The following quotations are roughly chronological.

On Repentance

Repentance, men understand, so far as nature is able, to be an emotion of the mind arising from disgust at some previously cherished worse sentiment: that kind of men I mean which even we ourselves were in days gone by— blind, without the Lord's light. From the reason of repentance, however, they are just as far as they are from the Author of reason Himself. Reason, in fact, is a thing of God, inasmuch as there is nothing which God the Maker of all has not provided, disposed, ordained by reason— nothing which He has not willed should be handled and understood by reason.(I).

On Prayer

The Spirit of God, and the Word of God, and the Reason of God— Word of Reason, and Reason and Spirit of Word— Jesus Christ our Lord, namely, who is both the one and the other, — has determined for us, the disciples of the New Testament, a new form of prayer.... our Lord Jesus Christ has been approved as the Spirit of God, and the Word of God, and the Reason of God: the Spirit, by which He was mighty; the Word, by which He taught; the Reason, by which He came. (I).

Of Patience

God suffers Himself to be conceived in a mother's womb, and awaits the time for birth; and, when born, bears the delay of growing up; and, when grown up, is not eager to be recognised, but is furthermore contumelious to Himself, and is baptized by His own servant. (III).

An Answer to the Jews

Well, then, Isaiah foretells that it behooves Him to be called Emmanuel; and that subsequently He is to take the power of Damascus and the spoils of Samaria, in opposition to the king of the Assyrians. “Now,” say they, “that (Christ) of yours, who has come, neither was called by that name, nor engaged in warfare.” But we, on the contrary, have thought they ought to be admonished to recall to mind the context of this passage as well. For subjoined is withal the interpretation of Emmanuel— “God with us” — in order that you may regard not the sound only of the name, but the sense too. For the Hebrew sound, which is Emmanuel, has an interpretation, which is, God with us. Inquire, then, whether this speech, “God with us” (which is Emmanuel), be commonly applied to Christ ever since Christ's light has dawned, and I think you will not deny it. For they who out of Judaism believe in Christ, ever since their believing on Him, do, whenever they shall wish to say Emmanuel, signify that God is with us: and thus it is agreed that He who was ever predicted as Emmanuel is already come, because that which Emmanuel signifies has come— that is, “God with us.” (IX).

Look at the universal nations thenceforth emerging from the vortex of human error to the Lord God the Creator and His Christ. (XII).

Prescription Against Heretics

Now, with regard to this rule of faith— that we may from this point acknowledge what it is which we defend— it is, you must know, that which prescribes the belief that there is one only God, and that He is none other than the Creator of the world, who produced all things out of nothing through His own Word, first of all sent forth; that this Word is called His Son, and, under the name of God, was seen “in diverse manners” by the patriarchs, heard at all times in the prophets, at last brought down by the Spirit and Power of the Father into the Virgin Mary, was made flesh in her womb, and, being born of her, went forth as Jesus Christ; thenceforth He preached the new law and the new promise of the kingdom of heaven, worked miracles; having been crucified, He rose again the third day; (then) having ascended into the heavens, He sat at the right hand of the Father; sent instead of Himself the Power of the Holy Ghost to lead such as believe; will come with glory to take the saints to the enjoyment of everlasting life and of the heavenly promises, and to condemn the wicked to everlasting fire, after the resurrection of both these classes shall have happened, together with the restoration of their flesh. (XIII).

Christ Jesus our Lord (may He bear with me a moment in thus expressing myself!), whosoever He is, of what God soever He is the Son, of what substance soever He is man and God, of what faith soever He is the teacher... (XX).

Apology

The object of our worship is the One God, He who by His commanding Word, His arranging Wisdom, His Mighty Power, brought forth out of nothing the entire substance of our world, with all its array of elements, bodies, spirits, for the glory of His majesty, whence also the Greeks have given it the name of kosmos. (17).

For from the first He sent messengers into the world, men whose spotless righteousness made them worthy to know the Most High, and to reveal Him... that they might proclaim there is one God only who made all things. (18).

Then, too, the common people have now some knowledge of Christ, and think of Him as but a man, one indeed such as the Jews condemned, so that some may naturally enough have taken up the idea that we are worshippers of a mere human being. But we are neither ashamed of Christ, for we rejoice to be counted His disciples, and in His name to suffer. Nor do we differ from the Jews concerning God. We must make, therefore, a remark or two as to Christ's divinity (necesse est igitur pauca de Christo ut deo)..... Accordingly, he appeared among us, whose coming to renew and illuminate man's nature was foreproclaimed by God, I mean Christ, the Son of God. And so the Supreme Head and Master of this grace and discipline, the Enlightener and Trainer of humanity, God's own Son, was announced among us.... But, first, I shall discuss his essential nature, and so the nature of his birth will be understood. We have already asserted that God made the world, and all which it contains, by His Word, and Reason, and Power. It is abundantly plain that your philosophers, too, regard the Logos, that is, the Word and Reason, as the Creator of the universe.... in like manner, hold that the Word, and Reason, and Power, by which we have said God made all, have spirit as their proper and essential substratum, in which the Word has inbeing to give forth utterances, and reason abides to dispose and arrange, and power is over all to execute. We have been taught that he proceeds forth from God, and in that procession he is generated, so that he is the Son of God, and is called deity from unity of substance with God (et deum dictum ex unitate substantiae). For God, too, is a Spirit. Even when the ray is shot from the sun, it is still part of the parent mass; the sun will still be in the ray, because it is a ray of the sun there is no division of substance, but merely an extension. Thus Christ is spirit of Spirit, and god/deity of God/deity (de spiritu spiritus et de deo deus), as light of light is kindled. The material matrix remains entire and unimpaired, though you derive from it any number of shoots possessed of its qualities; so, too, that which has come forth out of God is at once god/deity and the Son of God (Manet integra et indefecta materiae matrix, etsi plures inde traduces qualitatis mutueris: ita et quod de deo profectum est, deus et dei filius et unus ambo), and the two are one. In this way also, as he is spirit of Spirit and god/deity of God/Deity, he is made a second in manner of existence, in position, not in nature, and he did not withdraw from the original source, but went forth (Ita et de spiritu spiritus et de deo deus modulo alternum numerum, gradu non statu fecit, et a matrice non recessit sed excessit)... This ray of God, then, as it was always foretold in ancient times, descending into a certain virgin, and made flesh in her womb, is in his birth God and man united (et in utero eius caro figuratus nascitur homo deo mixtus). The flesh formed by the Spirit is nourished, grows up to manhood, speaks, teaches, works, and is the Christ.... he was the Logos of God, that primordial first-begotten Word, accompanied by power and reason, and based on Spirit, that He [God] who was now doing all things by His Word, and He who had done that of old, were one and the same.... Surely Christ, then, had a right to reveal deity, which was in fact His own essential possession. (21).

Who is this Christ with his fables? is he an ordinary man? is he a sorcerer? was his body stolen by his disciples from its tomb? is he now in the realms below? or is he not rather up in the heavens, thence about to come again, making the whole world shake, filling the earth with dread alarms, making all but Christians wail, as the Power of God, and the Spirit of God, as the Word, the Reason, the Wisdom, and the Son of God? (23).

Against Hermogenes

I maintain that the substance existed always with its own name, which is God; the title Lord was afterwards added, as the indication indeed of something accruing. For from the moment when those things began to exist, over which the power of a Lord was to act, God, by the accession of that power, both became Lord and received the name thereof. Because God is in like manner a Father, and He is also a Judge; but He has not always been Father and Judge, merely on the ground of His having always been God. For He could not have been the Father previous to the Son, nor a Judge previous to sin. There was, however, a time when neither sin existed with Him, nor the Son; the former of which was to constitute the Lord a Judge, and the latter a Father. In this way He was not Lord previous to those things of which He was to be the Lord. But He was only to become Lord at some future time: just as He became the Father by the Son, and a Judge by sin, so also did He become Lord by means of those things which He had made, in order that they might serve Him. (III).

For we shall be even gods, if we, shall deserve to be among those of whom He declared, "I have said, Ye are gods," and, "God standeth in the congregation of the gods." But this comes of His own grace, not from any property in us, because it is He alone who can make gods. (V).

But if this same Wisdom is the Word of God, in the capacity of Wisdom, and (as being He) without whom nothing was made, just as also (nothing) was set in order without Wisdom, how can it be that anything, except the Father, should be older, and on this account indeed nobler, than the Son of God, the only-begotten and first-begotten Word? (XVIII)

Against Marcion

So far as a human being can form a definition of God, I adduce one which the conscience of all men will also acknowledge, that God is the great Supreme existing in eternity, unbegotten, unmade without beginning, without end....Whatever other god, then, you may introduce, you will at least be unable to maintain his divinity under any other guise, than by ascribing to him too the property of Godhead--both eternity and supremacy over all. How, therefore, can two great Supremes co-exist, when this is the attribute of the Supreme Being, to have no equal, an attribute which belongs to One alone, and can by no means exist in two? (Against Marcion, I, 3).

These all start with the same principles of the faith, so far as relates to the One Only God the Creator and His Christ. (Against Marcion, IV, 2).

The Christ of the Creator had to be called a Nazarene according to prophecy. (Against Marcion, IV, 8).

The Son of the Creator, that he might drive them [demons] out, not indeed by his own power, but by the authority of the Creator... If, therefore, neither he [the Son of the Creator] had preached, nor they had known, any other God but the Creator, he was announcing the Kingdom of that God whom he knew to be the only God known to those who were listening to him. (Against Marcion, IV, 8).

Therefore Christ belonged to John, and John to Christ, while both belonged to the Creator. (Against Marcion, IV, 11).

For it was he who used to speak in the prophets, the Word, the Creator's Son. (Against Marcion, IV, 13).

The apostle can hardly be thought to have ranked the Creator among those who are called gods, without being so, since, even if they had been gods, "to us there is but one God, the Father." Now, from whom do all things come to us, but from Him to whom all things belong? And pray tell, what things are these? You have them in a preceding part of the letter, "All things are yours, whether Paul, or Apollos, or Cephas, or the world, or life, or death, or things present, or things to come." He makes the Creator, then the God of all things, from whom proceed both the world and life and death, which. cannot possibly belong to the other god. From Him, therefore, among those "all things" comes also Christ. (Against Marcion, Book V, 7).

Against Praxeas

Against Praxeas is the main document written by Tertullian which illustrates his beliefs concerning the relationship between the Father, Son, and Holy Spirit. Scholars strongly believe it was written after he became a Montanist.

We, however, as we indeed always have done and more especially since we have been better instructed by the Paraclete [the Comforter], who leads men indeed into all truth, believe that there is One God Alone, but under the following dispensation, or oikonomia, as it is called, that this One God Alone also has a Son, His Word, who proceeded from Himself, by whom all things were made, and without whom nothing was made. Him we believe to have been sent by the Father into the virgin, and to have been born of her, being both human and deity, the Son of Man and the Son of God (hunc missum a patre in virginem et ex ea natum hominem et deum filium hominis et filium dei), and to have been called by the name of Jesus Christ, we believe him to have suffered, died, and been buried, according to the Scriptures, and, after He had been raised again by the Father and taken back to heaven, to be sitting at the right hand of the Father, and that he will come to judge the living and the dead, who sent also from heaven from the Father, according to his own promise, the Holy Spirit, the Paraclete, the sanctifier of the faith of those who believe in the Father, and in the Son, and in the Holy Spirit. That this rule of faith has come down to us from the beginning of the gospel.... All are of One, by unity of substance, while the mystery of the dispensation (oikonomia sacramentum), is still kept, which distributes the unity into a trinity, placing in their order the three persons, the Father, the Son, and the Holy Spirit (quae unitatem in trinitatem disponit, tres dirigens patrem et filium et spiritum): three, however, not in condition, but in degree, not in substance, but in form, not in power, but in aspect, yet of one substance, and of one condition, and of one power, inasmuch as He is one God, from whom these degrees and forms and aspects are reckoned, under the name of the Father, and of the Son, and of the Holy Spirit (tres autem non statu sed gradu, nec substantia sed forma, nec potestate sed specie, unius autem substantiae et unius status et unius potestatis, quia unus deus ex quo et gradus isti et formae et species in nomine patris et filii et spiritus sancti deputantur). (Against Praxeas, 2).

Therefore, inasmuch as the Divine Monarchy (monarchia divina) also is administered by so many legions and hosts of angels, according as it is written, "You??? and thousands ministered to Him, and ten thousand times ten thousand stood before Him," and since it has not from this circumstance ceased to be the rule of one (so as no longer to be a monarchy), because it is administered by so many thousands of powers; how comes it to pass that God should be thought to suffer division and severance in the Son and in the Holy Ghost, who have the second and the third places assigned to them (in filio et in spiritu sancto secundum et tertium sortitis locum), and who are so closely joined with the Father in His substance (, when He suffers no such (division and severance) in the multitude of so many angels? Do you really suppose that those, who are naturally members of the Father's own substance (substantia patris), pledges of His love, instruments of His might, nay, His power itself and the entire system of His monarchy, are the overthrow and destruction thereof? You are not right in so thinking. (Against Praxeas, 3 ).

But as for me, who derive the Son from no other source but from the substance of the Father (de substantia patris), and as doing nothing without the Father's will, and as having received all power from the Father (omnem a patre consecutum potestatem), how can I be possibly destroying the Monarchy from the faith, when I preserve it in the Son just as it was committed to Him by the Father? The same remark with respect to the third degree, because I believe the Spirit [to proceed] from no other source than from the Father through the Son (hoc mihi et in tertium gradum dictum sit, quia spiritum non aliunde puto quam a patre per filium). (Against Praxeas, 4 ).

I am led to other arguments derived from God's own dispensation, in which He existed before the creation of the world, up to the generation of the Son. For before all things God was alone being in Himself and for Himself universe, and space, and all things (ante omnia enim deus erat solus, ipse sibi et mundus et locus et omnia). Moreover, He was alone, because there was nothing external to Him but Himself. Yet even not then was He alone; for He had with Him that which He possessed in Himself, that is to say, His own Reason (rationem). For God is rational (rationalis, and Reason (ratio) was first in Him; and so all things were from Himself. this Reason (ratio) is His own Thought/Consciousness) (sensus) which the Greeks call logos, by which term we also designate Word (sermonem) or Discourse and therefore it is now usual with our people, owing to the mere simple interpretation of the term, to say that the Word (sermonem) was in the beginning with God, although it would be more suitable to regard Reason (rationem) as the more ancient, because God had not Word (sermonalis) from the beginning, but He had Reason (rationalis) even before the beginning, because also Word (sermo) itself consists of Reason (ratione), which it thus proves to have been the prior existence as being its own substance (substantiam). Not that this distinction is of any practical moment. For although God had not yet sent out His Word (sermonem), He still had Him within Himself, both in company with and included within His very Reason (ratione), as He silently planned and arranged within Himself everything which He was afterwards about to utter through His Word (sermonem). Now, while He was thus planning and arranging with His own Reason (ratione, He was actually causing that to become Word ratione which He was dealing with in the way of Word (sermonem) or Discourse. And that you may the more readily understand this, consider first of all, from your own self, who are made "in the image and likeness of God" (imagine et similitudine dei), for what purpose it is that you also possess reason in yourself (rationem), who are a rational creature (animal rationale), as being not only made by a rational Artificer, but actually animated out of His substance (a rationali scilicet artifice non tantum factus sed etiam ex substantia ipsius animatus). Observe, then, that when you are silently conversing with yourself, this very process is carried on within you by your reason (ratione), which meets you with a word sermone) at every movement of your thought (cogitatus), at every impulse of your conception (sensus). Whatever you think (cogitaveris), there is a word (sermo); whatever you conceive (senseris, there is reason (ratio). You must needs speak it in your mind (loquaris illud in animo necesse est), and while you are speaking, you admit speech as an interlocutor with you, involved in which there is this very reason, whereby, while in thought you are holding converse with your word, you are producing thought by means of that converse with your word (et dum loqueris conlocutorem pateris sermonem, in quo inest haec ipsa ratio qua cum eo cogitans loquaris per quem loquens cogitas). Thus, in a certain sense, the word is a second person within you, through which in thinking you utter speech, and through which also, in uttering speech you generate thought (ita secundus quodammodo in te est sermo per quem loqueris cogitando et per quem cogitas loquendo). The word (sermo) is itself a different thing from yourself. Now how much more fully is all this transacted in God, whose image and likeness (imago et similitudo) even you are regarded as being, inasmuch as He has reason ratione within Himself even while He is silent, and involved in that Reason (ratione) His Word (sermonem). I may therefore without rashness first lay this down (as a fixed principle) that even then before the creation of the universe God was not alone, since He had within Himself both Reason(rationem), and, inherent in Reason (ratione), His Word (sermonem), which He made second to Himself by arousing it within Himself. (Against Praxeas, 5).

For before all things God was Alone, being in Himself and for Himself universe, and space, and all things. Moreover, He was Alone, because there was nothing external to Him but Himself. Yet even not then was He Alone, for He had with Him that which He possessed in Himself, that is to say, His own Reason. For God is rational, and Reason was first in Him, and so all things were from Himself. This Reason is His own Thought (or Consciousness) which the Greeks call Logos, by which term we also designate Word...that even then before the creation of the universe God was not alone, since He had within Himself both Reason, and, inherent in Reason, His Word, which He made second to Himself by arousing it within Himself. (Against Praxeas, 5).

Thus does He make him equal to Him. For by proceeding from Himself, he became His first-begotten Son, because begotten before all things, and His only-begotten also, because alone begotten of God, in a way peculiar to Himself, from the womb of His own heart.... He became also the Son of God, and was begotten when he proceeded forth from Him.... whatever, therefore, was the substance of the Word that I designate a person, I claim for it the name of Son, and while I recognize the Son, I assert his distinction as second to the Father. (Against Praxeas, 7).

For the Father is the entire substance, but the Son is a derivation and portion of the whole, as he himself confesses, "My Father is greater than I." In the Psalm his inferiority is described as being "a little lower than the angels." Thus the Father is distinct from the Son, being greater than the Son, inasmuch as He who begets is one, and he who is begotten is another. He, too, who sends is one, and he who is sent is another, and He, again, who makes is one, and he through whom the thing is made is another. (Against Praxeas, 9).

when all the Scriptures attest the clear existence of, and distinction in trinity (quando scripturae omnes et demonstrationem et distinctionem trinitatis, and indeed furnish us with our Rule of faith, that He who speaks; and He of whom He speaks, and to whom He speaks, cannot possibly seem to be One and the same... the distinction in the trinity is clearly set forth (his itaque paucis tamen manifeste distinctio trinitatis exponitur). For there is the Spirit Himself who speaks, and the Father to whom He speaks, and the Son of whom He speaks. In the same manner, the other passages also establish each one of several Persons in His special character, addressed as they in some cases are to the Father or to the Son respecting the Son, in other cases to the Son or to the Father concerning the Father, and again in other instances to the (Holy) Spirit. (XI).

If the number of the Trinity also offends you, as if it were not connected in the simple Unity, I ask you how it is possible for a Being who is merely and absolutely One and Singular, to speak in plural phrase, saying, "Let us make man in our own image, and after our own likeness;" whereas He ought to have said, "Let me make man in my own image, and after my own likeness," as being a unique and singular Being? In the following passage, however, "Behold the man is become as one of us," He is either deceiving or amusing us in speaking plurally, if He is One only and singular. Or was it to the angels that He spoke, as the Jews interpret the passage, because these also acknowledge not the Son? Or was it because He was at once the Father, the Son, and the Spirit, that He spoke to Himself in plural terms, making Himself plural on that very account? Nay, it was because He had already His Son close at His side, as a second Person, His own Word, and a third Person also, the Spirit in the Word, that He purposely adopted the plural phrase, "Let us make;" and, "in our image;" and, "become as one of us." (XII).

Last Update: January 23, 2011

Notes:

Documents to still investigate:

Finish and Review Praxeas

On the Flesh of Christ

On the Resurrection of Flesh