nature was acquired or lost due to the Original Sin of Adam and Eve - otherwise it could not be truly natural. But it is natural for human beings to procreate through sexual intercourse, as they are animals. Hence, the generative organs of Adam and Eve would have had a natural function, even if they had not sinned.

I answer that, Some of the earlier doctors, considering the nature of concupiscence as regards generation in our present state, concluded that in the state of innocence generation would not have been effected in the same way. Thus Gregory of Nyssa says (De Hom. Opif. xvii) that in paradise the human race would have been multiplied by some other means, as the angels were multiplied without coition by the operation of the Divine Power. He adds that God made man male and female before sin, because He foreknew the mode of generation which would take place after sin, which He foresaw. But this is unreasonable. For what is natural to man was neither acquired nor forfeited by sin. Now it is clear that generation by coition is natural to man by reason of his animal life, which he possessed even before sin, as above explained (97, 3), just as it is natural to other perfect animals, as the corporeal members make it clear. So we cannot allow that these members would not have had a natural use, as other members had, before sin.

(b) In his Summa Theologica I, q. 67, article 4, reply to objection 2. In this passage, Aquinas argues that even the continued existence of a thing in Nature which once had a purpose but now no longer has one, would suffice to make it "in vain," and that God could not have made anything like that.

The thing Aquinas is talking about is the luminous nebula, which some Christians believed God had made as the source of "light" on the first day in Genesis 1, and out of which the Sun had subsequently condensed on the fourth day. (This sounds like a striking anticipation of Laplace's nebular hypothesis.) Aquinas didn't like this idea. First, he rejected the proposal that the nebula turned into the sun on the fourth day, since then it would be transient, and Scripture is not meant to tell us about the production of transient things. Next, Aquinas considered the proposal that the nebula was still there, but that it was now so closely attached to the sun (which was made subsequently, on the fourth day) as to be visually indistinguishable from it. Aquinas rejected this suggestion too, since the nebula would then be superfluous after the fourth day, whereas "none of God's works have been made in vain."

Objection 2. Further, it is light that distinguishes night from day, and this is effected by the sun, which is recorded as having been made on the fourth day. Therefore the production of light could not have been on the first day.

Reply to Objection 2. In the opinion of some the light here spoken of was a kind of luminous nebula, and that on the making of the sun this returned to the matter of which it had been formed. But this cannot well be maintained, as in the beginning of Genesis Holy Scripture records the institution of that order of nature which henceforth is to endure. We cannot, then, say that what was made at that time afterwards ceased to exist.

Others, therefore, held that this luminous nebula continues in existence, but so closely attached to the sun as to be indistinguishable. But this is as much as to say that it is superfluous, whereas none of God's works have been made in vain. On this account it is held by some that the sun's body was made out of this nebula. This, too, is impossible to those at least who believe that the sun is different in its nature from the four elements, and naturally incorruptible. For in that case its matter cannot take on another form.

I answer, then, with Dionysius (Div. Nom. iv), that the light was the sun's light, formless as yet, being already the solar substance, and possessing illuminative power in a general way, to which was afterwards added the special and determinative power required to produce determinate effects. Thus, then, in the production of this light a triple distinction was made between light and darkness.

First, as to the cause, forasmuch as in the substance of the sun we have the cause of light, and in the opaque nature of the earth the cause of darkness.

Secondly, as to place, for in one hemisphere there was light, in the other darkness.

Thirdly, as to time; because there was light for one and darkness for another in the same hemisphere; and this is signified by the words, "He called the light day, and the darkness night."

From this, I deduce that Aquinas would have strongly opposed the Darwinist tenet that some living things possess vestigial organs which serve no function whatsoever, even though they once served a function in their ancestors - e.g. wing stumps in kiwi birds, or the blind eyes of cave fish.

I am of course aware that most of the vestigial organs identified by evolutionists are not completely functionless, but have a reduced functionality. But even if these organs are not completely "in vain," the complex structures found in these organs are in vain, according to Darwinists. For instance, the ostrich's wing serves certain functions, but a Darwinist would still argue that it possesses structures which are elaborate and functionless. However, Aquinas would disagree: God and Nature make nothing in vain, so the elaborate structures found in ostrich wings must serve a purpose, even now. Indeed, Aquinas says precisely this in his Commentary on Job, Chapter 39:

Because he [i.e. God, when addressing Job - VJT] had said already that she [the ostrich] has wings like the falcon and the hawk, (v.13) consequently, he shows next what purpose wings serve her saying, "When the time comes," when some necessity of violent movement presents itself to her, "she lifts her wings up high," so that although her body cannot be raised to fly by her wings, she is helped by her wings to run more swiftly, and so he says, "she laughs at the mounted horse," because she runs more swiftly than a horse carrying a man, "and his rider," of the horse, because she would run more swiftly than a man running on foot.

Modern biologists would not find this a terribly convincing answer; they would point out that wings that are only required for running need not possess the elaborate structures that the ostrich's wings have. In Part Two of my response to Professor Tkacz, I shall discuss how Aquinas might have responded to this objection, if he were alive today. For the time being, however, I would simply like to point out that Aquinas felt obliged to search for a purpose, because of his theological belief that God makes nothing in vain.

Here are a couple more cases where Aquinas uses the term "in vain" to mean "serving no current purpose," in his writings.

(c) In his Summa Theologica III, q. 9, art 4, Aquinas asks whether Jesus Christ had any acquired knowledge as a human being, and argues that of course He did. In the course of his argument, Aquinas writes:

But if in other things God and nature make nothing in vain, as the Philosopher says (De Coel. i, 31; ii, 59), still less in the soul of Christ is there anything in vain.

"The Philosopher" is of course Aristotle. Aquinas is quoting from his De Caelo (On the Heavens).

(d) Finally, in his Quaestiones Disputatae De Potentia Dei (Disputed questions on the power of God) Q. III art. VII, Aquinas asks: Does God work in the operations of nature? He rejects as "absurd" the view of some philosophers, now known as occasionalism, that natural agents do not really act. According to this absurd view, a flame does not really burn: rather, it is God who burns things whenever they happen to get too close to a flame. Since the flame has no action of its own, Aquinas argues that it would be devoid of purpose - a conclusion which Aquinas rejects:

It [occasionalism] is also contrary to reason which tells us that nothing in nature is void of purpose.

Other meanings of "in vain" in Aquinas:

(2) Unable to realize its purpose or natural end

In his Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 8, paragraph 91, where Aquinas enumerates arguments put forward by Aristotle that there can be no movement opposing the regular circular movement of the heavenly spheres, since if there were two mutually opposing movements pushing these spheres, the less powerful one would be in vain, and nature makes nothing in vain:

91. The second argument is at [47], and this argument is based on applying circular motion to natural bodies. And this is the argument: If one circular motion were contrary to another, then one of them would have to be in vain. But nothing in nature is in vain. Therefore, there are not two contrary circular motions ...

... For we say that a thing is 'in vain' when it does not realize its usefulness, as we say that a shoe is in vain if no one can wear it. In like manner, a body would be in vain, if it could not be moved with its proper motion; and likewise a motion would be in vain if nothing could be moved with it.

Consequently, it is plain that if there are two contrary circular motions, there would have to be something in vain in nature. But that this is impossible he now proves: Whatever exists in nature is either from God, as are the first natural things, or from nature as from a second cause, as, for example, lower effects. But God makes nothing in vain, because, since He is a being that acts through understanding, He acts for a purpose. Likewise nature makes nothing in vain, because it acts as moved by God as by a first mover, just as an arrow is not moved in vain, inasmuch as it is shot by the bowman at some definite thing. What remains, therefore, is that nothing in nature is in vain.

It should be noted that Aristotle here posits God to be the maker of the celestial bodies, and not just a cause after the manner of an end, as some have said.

Summa Contra Gentiles Book II, chapter 55, paragraph 13 (That Intellectual Substances Are Incorruptible):

It is impossible for natural desire to be in vain, 'since nature does nothing in vain.'

(3) Tending towards an unachievable goal

In his Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 12, paragraph 113, Aquinas gives an exposition of Aristotle's argument that the movement of a body in a straight line cannot possibly be infinite, because in such a case, a body would have a built-in tendency towards an unreachable goal (infinity), when moving upwards or downwards for instance; however, it is absurd to say that things in nature can tend towards unachievable goals. Here is Aquinas' commentary on Aristotle's argument:

113. He gives the second argument at [64] and it is this: A body that is moved up or down can reach the state of existing in such a place. This is clear from the fact that such a body is apt to be moved from the middle or to the middle, i.e., it has a natural inclination to this or that place. Now a natural inclination cannot be in vain, because God and nature do nothing in vain. Consequently whatever is naturally moved upward or downward can have its own motion terminated so as to be up or down. But this could not be, if the intermediate place were infinite. Consequently, the intermediate place is finite; so, too, is the body existing in it.

Therefore in summary he concludes from the foregoing that it is clear that no body can be infinite.

In a similar passage in his Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 13, paragraph 132, Aquinas explains why, according to Aristotle, it is impossible for a natural body to be infinite, because if it were, then it would have a built-in tendency to traverse an infinite distance, which is impossible, and it is absurd to say that things in nature can tend towards unachievable goals:

[132] ... The reason for this is that nature does nothing in vain. But it would be in vain for a thing to be tending to what is impossible for it to reach. Consequently, it is impossible for a thing to be locally moved to a place where it cannot arrive. But it is impossible to traverse an infinite place. If, therefore, places were infinite, there would be no motion. But since that is impossible, it cannot be that the parts of an infinite body of unlike parts be infinite in magnitude.

(4) Something which nothing aims for, tends towards, or strives to reach

In his Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 18, paragraph 183, Aquinas gives an exposition of Aristotle's argument that there cannot be many worlds. For Aristotle, there were three kinds of bodies: heavy bodies (earth and water), light bodies (fire and air) and weightless bodies (the heavenly bodies). Each of these kinds of bodies tends to occupy one of three kinds of places: a downward place (occupied by heavy bodies such as earth and water, both of which have a tendency to fall), the heavens (occupied by the celestial bodies, which are weightless) or an intermediate place (occupied by light bodies such as fire and air, which tend to rise upwards). But if there were other worlds, then they would have to be in a different kind of place, outside space as we know it, which no body of any kind has a natural tendency to occupy. This, Aristotle contends, is impossible.

Now, Aristotle anticipates that someone might object that a body - say, a light body, such as air - could conceivably occupy a different kind of place, not by nature, but in an unnatural fashion. Aristotle's response is that even if the place were unnatural for that kind of body, it would still have to be natural for some other kind of body. However, Aristotle insists that there can only exist three kinds of bodies in Nature (heavy, light and weightless), and these already have their allotted places. Consequently there can be no worlds outside our own universe, since if there were, they would occupy a space which no body had a natural tendency to occupy, and hence they would exist "in vain." Here is how Aquinas summarizes the latter part of Aristotle's argument:

183. But to this argument someone could object that the light body would be outside this intermediate place not according to nature but outside its nature. To exclude this he [Aristotle] adds that not even outside its nature can a light body be outside this intermediate place. Because every place that is outside nature for some body is according to nature for some other body. For neither God nor nature has made any place in vain, i.e., a place in which no body is apt to be. Now, no other body is found in nature except the three mentioned and to which the aforesaid places are deputed, as is plain from what has been said. Hence neither according to nature nor beside nature can a light body exist outside this intermediate place. Consequently, it is impossible that there be many worlds.

Where Professor Tkacz contradicts St. Thomas:

We've already seen that Professor Tkacz espouses a natural origin for all kinds of living organisms:

Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature.

Professor Tkacz also defended Darwinism as a scientific theory in the revised version of his talk to the Gonzaga Socratic Club:

The insights of Aquinas also provide an answer to the recent challenge to Darwinian evolution from ID theory.

I can only conclude that Professor Tkacz personally favors Darwinian evolution, as a scientific account of origins.

But if you accept the scientific premises of neo-Darwinism, you simply can't believe that God makes nothing in vain, or that nothing in nature is in vain. Dr. Douglas Theobald provides an excellent explanation of why evolutionists would expect vestiges to abound in Nature, in Part 2 (Past History) of his 29+ Evidences for Macroevolution: The Scientific Case for Common Descent in The Talk.Origins Archive, Version 2.87, 2007. Dr. Theobald points out that while vestigial organs may still possess (reduced) functions, "Vestigial characters, if functional, perform relatively simple, minor, or inessential functions using structures that were clearly designed for other complex purposes." Ostrich wings serve various functions, but "they are rudimentary wings which are useless as wings." "The specific complexity of the ostrich wing indicates a function which it does not perform, and it performs functions incommensurate with its complexity." And the blind eyes of cave-dwelling salamanders serve no purpose whatsoever. This is tantamount to saying that the eyes of cave-dwelling salamanders are in vain, and that the elaborate structure of the ostrich wing is in vain. No true Thomist could agree with that, for Aquinas insists that God and Nature make nothing in vain. And as we saw, Aquinas actually insisted that the ostrich wing is not in vain.

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A flock of domestic pigeons, each in a different phase of its flap. According to St. Augustine and St. Thomas Aquinas, every little detail of the wing of a bird was planned by God. But according to Professor Tkacz, God does not micro-manage anything in Nature; if He did that, He'd be cramping Nature's style.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

SHORT Version of "Smoking Gun" Number 15

"SMOKING GUN" Number 15:

GOD IS A MICRO-MANAGER. FOR EACH KIND OF CREATURE LIVING ON EARTH, EACH AND EVERY ONE OF ITS NATURAL FEATURES WAS PERSONALLY DESIGNED BY GOD.

According to Aquinas, God is a micro-manager: for each and every kind of organism in the natural world, each and every one of its characteristic features was personally designed by God. Hence none of the anatomical features which characterize different kinds of organisms are accidental.

Where Aquinas says this:

In Aquinas' Quaestiones Disputatae de Potentia Dei, Q. IV article II, reply to objection 22, Aquinas addresses the question: was matter formed all at once or by degrees? In the course of his lengthy reply, he declares that God made each and every kind of thing, in a perfect original state:

For God produced the first things in their perfect natural state, according as the species of each one required.

In his Summa Theologica I, q. 103 art. 5, Aquinas addresses the question: Whether all things are subject to the Divine government? First he lists some common objections to the idea that everything is subject to God's government. Then he approvingly cites the words of St. Augustine of Hippo, asserting that all the fine details of Nature had been planned by God:

On the contrary, Augustine says (De Civ. Dei v, 11): "Not only heaven and earth, not only man and angel, even the bowels of the lowest animal, even the wing of the bird, the flower of the plant, the leaf of the tree, hath God endowed with every fitting detail of their nature." Therefore all things are subject to his government.

Then he gives his own opinion:

I answer that, For the same reason is God the ruler of things as He is their cause, because the same gives existence as gives perfection; and this belongs to government. Now God is the cause not indeed only of some particular kind of being, but of the whole universal being, as proved above (q. 44, arts. 1, 2). Wherefore, as there can be nothing which is not created by God, so there can be nothing which is not subject to His government.

Finally, in his Summa Contra Gentiles Book III, chapter 76, paragraph 9 (That God's Providence applies immediately to all singulars), St. Thomas clearly declares God to be the ultimate micro-manager, who exercises providence even over individuals (or "singulars," as he calls them):

[9] Besides, if God does not immediately by Himself take care of these inferior singular things, this can only be either because He despises them or because His dignity might be lowered by them, as some people say. But this is unreasonable. It is indeed a matter of greater dignity to oversee the planning of the order for certain things than for it to be produced in them. So, if God works in all things, as we showed above, and if His dignity is not diminished thereby, and if this belongs rather to His universal and supreme power, it is in no sense something to be despised by Him, or something that might besmirch His dignity, if He exercises His providence immediately over these singulars.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz, on the other hand, believes that while Nature is wholly dependent on God for its existence, Nature runs on auto-pilot in its everyday operations. Creatures operate in accordance with their God-given natures. God does not micro-manage anything; if He did that, He'd be cramping Nature's style. Here's what Professor Tkacz said in his original talk given to the Gonzaga Socratic Club:

[M]odern Thomists distinguish between the existence of natural beings and their operations. God causes natural beings to exist in such a way that they are the real causes of their own operations...

Now, if this distinction between the being of something and its operation is correct, then nature and her operations are autonomous in the sense that nature operates according to the way she is, not because something outside of her is acting on her. God does not act on nature the way a human being might act on an artifact to change it. Rather, God causes natural beings to be in such a way that they work the way they do. ... Why are there such things as Hippopotamuses? Well, nature produced them in some way. What way did nature produce them and why does nature produce things in this way? It is because God made the whole of nature to operate in this way and produce by her own agency what she produces.

Professor Tkacz is also adamant that God does not "adjust" or manipulate Nature in any way, shape or form. As he put it in his article for the journal This Rock, Professor Tkacz wrote:

God does not intervene into nature nor does he adjust or "fix up" natural things.... Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature.

Once again, the Professor and his philosophical master, St. Thomas Aquinas, are poles apart in their thinking.

Part One (Short version) Part Two Part Three Part Four Part Five