On the Trinity
Augustine of Hippo (354–430)
First published 428
Augustine's De Trinitate, staged here in the public-domain NPNF English translation by Arthur West Haddan, revised by W. G. T. Shedd.
Book 1
Caput I: This Work is Written Against Those Who Sophistically Assail the Faith of the Trinity, Through Misuse of Reason. They Who Dispute Concerning God Err from a Threefold Cause. Holy Scripture, Removing What is False, Leads Us on by Degrees to Things Divine. What True Immortality is. We are Nourished by Faith, that We May Be Enabled to Apprehend Things Divine.
Caput II: In What Manner This Work Proposes to Discourse Concerning the Trinity.
Caput III: What Augustin Requests from His Readers. The Errors of Readers Dull of Comprehension Not to Be Ascribed to the Author.
Caput IV: What the Doctrine of the Catholic Faith is Concerning the Trinity.
Caput V: Of Difficulties Concerning the Trinity: in What Manner Three are One God, and How, Working Indivisibly, They Yet Perform Some Things Severally.
Caput VI: That the Son is Very God, of the Same Substance with the Father. Not Only the Father, But the Trinity, is Affirmed to Be Immortal. All Things are Not from the Father Alone, But Also from the Son. That the Holy Spirit is Very God, Equal with the Father and the Son.
Caput VII: In What Manner the Son is Less Than the Father, and Than Himself.
Caput VIII: The Texts of Scripture Explained Respecting the Subjection of the Son to the Father, Which Have Been Misunderstood. Christ Will Not So Give Up the Kingdom to the Father, as to Take It Away from Himself. The Beholding Him is the Promised End of All Actions. The Holy Spirit is Sufficient to Our Blessedness Equally with the Father.
Caput IX: All are Sometimes Understood in One Person.
Caput X: In What Manner Christ Shall Deliver Up the Kingdom to God, Even the Father. The Kingdom Having Been Delivered to God, Even the Father, Christ Will Not Then Make Intercession for Us.
Caput XI: By What Rule in the Scriptures It is Understood that the Son is Now Equal and Now Less.
Caput XII: In What Manner the Son is Said Not to Know the Day and the Hour Which the Father Knows. Some Things Said of Christ According to the Form of God, Other Things According to the Form of a Servant. In What Way It is of Christ to Give the Kingdom, in What Not of Christ. Christ Will Both Judge and Not Judge.
Caput XIII: Diverse Things are Spoken Concerning the Same Christ, on Account of the Diverse Natures of the One Hypostasis [Theanthropic Person]. Why It is Said that the Father Will Not Judge, But Has Given Judgment to the Son.
Book 2
Caput I: Preface
Caput I: There is a Double Rule for Understanding the Scriptural Modes of Speech Concerning the Son of God. These Modes of Speech are of a Threefold Kind.
Caput II: That Some Ways of Speaking Concerning the Son are to Be Understood According to Either Rule.
Caput III: Some Things Concerning the Holy Spirit are to Be Understood According to the One Rule Only.
Caput IV: The Glorification of the Son by the Father Does Not Prove Inequality.
Caput V: The Son and Holy Spirit are Not Therefore Less Because Sent. The Son is Sent Also by Himself. Of the Sending of the Holy Spirit.
Caput VI: The Creature is Not So Taken by the Holy Spirit as Flesh is by the Word.
Caput VII: A Doubt Raised About Divine Appearances.
Caput VIII: The Entire Trinity Invisible.
Caput IX: Against Those Who Believed the Father Only to Be Immortal and Invisible. The Truth to Be Sought by Peaceful Study.
Caput X: Whether God the Trinity Indiscriminately Appeared to the Fathers, or Any One Person of the Trinity. The Appearing of God to Adam. Of the Same Appearance. The Vision to Abraham.
Caput XI: Of the Same Appearance.
Caput XII: The Appearance to Lot is Examined.
Caput XIII: The Appearance in the Bush.
Caput XIV: Of the Appearance in the Pillar of Cloud and of Fire.
Caput XV: Of the Appearance on Sinai. Whether the Trinity Spake in that Appearance or Some One Person Specially.
Caput XVI: In What Manner Moses Saw God.
Caput XVII: How the Back Parts of God Were Seen. The Faith of the Resurrection of Christ. The Catholic Church Only is the Place from Whence the Back Parts of God are Seen. The Back Parts of God Were Seen by the Israelites. It is a Rash Opinion to Think that God the Father Only Was Never Seen by the Fathers.
Caput XVIII: The Vision of Daniel.
Book 3
Caput I: Preface
Caput I: What is to Be Said Thereupon.
Caput II: The Will of God is the Higher Cause of All Corporeal Change. This is Shown by an Example.
Caput III: Of the Same Argument.
Let us take, then, the case of a wise man, such that his rational soul is already partaker of the unchangeable and eternal truth, so that he consults it about all his actions, nor does anything at all, which he does not by it know ought to be done, in order that by being subject to it and obeying it he may do rightly. Suppose now that this man, upon counsel with the highest reason of the divine righteousness, which he hears with the ear of his heart in secret, and by its bidding, should weary his body by toil in some office of mercy, and should contract an illness; and upon consulting the physicians, were to be told by one that the cause of the disease was overmuch dryness of the body, but by another that it was overmuch moisture; one of the two no doubt would allege the true cause and the other would err, but both would pronounce concerning proximate causes only, that is, corporeal ones. But if the cause of that dryness were to be inquired into, and found to be the self-imposed toil, then we should have come to a yet higher cause, which proceeds from the soul so as to affect the body which the soul governs. Yet neither would this be the first cause, for that doubtless was a higher cause still, and lay in the unchangeable wisdom itself, by serving which in love, and by obeying its ineffable commands, the soul of the wise man had undertaken that self-imposed toil; and so nothing else but the will of God would be found most truly to be the first cause of that illness. But suppose now in that office of pious toil this wise man had employed the help of others to co-operate in the good work, who did not serve God with the same will as himself, but either desired to attain the reward of their own carnal desires, or shunned merely carnal unpleasantnesses;—suppose, too, he had employed beasts of burden, if the completion of the work required such a provision, which beasts of burden would be certainly irrational animals, and would not therefore move their limbs under their burdens because they at all thought of that good work, but from the natural appetite of their own liking, and for the avoiding of annoyance;—suppose, lastly, he had employed bodily things themselves that lack all sense, but were necessary for that work, as e.g. corn, and wine, and oils, clothes, or money, or a book, or anything of the kind;—certainly, in all these bodily things thus employed in this work, whether animate or inanimate, whatever took place of movement, of wear and tear, of reparation, of destruction, of renewal or of change in one way or another, as places and times affected them; pray, could there be, I say, any other cause of all these visible and changeable facts, except the invisible and unchangeable will of God, using all these, both bad and irrational souls, and lastly bodies, whether such as were inspired and animated by those souls, or such as lacked all sense, by means of that upright soul as the seat of His wisdom, since primarily that good and holy soul itself employed them, which His wisdom had subjected to itself in a pious and religious obedience?