St. Thomas Aquinas and his Fifteen Smoking Guns (Part One of a five-part reply to Professor Tkacz)

Part Two Part Three Part Four Part Five
Part One (Long version)
For some time now, I've been threatening to publish an expose of the pretentious claims of self-styled "Thomists" who have argued that Intelligent Design is completely at odds with St. Thomas Aquinas' philosophy. Well, this is it. The Big One. Get ready, and hold on to your hats.

In today's post, I'm going to comprehensively rebut a paper by a leading "Thomistic" critic of Intelligent Design, who contends that Thomists have nothing to fear from the scientific claims of Darwinism. I'm going to show that this ID critic actually contradicts what St. Thomas Aquinas wrote on the topic of origins, on no less than fifteen specific points (yes, fifteen!), which I shall call Aquinas' "fifteen smoking guns." I think my readers will agree with me that a "Thomist" who contradicts his master (St. Thomas Aquinas) on no less than fifteen substantive points can hardly be considered a true Thomist.

One of the smoking guns (number 10) will be of special interest to UD readers, as it reveals an Intelligent Design-style argument in the writings of Aquinas himself!

In this post, I've decided to take on Professor Michael Tkacz, Associate Professor of Philosophy at Gonzaga University. A few years ago, he gave a talk entitled, Thomas Aquinas vs. The Intelligent Designers: What is God's Finger Doing in My Pre-Biotic Soup? to the Gonzaga Socratic Club, which has been made available as a paper on the Internet. In 2008, a slightly modified version of Professor Tkacz's paper was published as an article entitled, Aquinas vs. Intelligent Design, in the journal This Rock. I'll be commenting on both Professor Tkacz's original talk and his article for "This Rock."

I've divided my reply to Professor Tkacz into five major parts. Part One deals with Aquinas and Darwinism. My aim is to demonstrate conclusively that the teachings of St. Thomas Aquinas are fundamentally incompatible with Darwinism. I'm going to list fifteen statements (or theses) which summarize what Aquinas taught on the creation of the cosmos and the origin of living things. I will also show that Professor Tkacz disagrees with every one of these statements, and I'll explain why no card-carrying Darwinist could agree with these statements either.

In Part Two, I shall argue that there are four key features of Aquinas' philosophy which are totally at odds with Darwinism. You can't be a Thomist and a Darwinist, of any stripe.

In Part Three, I aim to show that Aquinas' views on the interpretation of the Bible would have been enough to prevent him from becoming a Darwinist, even if he had had no objections to Darwinism in principle.

Part Four will specifically address the arguments put forward against Intelligent Design in Professor Tkacz's paper. This part could be called my "reply proper" to Professor Tkacz. In this part, after making some general comments about the paper, I'll demonstrate that it misrepresents Intelligent Design in four major ways. After that, I'll identify what I see as five major flaws in Professor Tkacz's paper.

In Part Five, I'll argue that Intelligent Design fulfils a vital theological role: it elucidates what it means to say that God (the Necessary Being) is intelligent, and also how we can know that God is intelligent. Finally, I'll conclude with a discussion of the real reason why some people don't like Intelligent Design. The answer, I shall argue, is that they have a deficient concept of beauty.

Also, in my reply to Professor Tkacz, I'm going to open not one, but seven theological cans of worms. I'm not being mischievous here. I'm opening these "cans of worms" in order to help foster productive dialogue between Intelligent Design theorists and theistic evolutionists on the following topics:

(a) the way in which God interacts with the world. In particular, does God co-operate with each and every natural agent whenever it acts, making God an immediate cause of each change that occurs in the natural world? If you're inclined to answer "Yes," then you're a concurrentist (a term I'll explain below), like most Christian theologians down through the ages, and you'll find Intelligent Design a lot more congenial than people who view God as merely a remote cause of effects produced in Nature.

(b) the limits of God's omnipotence. I'm going to suggest that even an omnipotent Deity can't make a predictable universe that can naturally generate life in all its diversity, and that only a "hands-on," manipulating Deity can reliably generate the life-forms we see on Earth today.

(c) what it means to say that God is intelligent. Specifically, can God's intelligence be characterized in purely teleological terms? When we say that God understands His creatures, do we simply mean that He is capable of guiding all His creatures towards their built-in ends, which He assigned for them? Or do we mean something more - namely, that God has concepts which specify the form as well as the finality of the creatures He has made, and which God is capable of articulating in language?

(d) the possibility of knowing the Mind of God. No-one can fully comprehend God, as He is infinite. However, I'm going to argue that God is by nature the kind of Being who wants to be understood by His intelligent creatures, insofar as they are able to do so, and that it's reasonable to expect that He would have left clues in Nature that we are capable of discovering, revealing the manner in which He made the cosmos, and also how He produced life on Earth, in all its complexity. We should be able to look back in time and figure out what happened when.

(e) the perfection of God's handiwork. Were all biologically complex structures made perfectly, or do they contain inherent imperfections? Is the vertebrate eye perfect, and if so, in what sense? What about our DNA? The Bible says that all of God's works are perfect (Deuteronomy 32:4), and Aquinas taught the same thing, repeatedly, in his writings. But according to neo-Darwinists, imperfection is rife in Nature. Who's right?

(f) the question of exactly which features of the natural world were planned by God. For instance, did God plan the laryngeal nerve of the giraffe, the "pseudo-genes" in our DNA, and the emergence of the malaria parasite? I will prove that St. Augustine of Hippo and St. Thomas Aquinas both taught that God is a micro-manager, who planned every feature of living things down to the smallest detail. That puts them at odds with neo-Darwinists, who are committed to asserting that many features of our genes and our anatomy are accidental. It also puts them at odds with Professor Tkacz, who regards the scientific claims of neo-Darwinism as totally compatible with "modern Thomism."

(g) the real reason why many Christians don't like Intelligent Design. Many people (including some Christians) have a two-dimensional concept of beauty: something is beautiful if it combines the attributes of variety, or plenitude (which makes it interesting) and simplicity of underlying principles, or economy (which makes it easily comprehensible). That's why these people like Darwinism: it's a simple theory that purports to account for life in all its diversity. By contrast, Intelligent Design strikes them as messy, because it says that life cannot be reduced to a few simple principles: living things contain irreducibly complex systems, which have to be specified in detail, as does the code in our genome. But the beauty inside the cell, I shall argue, is more like the beauty of a story, as it contains a message written by its Author. We need a third dimension to describe this kind of beauty.

Why have I targeted Professor Tkacz?

I have chosen to focus on Professor Tkacz's paper on Aquinas and Intelligent Design, not only because it is lucidly written, highly readable and admirably concise, but because it continues to be very influential in anti-ID circles. Two prominent Thomists who have recently cited the paper are Professor Edward Feser, a Catholic philosopher and a critic of Intelligent Design (see here) and Professor Francis Beckwith, a Catholic philosopher who has also published articles attacking ID. Professor Beckwith lists several other essays critical of Intelligent Design here. In this post, I shall endeavor to show that the trust that these two Thomists reposed in Professor Tkacz as a reliable exponent of Aquinas' teaching on the creation and on the origin of living things is utterly misplaced.

Another reason why I chose Professor Tkacz's paper is that it contains nearly every erroneous charge hurled at the Intelligent Design movement by theistic evolutionists. I'm not saying that as a criticism, but as a compliment: Professor Tkacz's paper is at least comprehensively wrong.

I will definitely be pulling no punches in my reply to Professor Tkacz, but I would like to emphasize at the outset that I do not doubt his personal sincerity or his orthodoxy, even though I would contend that he has badly mis-read St. Thomas Aquinas. And although I might argue that some of his principles may have dangerous theological implications if taken to their logical conclusion, this in no way implies that I am imputing any theologically dangerous views to Professor Tkacz himself.

A few short remarks about myself

Let me declare up-front that although I would describe myself as a philosopher in the Aristotelian-Scholastic tradition, whose thought is heavily influenced by St. Thomas Aquinas, I make no claim to being a Thomist, unlike Professor Tkacz. So I won't hesitate to criticize Aquinas' arguments if I think they're not up to scratch. However, I'm old-fashioned enough to believe that if you're going to call yourself a Thomist, then you should follow your master, St. Thomas Aquinas. A Thomist who contradicts his master on no less than fifteen vital points, as Professor Tkacz does, is not a Thomist, in my book.

Many readers will be aware that I have a Ph.D. in philosophy, and that I first started studying Aquinas' philosophy back in 1979. Nevertheless, some readers may reasonably object, "But you're not an academic. Why should we trust you as an exponent of authentic Thomism, over Professor Tkacz?" My answer is: don't trust me. Judge for yourselves. Unlike Professor Tkacz, I'll be quoting very extensively from the writings of St. Thomas Aquinas. Readers only need to click on my hyper-links to ascertain whether I'm quoting him fairly and accurately. By the end of Part One, I think every fair-minded reader of this post will agree with my contention that Thomism and Darwinism don't mix, period. Even readers who reject Intelligent Design will be forced to acknowledge this point: the evidence is simply overwhelming, and readers can easily verify it for themselves. Part Two of my reply encapsulates, in a nutshell, why you can't be a Thomist and a Darwinist, and answers several objections which I anticipate theistic evolutionists might wish to raise against my key argument, while in Part Three I shall endeavor to show that St. Thomas would have rejected neo-Darwinian evolution on Scriptural grounds alone, even if he'd had no theological objections to Darwinism.

Part Four of my reply, in which I directly respond to Professor Tkacz's paper, is aimed especially at thoughtful theistic evolutionists. I hope to convince some of them that we in the Intelligent Design movement have thought long and hard about our philosophical position, that we are capable of answering the best objections that can be raised against it, that theistic evolution is vulnerable to difficulties of its own, and that Thomism cannot help theistic evolutionists to address these difficulties. In Part Five, I go further, and argue that Intelligent Design is essential, in order to mount an effective defense against modern skeptical arguments relating to what it means for God to be intelligent.

Regarding the question of origins, I personally believe in an old cosmos, created approximately 14 billion years ago, and I believe that all living things are descended from a common ancestor that lived around four billion years ago. I'm also favorably impressed with the recent research conducted by Dr. Douglas Theobald, of Brandeis University, confirming the common ancestry of all living things in the first large-scale, quantitative test across all three domains of organisms. However, I believe that the first living thing itself, as well as each of the 1,000+ families (or in some cases, super-families) of living things, plus the hundreds (maybe thousands) of irreducibly complex structures in the cells of living things, were all designed by God, and that He produced these phenomena by manipulating Nature. (Some Intelligent Design proponents think that God could have programmed the universe to produce these complex forms at the Big Bang, but I don't think that's possible, for reasons I'll explain in Part Four of my post - see "Fatal Flaw" number 4.)

Please note that I'm not claiming that Aquinas would hold my views on origins, if he were alive today. In fact, I shall argue in Part Three that he'd probably be an old-earth creationist, if he knew what scientists know now; however, he would certainly need to apply his principles for interpreting Scripture in a very creative fashion, in order to reconcile the genealogies in Genesis with modern scientific estimates of the antiquity of the human race. But of one thing I am certain: there's no way Aquinas would be a Darwinist, if he were alive today.

Terminology and my use of emphases - a few clarifications

For the sake of clarity, I'm going to capitalize the word "Nature" in this post, when referring to the natural order as a whole, and I'll use lower case when referring to the nature of a specific creature - e.g. "human nature," or "the nature of a hippopotamus." Professor Tkacz generally employs lower case in his article for both usages, so I'll quote him accordingly.

In this post, I'm going to use the word "create" to refer exclusively to: (i) the act of bringing something into existence ex nihilo, i.e. without using any raw material; or (ii) the act of conserving something in being, which would cease to exist otherwise. That's how Aquinas uses the word, and that's how Professor Tkacz uses it too. Creation, defined in this way, is God's prerogative.

I'm going to use the word "produce" to refer to the act of making something (or more precisely, its form), using pre-existing matter. Of course God can produce things; He is almighty; but finite agents (such as human beings) are capable of producing things too. And as we'll see, Aquinas generally uses the word "produce" when talking about God forming the first creatures from pre-existing matter, by His own immediate power. I'll also be using the word "generate", with a meaning equivalent to "produce." Generation may be either natural or supernatural.

Finally, I'm going to use the word "make" in a very general sense, which includes both the terms "create" and "produce." The verb "make" may refer to the act of bringing something new into existence, with or without the use of pre-existing matter. That "something" may be either a new form (which can only be made if there is pre-existing matter) or a new thing (which can be made without any pre-existing matter at all). More broadly, the word "make" may also refer to the act of maintaining a form in existence, or the act of conserving a thing (composed of form plus matter) in existence.

Readers should also note that in this post, all emphases in my citations from the writings of St. Thomas Aquinas, Professor Michael Tkacz and other authors are entirely my own.

PART ONE - Table of Contents

Section 1: AQUINAS' FIFTEEN SMOKING GUNS! - Summary

Section 2: AQUINAS' FIFTEEN SMOKING GUNS! - Aquinas vs. Tkacz, with brief hyper-linked quotations from both authors, showing that Professor Tkacz contradicts Aquinas on each point

Part One of my reply to Professor Tkacz is divided into two sections:

SECTION ONE: AQUINAS' FIFTEEN SMOKING GUNS! (Summary)
Section One is as brief as I can make it: about 4,700 words long. It's an "executive summary" of Aquinas' teachings on origins, written for people who don't like reading long posts. Basically it's a short list of fifteen statements or theses that I've put together from the writings of Aquinas, which summarize his views on origins. In the interests of brevity, there will be no citations from Aquinas in this section; they're in Section Two.

SECTION TWO: AQUINAS' FIFTEEN SMOKING GUNS - Aquinas vs. Tkacz, with brief hyper-linked quotations from both authors, showing that Professor Tkacz contradicts Aquinas on each point.
Section Two is about 20,000 words long. However, it's well worth reading, not only for Thomists, but also for people who are interested in the history of big ideas.

Section Two provides supporting quotations from Aquinas for each of these fifteen statements listed in Section One, with references and hyper-links to Aquinas' online works. The quotations from Aquinas in this section are fairly brief, but readers can check the context for themselves using the hyper-links I've provided. I've also included links to a longer version of Aquinas' fifteen "Smoking Guns," showing the quotations in their full context. The longer version is written for scholars and serious students of Aquinas, who may wish to verify that I've represented his teachings faithfully and accurately. However, I would suggest that they might like to read up to the end of Section One first, in order to get a brief overview of Aquinas' fifteen "smoking guns," before having a look at the longer version. In Section Two, I have also appended brief excerpts from Professor Tkacz's original talk to the Gonzaga Socratic Club, as well as the revised version of his talk that was published in the journal This Rock in 2008. My aim here is to show that Professor Tkacz contradicts all fifteen of the statements taught by Aquinas - explicitly in most cases, and implicitly in the remaining cases.

So without further ado, here are Aquinas' fifteen smoking guns!

First of all, for those who want "the beef" right up-front, here's a very short list of Aquinas' fifteen "smoking guns." As I will show, these points were all explicitly taught by Aquinas. However, Professor Tkacz denies all fifteen of these points, either explicitly or implicitly.

Physical effects requiring a supernatural cause are the best possible way of demonstrating God's power and free agency.
(The conclusion I draw is that St. Thomas would have therefore highly commended so-called "God of the gaps" arguments, so long as they convincingly demonstrate that some effect which we perceive in the world around us is beyond the power of Nature to produce.)
God can (and sometimes does) produce effects in Nature without using natural agents.
Some physical changes are beyond the power of Nature to bring about: they can only be produced by God.
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.
God is an immediate cause of each and every effect occurring in the natural world. Whenever God works in co-operation with a natural agent to produce an effect, the natural agent is also an immediate cause, but it operates as an instrument of God, Who is the Principal Agent. (Concurrentism.)
A thing doesn't need to have a natural origin, in order to belong to a natural kind.
Nature always works in the same regular, repeatable way when producing each kind of thing: it needs the right kind of stuff to work on, plus an agent of adequate causal power, in order to generate the form of that kind of thing. (Hyper-uniformitarianism.)
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 occasionally give rise to new kinds of creatures, but one kind of creature can never "change into" another, over time. (Essentialism.)
The first animals that were capable of reproducing according to their kind must have been produced immediately by God, and God alone. (Supernatural production of the first animals.)
The "higher," more complex animals must have been produced immediately by God, and God alone.
The bodies of the first human beings must have been produced immediately by God, and God alone.
Language, no matter where it is found, is a hallmark of intelligence.
(The conclusion I draw is that if we find effects in Nature that are written in some sort of language, we can be sure that an Intelligent Being produced them. In particular, since we now know that there is a suite of programs running within the cells of each living organism, then St. Thomas Aquinas, if he were alive today, would unhesitatingly declare that an intelligent agent must have produced these programs, and not some physical process.)
All of God's works are perfectly designed in relation to their ends. Hence there are no bad designs in Nature.
Everything that God made has a purpose; and everything in Nature has a purpose. Hence organisms contain no redundant or vestigial features.
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.

St. Thomas Aquinas. Detail from a painting by Fra Angelico (1395-1455).

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SECTION ONE: AQUINAS' FIFTEEN SMOKING GUNS! (Summary)

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. I'll be providing documentation from the writings of Aquinas in Section Two below, as well as proof that Professor Tkacz rejects each and every one of these statements by Aquinas.

"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.

Professor Tkacz, on the other hand, regards the contingency and orderliness of the natural world as the best evidence for God's existence. Aquinas certainly held that these features of the natural world can be used to establish God's existence, but he also regarded events occurring outside the order of nature as the best possible manifestations of God's power and voluntary agency. However, Professor Tkacz derides appeals to supernatural effects as "God of the gaps" arguments, which he considers to be at odds with the authentic tradition of the Church.

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"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.

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." God maintains things in being, but they operate by themselves, in the way God intended them to. Professor Tkacz also asserts that "God does not intervene into nature nor does he adjust or 'fix up' natural things." That's about as far from Aquinas' position as you can get.

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"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 supernatural explanation: they 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. (However, Aquinas also mistakenly believed that some of the lower animals were capable of being generated spontaneously, without "seed," from dead or decaying matter, and that these animals need not have been produced by God, in the beginning.)

Professor Tkacz, by contrast, asserts that "God does not intervene into nature nor does he adjust or 'fix up' natural things." He also claims that for "any given feature of living organisms," "there must exist some explanatory cause in nature." These statements are diametrically opposed to Aquinas' position.

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"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 its operations: 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.

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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"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 agent to produce an effect, the natural agent 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. In other words, God really does "reach into" nature's operations.

Aquinas' concurrentism is an especially important issue for this post: if Aquinas is correct here, 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.

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"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 from pre-existing matter would still be a hippopotamus, and a human being produced immediately by God would still be a human being. (Likewise, 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.)

Professor Tkacz, on the other hand, 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. As he puts it:

[N]atural 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.... 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.

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"SMOKING GUN" Number 7: Nature always works in the same regular, repeatable way when producing each kind of thing: it needs the right kind of stuff to work on, plus an agent of adequate causal power, in order to generate the form of that kind of thing. (Hyper-uniformitarianism.)

Aquinas believed in an extreme form of uniformitarianism, which I'll call hyper-uniformitarianism. He thought that each kind of thing in Nature is always 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.

(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.

Professor Tkacz appears to deny that the processes giving rise to complex organisms are scientifically replicable, when he asserts that "The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

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"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 occasionally give rise to new kinds of creatures, but one kind of creature can never "change 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.

(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. 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).

(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 separate 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 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 (e.g. one family of coelacanth fish) still exist today. 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.

Professor Tkacz, on the other hand, writes:

Many who oppose the standard Darwinian account of biological evolution [mistakenly] 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 appears that Professor Tkacz would be unperturbed if there proved to be no sharp discontinuities between the different "kinds" of living things in nature. Unlike Aquinas, Professor Tkacz has no philosophical commitment to essentialism, and no problem with "the standard Darwinian account of biological evolution," as a scientific theory.

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"SMOKING GUN" Number 9: The first animals that were capable of reproducing according to their kind must have been produced immediately 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.

Professor Tkacz, on the other hand, writes:

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.

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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"SMOKING GUN" Number 10: 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, sothey could not have evolved from other living organisms either.

Professor Tkacz, on the other hand, writes:

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 that the forms of complex animals must have been immediately produced by God.

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"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.

Professor Tkacz, on the other hand, maintains: "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's thinking and that of Aquinas are poles apart.

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"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 have more to say about these cellular programs in Part Five of my reply to Professor Tkacz.)

Professor Tkacz, on the other hand, maintains: "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. As he puts it: "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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"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 that God 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.

Professor Tkacz, on the other hand, asserts that "there must exist some explanatory cause in nature" for "any given feature of living organisms," and he also writes:

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 theory. However, 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." As Professor John Avise puts it in a recent PNAS article (May 5, 2010, doi: 10.1073/pnas.0914609107) entitled Footprints of nonsentient design inside the human genome:

[M]any complex biological traits are gratuitously complicated, function poorly, and debilitate their bearers.

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

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"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.

According to Aquinas, every feature of living things exists for a purpose.

Aquinas repeatedly insists that "God creates nothing in vain," that "nothing is void in God's works," and that "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.

Professor Tkacz, on the other hand, seems to personally favor Darwinian evolution as a scientific theory, as we saw above. 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. Vestiges, if genuine, would be either wholly in vain (e.g. the blind eyes of cave-dwelling salamanders) or partly in vain (e.g. the elaborate but useless structures found inside ostrich wings, whose functionality is reduced, compared to that of their ancestors, who could fly). However, no true Thomist could agree that the eyes of cave-dwelling salamanders are in vain, and that the elaborate structure of the ostrich wing is in vain, as Aquinas repeatedly insists that God and Nature make nothing in vain.

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"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.

Aquinas asserts that "God produced the first things in their perfect natural state, according as the species of each one required," and he approvingly cites St. Augustine's statement: (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." He also insists that God exercises immediate providence over individual things (or singulars, as he calls them), and insists that "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."

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. He writes that " God causes natural beings to be in such a way that they work the way they do," 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," and that "God does not intervene into nature nor does he adjust or 'fix up' natural things." God did not micro-manage the origin of species, either: "The most complex of organisms have a natural explanation."

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

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SECTION TWO: AQUINAS' FIFTEEN SMOKING GUNS! - Aquinas vs. Tkacz, with brief hyper-linked quotations from both authors, showing that Professor Tkacz contradicts Aquinas on each point

Scholars wanting to read the long version, with all quotes are given in their full contexts, can do so by clicking here: Aquinas' Fifteen Smoking Guns - Long Version.

I have placed hyper-links in front of each of the fifteen points, so as to allow readers to navigate from one point to another as easily as possible.

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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
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

LONG 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). Here's the key excerpt:

[D]ivine 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.

Here, Aquinas says that God's power and voluntary agency "can be manifested in no better way ... than by the fact that He sometimes does something outside the order of nature." I conclude that he would have had no qualms whatsoever about appealing to supernatural effects, in order to convince skeptics of God's existence.

See also Summa Contra Gentiles Book III, chapter 99, paragraphs 1 and 2 (That God can work apart from the order implanted in things, by producing effects without proximate causes). I shall discuss these passages in "Smoking Gun" number 2 below.

Where Professor Tkacz contradicts St. Thomas:

Professor Tkacz regards the contingency and orderliness of the natural world as the best evidence for God's existence. Now, Aquinas did indeed argue that God's existence could be demonstrated from the radical contingency of Nature, as well as from the goal-directed behavior we find throughout the natural world. In his Summa Theologica I, q. 2, art. 3 (Whether God exists), Aquinas put forward five ways of establishing God's existence. The Third Way deals with contingency and necessity, and the Fifth Way with the built-in tendency of things to behave in a goal-directed fashion. An earlier version of these two arguments can be found in Aquinas' Summa Contra Gentiles Book I, chapter 13, paragraphs 25 and 35 (Arguments in proof of the existence of God). However, Aquinas 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:

Without order and design in nature, then, there cannot be natural science. So, the followers of Darwin who argue that evolutionary theory removes all need for positing a design in nature are inconsistent. Presumably, they make this claim on the basis of natural science which, if their claim is true, is impossible.
Moreover, as Aquinas argued in the Summa Theologica many centuries ago, the presence of chance and contingency in nature shows that nature requires a divine Creator in order to exist (I:2:3). Again, the Darwinians, who place so much weight on the role of chance in nature, are inconsistent to deny the creation of nature....
[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 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.

"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

LONG 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, where Aquinas addresses the question: 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 ... [S]ince 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...

(2) In his Summa Theologica I, q. 105 art. 2, Aquinas asks whether God can move a body immediately. He responds:

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.

(3) In his Summa Contra Gentiles Book III, chapter 99, paragraphs 1 and 2 (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...

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

I answer that, without any doubt God can work in creatures independently of created causes ... 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.

"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

LONG 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 supernatural explanation: they 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. (However, Aquinas also mistakenly believed that some of the lower animals were capable of being generated spontaneously, without "seed," from dead or decaying matter, and that these animals need not have been produced by God, in the beginning.)

Where Aquinas says this: In his Summa Theologica I q. 91, article 2, reply to objection 3 (Whether the human body was immediately produced by God?), where Aquinas refers to "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."

In his Summa Theologica I, q. 92 art. 4(Whether the woman was formed immediately by God?) Here's a brief excerpt:

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 II chapter 43, paragraph 6 (That the distinction of things is not caused by some secondary agent introducing forms into matter). Here, Aquinas argues that the forms of the very first animals "must of necessity proceed from the Creator alone" - at least, for those animals that are "generated only from seed."

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
"SMOKING GUN" Number 8 Number 9 Number 10 Number 11 Number 12 Number 13 Number 14 Number 15

LONG 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.

Where Aquinas says this:

(Note: A more in-depth discussion of Aquinas' views on angels can be found in the long version of Aquinas' Fifteen "Smoking Guns.") What follows here is a slightly simplified version of Aquinas' argument.

Aquinas' statements above can be grouped under five main headings:

1. Lower (terrestrial) bodies are moved by celestial bodies

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.

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] ... 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... Therefore, the heavens must be the cause of all motion in these lower bodies.

2. The heavenly bodies are moved by intelligent beings

Summa Contra Gentiles Book III, chapter 78 (That other creatures are ruled by God by means of intellectual creatures):

[1] Since it is the function of divine providence to maintain order in things, and since a suitable order is such that there is a proportional descent from the highest things to the lowest it must be that divine providence reaches the farthest things by some sort of proportion. Now, the proportion is like this: as the highest creatures are under God and are governed by Him, so the lower creatures are under the higher ones and are ruled by them. But of all creatures the highest are the intellectual ones, as is evident from what we said earlier. Therefore, the rational plan of divine providence demands that the other creatures be ruled by rational creatures.

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.

At this stage, Aquinas' argument is still incomplete. All he has shown is that some intelligent being or beings move the heavenly bodies. As he goes on to acknowledge in paragraph 12 of the passage quoted above, this being could be God, moving these bodies by Himself, or alternatively, there could be some intermediate agents (i.e. angels) created by God, who move the heavenly bodies. Moreover, these angels may be completely separate from the bodies they move; or they may be united to these bodies in some way. In order to demonstrate that the angels move the heavenly bodies as their instruments, Aquinas has to demonstrate that there must exist intelligent beings in the universe which are immaterial and not attached to any kind of body. Let's have a look at his arguments.

3. There must exist some intelligent beings which are bodiless and utterly immaterial

Summa Contra Gentiles Book II, chapter 46 (That the perfection of the universe required the existence of some intellectual creatures):

[4] Moreover, in order that creatures might perfectly represent the divine goodness, it was necessary, as we have shown, not only that good things should be made, but also that they should by their actions contribute to the goodness of other things. But a thing is perfectly likened to another in its operation when not only the action is of the same specific nature, but also the mode of acting is the same. Consequently, the highest perfection of things required the existence of some creatures that act in the same way as God. But it has already been shown that God acts by intellect and will. It was therefore necessary for some creatures to have intellect and will.

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. ... 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.

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].
[11] Excluded hereby are the error of the Sadducees, who said that "no spirit exists" (Acts 23:8); the doctrine of the natural philosophers of old, who maintained that every substance is corporeal; as well as the position of Origen, who held that no substance, save the divine Trinity, can subsist apart from a body; and, indeed, of all the other thinkers who hold that all the angels, both good and bad, have bodies naturally united to them.

4. These bodiless intelligent beings (also known as separate substances, or angels) move the heavenly bodies with their intellects, and use them as their instruments

Summa Contra Gentiles Book II, chapter 100 (That Separate Substances Know Singulars - i.e. Angels have a knowledge of particular bodies (VJT)):

[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.

5. The angels move the heavenly bodies in order to regulate the generation of living things on Earth - the end of which is man

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.
... [C]elestial 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.

Where Professor Tkacz contradicts St. Thomas:

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

LONG 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.

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 Two 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 below, Professor Tkacz is a conservationist. Aquinas, however, 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.

In his writings, Aquinas mainly addresses the first sense of the word "immediate," and it is this that I shall discuss here. Readers who would also like to see evidence that Aquinas maintained that causal agency was immediate in the second sense should consult the long version of "Smoking Gun" Number 5, where I present evidence from Aquinas' discussion of the miracle of the three young men in the fiery furnace (Daniel 3:26-27).

Where Aquinas says all this:

Here are the relevant quotes from St. Thomas Aquinas himself, which conclusively establish that he was a concurrentist. They come from two sources:

(1) Aquinas' Quaestiones Disputatae De Potentia Dei (Disputed Questions Relating to the Power of God) Q. III art. VII (Does God work in the operations of Nature?) Note: this is a very long article. I'll just give a few very brief quotes here. I address this question in considerably more depth, in the LONG Version of "Smoking Gun" Number 5, which Aquinas scholars might want to check out.

...God causes the action of every natural thing by moving and applying its power to action...

...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...

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) Aquinas' Summa Contra Gentiles Book III, chapter 70, reply 1 and reply 3 (i.e. paragraphs 5 and 7) (How the same effect is from God and from a natural agent):

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 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.

Spoken like a true concurrentist!

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.

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 flavor 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 holds (as Aquinas does) that God maintains all creatures in being as the Author of their natures, but who (unlike Aquinas) 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 Four 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

LONG 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.

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 so as 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 (Whether woman should have been made from man?), Aquinas explains that God, being infinite, was perfectly capable of producing the first man from slime and the first woman from Adam's rib:

[T]he 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.

In his Summa Theologica I, q. 92 art. 4 (Whether the woman was formed immediately by God?) Here's a brief excerpt:

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):

... 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:

[5] ...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.
[7] ...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

LONG 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.

The foregoing points have two very significant corollaries:

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.

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

Where Aquinas says 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.

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 "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."

(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: "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."

In his Summa Theologica I q. 19 art. 4 (Whether the will of God is the cause of things) (see the sentence, "This is shown, secondly, from..."), Aquinas describes "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."

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 writes 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.""

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.

(Note to the reader: Aquinas generally used the term "seed" (or "semen") to refer to the formative agent that kick-started the development of the embryo. However, he sometimes also used the term "seed" to refer to the matter out of which the embryo was formed, as in the passage cited above. He expressly confirms this 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.

This explains Aquinas' 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 - which is why the Aquinas had no problem accepting the virginal conception of Christ:

[7] ... 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.

Objection:

In his Summa Contra Gentiles Book IV, chapter 45, paragraph 7, Aquinas states that air can be generated from water and also from earth - in other words, from two different elements. Thus according to Aquinas, the same effect (air) can result from two different kinds of matter.

Reply:

For Aristotle and for Aquinas, the elements were not irreducibly distinct from each other, but inter-convertible. Hence they were not two different kinds of matter. For an interesting essay on the subject, I refer the reader to Carmen Giunta's online text, Elements and Atoms: Case Studies in the Development of Chemistry, and especially to the first chapter, Four Elements: Aristotle, De Generatione et Corruptione.

In his Summa Contra Gentiles Book III chapter 102, paragraph 5 (That God alone works miracles), Aquinas writes:

[J]ust 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.

In his Summa Theologica I, q. 71 art. 1, reply to obj. 1 (The Work of the Fifth Day), Aquinas argues that "seed" (from the male parent) is the only natural agent with sufficient power to generate certain kinds of animals. For the generation of some of the "lower" animals, he believed (like most of his contemporaries) that movement of the heavenly bodies, acting on decaying matter, was sufficient:

...[N]ature produces its effects by determinate means, and consequently, those [living] 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, arguing that "those things that happen by chance, happen only rarely [as] we know from experience", so Empedocles' theory is unable to account for the fact that "harmony and usefulness are found in nature either at all times or at least for the most part," which, he says "cannot be the result of mere chance."

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

LONG 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 noted evolutionary thinker and biologist 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.

(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. 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).

(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) God produced the first living creatures, according to their separate 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, 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. 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 his essay), 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.

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":

...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...

Aquinas also asserts the unchangeability of species in his Quaestiones Disputatae De Potentia Dei (Disputed Questions on the Power of God), Question V, article IX, reply to the Third Objection (Will Plants, Animals and Minerals Remain After the End of the World?), Aquinas declares that each species will remain in existence as long as the heavenly bodies (which regulate Nature) keep moving - that is, until the end of the world:

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.

Aquinas makes his 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.

In Aristotle's account of reproduction, from which Aquinas drew, 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.)

Thus 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).

Since most animals reproduce sexually and breed true to type, Aquinas' definition of animals "generated from seed" would apply to the vast majority of animals, although his second condition would have to be modified (in the light of modern scientific knowledge) to include reference to the active role played by both the female and the male, in generating the form of their offspring.

Aquinas generally used the term "seed" (or "semen") to refer to the formative agent that kick-started the development of the embryo, but he sometimes also used the term "seed" to refer to the matter out of which the embryo was formed. 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.

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, as we saw in "Smoking Gun" number 7. 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 (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.

In his Commentary on Aristotle's Physics, Book II, lecture 7, paragraph 204 (Different opinions about fortune and chance, the hidden causes), Aquinas asserts that many kinds of plants and animals can only be generated from the right kind of seed (which can only come from a parent of the same kind):

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 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:

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.

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] ... 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.

(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.

In his Summa Theologica I, q. 72 art. 1, reply to obj. 3 (The work of the sixth day), where he discusses the works of the sixth day in the Genesis account, Aquinas writes: "In other animals, and in plants, mention is made of genus and species, to denote the generation of like from like."

In his Commentary on Aristotle's Physics, Book II, lecture 7, paragraph 204 (Different opinions about fortune and chance, the hidden causes), Aquinas 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, objection 3, where he addresses the question of whether the completion of the Divine works ought to be ascribed to the seventh day in Genesis 1, as new species are still appearing. 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:

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. ... 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. ... 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) God produced the first living creatures, according to their separate kinds.

In his Summa Contra Gentiles Book II, chapter 43, paragraph 10 (That the distinction of things is not caused by some secondary agent introducing forms into matter), Aquinas states that "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."

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

LONG 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 makes his argument in two places in his writings. (Note for scholars: a much fuller treatment of these texts can be found in the longer version of my online article, "Aquinas and his Fifteen Smoking Guns.")

Firstly, 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 (namely, those that are "naturally generated from seed") could only be generated by two parents of the same kind breeding true to type, and if these kinds of 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: "at the first beginning of the world the active principle was the Word of God, which produced animals from material elements."

Secondly, in his Summa Contra Gentiles Book II, chapter 43, paragraph 6 (That the distinction of things is not caused by some secondary agent introducing forms into matter). 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. 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." But what about in the beginning? Where did the forms of the first animals come from? Aquinas answers that "the primary establishment of these forms... must of necessity proceed from the Creator alone":

[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.

Objection: 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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AND NOW, THE ONE YOU'VE ALL BEEN WAITING FOR...

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

LONG Version of "Smoking Gun" Number 10

"SMOKING GUN" Number 10:

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.

Where Aquinas says this:

How did Aquinas define "perfect animals"?

Following Aristotle, Aquinas believed that there were various grades of perfection amongst animals. Those 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").

Defined in this narrow sense, "perfect animals" are roughly synonymous with the class of mammals - especially land-dwelling, carnivorous ones - but excluding rats and mice (which were believed to be generated spontaneously, in Aquinas' day). Birds and most reptiles lay eggs, so they are not "perfect animals" in the narrow sense.

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 describes the complexity of "perfect animals" here: Commentary on Aristotle's De Sensu et Sensato, Prologue, Commentary on 436a8 ("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");

Summa Contra Gentiles Book II chapter 72, paragraph 5 (perfect animals have "the greatest diversity of organs," because they perform "many operations" when exercising their "powers" - especially their sensory powers such as sight and hearing);

De Coelo, Book II Lecture 2, paragraph 301 (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");

De Coelo, Book II Lecture 13, paragraph 411 ("For animals of this sort, the more perfect they are, the greater variety do they exhibit in their parts");

Summa Theologica I, question 71 (perfect animals "have more distinct limbs, and generation of a higher order");

Summa Theologica I, q. 72 art. 1, Reply to Objection 1 ("their limbs are more distinct and their generation of a higher order"); and

Summa Contra Gentiles Book III, chapter 22, paragraph 7 (animals "that are more perfect and more powerful [get their nourishment] from those that are more imperfect and weaker").

Here are three longer quotes, showing that Aquinas regarded perfect animals as more complex than other animals, in terms of their bodily organs and their anatomy:

Summa Contra Gentiles Book II chapter 72, paragraph 5 (That The Soul Is In The Whole Body and Each Of Its 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.

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.... [A]mongst animals, those that live on land are, generally speaking, more perfect than birds and fishes, ... because their limbs are more distinct and their generation of a higher order...

Summa Theologica I, question 71 (The Work of the Fifth Day):

[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' Intelligent Design-style argument

In an age when almost everyone believed that simple animals were spontaneously generated from dead or decaying matter, the philosopher Avicenna (980-1037) had proposed that all animals - even the higher ones - could be generated in this way. In his Summa Theologica I, question 71, reply to objection 1, Aquinas alludes to Avicenna's views: "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." However, Aquinas disagreed with Avicenna; he thought it was impossible for inanimate forces to generate "perfect animals," as he called them. We've examined one reason why, in Smoking Gun number 8: according to Aquinas, "perfect animals," defined broadly as animals that reproduce sexually and breed true to type, can only be naturally generated from "seed" (the formative agent) acting on suitable matter, and both of these have to be supplied by their parents.

But Aquinas also formulated a second argument against Avicenna, based on the complexity of perfect animals, as defined in the narrow sense described above. This argument can be found in his Summa Theologica I, q. 91 art. 2, Reply to Objection 2. Because their bodies are more perfect, more conditions are required to produce them. In Intelligent Design terminology, perfect animals exhibit a high degree of specified complexity. 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. Readers will be able to see where Aquinas is heading here: only God, he writes, could have acted in the specific way required to produce these complex animals in the beginning. This accords well with Aquinas' statement in his Summa Contra Gentiles Book II chapter 43, paragraph 6 (That the distinction of things is not caused by some secondary agent introducing forms into matter), which I cited in "Smoking Gun" number 9: the original production of these animals' forms "must of necessity proceed from the Creator alone."

Here is Aquinas' explanation of why inanimate forces - even heavenly bodies, which were then believed to play a vital role in animal reproduction - are incapable of generating these "perfect" animals:

Summa Theologica I, q. 91 art. 2, Reply to Objection 2 (Whether the human body was immediately produced by God). Here's a brief excerpt:

Reply to Objection 2. Perfect animals, produced from seed, cannot be made by the sole power of a heavenly body, as Avicenna imagined... 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.

As we saw above, the reason why more conditions are required to produce perfect animals is 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.

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. The only way in which their forms can be naturally generated is from the father's "seed," according to Aquinas. (We now know that both parents contribute genetic information that helps build the form of the embryo, but that doesn't alter Aquinas' key point.) From this it follows that the first "perfect animals" must have been produced by God alone.

In his Summa Contra Gentiles Book II chapter 43, paragraph 6 (That the distinction of things is not caused by some secondary agent introducing forms into matter), Aquinas draws precisely this conclusion. Here's a brief excerpt:

...[A]ll motion toward form is brought about through the mediation of the heavenly motion... 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, as Avicenna thought - 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:

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 language used here - "there must exist" - suggests an unwillingness on Professor Tkacz's part to even consider the possibility that some organisms may have been produced immediately by a supernatural act of 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

LONG 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.... 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.... 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.

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:

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 Gun" number 9 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:

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.

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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, 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

LONG 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..

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:

[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 theere is an actual set of programs running within each cell in the body of a living organism (as Intelligent Design proponent Dr. Don Johnson contends), 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 found in DNA is an intelligent agent, is not an argument that Aquinas would have likely employed in its current form, because it employs abductive logic, or inference to the best explanation. 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. Also, the "standard" ID argument is often couched in probabilistic terms, but the mathematical notation for representing probabilities had not yet been invented in the thirteenth century, so such an argument would have seemed foreign to Aquinas.

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 produced 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, as a finite creature cannot produce an infinite effect.

(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 DNA, 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).

"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

LONG 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 Quaestiones Disputatae de Potentia Dei (Disputed Questions Concerning the Power of God), Q. IV article II, reply to objection 22 (Was matter formed all at once or by degrees?) Here's a brief excerpt:

Reply to the Twenty-Second Objection. ... 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. 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 ... 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.

Finally, 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.

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:

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

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 appeared to hedge his bets: "Observed species of plants and animals may or may not be descendent from common primordial ancestors."

In his article for the journal This Rock, Professor Tkacz also 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.

That sounds pretty Darwinian to me, when taken together with Professor Tkacz's previous comment.

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.

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
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LONG 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.

According to Aquinas, every feature of living things exists for a purpose.

Aquinas repeatedly insists that "God creates nothing in vain," that "nothing is void in God's works," and that "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:

"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 even if there is a theoretical possibility that it might have served no purpose. Hence 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, Aquinas asks whether in the state of innocence in Paradise, there would have been generation by coition (sexual intercourse). Aquinas writes that "nothing is void in God's works," so sexual intercourse would still have occurred, even if Adam and Eve 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. ... 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.

Aquinas' logic is clear: the philosophical axiom that "nothing is void in God's works" would be violated if there were even a theoretical possibility that genital organs might have served no purpose (e.g. if Adam and Eve had not fallen). Thus there must have been sexual intercourse, even in Paradise.

(b) Summa Theologica I, q. 67, art. 4, reply to obj. 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."

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 disagreed: 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 for the ostrich's wings, because of his theological belief that God makes nothing in vain.

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 expounds 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. ... 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.
... 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.

In his Summa Contra Gentiles, Book II, chapter 55, paragraph 13 (That intellectual substances are incorruptible), Aquinas writes:

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

Aquinas says the same thing in his Summa Contra Gentiles, Book III, chapter 48, paragraph 11 (That man's ultimate felicity does not come in this life):

[11] Again, it is impossible for natural desire to be unfulfilled, since "nature does nothing in vain." Now, natural desire would be in vain if it could never be fulfilled. Therefore, man's natural desire is capable of fulfillment, but not in this life, as we have shown. So, it must be fulfilled after this life. Therefore, man's ultimate felicity comes after this life.

(3) Directed at an unachievable goal

Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 13, paragraph 113:

113. ... 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.

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, as things in nature cannot 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) That which nothing aims for, tends towards, or strives to reach

Commentary on Aristotle's De Coelo et Mundo, Book I, Lecture 18, paragraph 183:

183. ...For neither God nor nature has made any place in vain, i.e., a place in which no body is apt to be.

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.

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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.

FINALLY, THE MOST DAMNING "SMOKING GUN" OF THEM ALL, FOR DARWIN-FRIENDLY "THOMISTS"...

"SMOKING GUN" Number 1 Number 2 Number 3 Number 4 Number 5 Number 6 Number 7
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LONG 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 his Summa Theologica I, q. 103 art. 5 (Whether all things are subject to the Divine government?), Aquinas addresses the question of whether all things are subject to the Divine government. First, he enumerates some common objections to the view that everything is subject to God's government. After that, he approvingly cites the words of St. Augustine of Hippo, who asserted 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 concurs with St. Augustine's opinion. Here's a brief excerpt from Aquinas' response:

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 that is not ordered to the Divine goodness as its end, as is clear from what we have said above (44, 4; 65, 2), so it is impossible for anything to escape from the Divine 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.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:

[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.

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