The City of God · Chapter
Of the divine Trinity, and the indications of its presence scattered everywhere among its works explained
Augustine expounds the doctrine of the Trinity—Father, Son, and Holy Spirit—as one God in three persons, co-eternal and consubstantial.
What happens
Augustine expounds the doctrine of the Trinity—Father, Son, and Holy Spirit—as one God in three persons, co-eternal and consubstantial. He suggests that the Holy Spirit may be understood as the substantial goodness and holiness common to Father and Son. He then interprets the creation narrative ("Let there be," made through the Word, and "God saw that it was good") as an enigma hinting at the Trinity, with the Holy Spirit as the goodness by which creation was made. This leads to a reflection on the holy city of angels, whose origin, wisdom, and blessedness derive from the Trinity.
Themes in this chapter
True Worship and the One God
Augustine affirms the indivisible unity of the triune God, contrasting with polytheistic worship.
Peace, Justice, and the Order of Love
The holy city's blessedness consists in subsisting in God, contemplating His truth, and loving His goodness—an ordered peace.
Characters to notice
- Augustine
Author and expositor of the Trinity, interpreting the creation account as revealing the three persons.
- Holy Scripture
Cited for the phrases 'Let there be' and 'God saw that it was good,' used to illustrate the Trinity.
Key passages
“We believe, we maintain, we faithfully preach, that the Father begat the Word, that is, Wisdom, by which all things were made, the only-begotten Son, one as the Father is one, eternal as the Father is eternal, and, equally with the Father, supremely good; and that the Holy Spirit is the Spirit alike of Father and of Son, and is Himself consubstantial and co-eternal with both; and that this whole is a Trinity by reason of the individuality of the persons, and one God by reason of the indivisible divine substance.”
Augustine declares the orthodox Christian doctrine of the Trinity: the Father begets the Son (the Word/Wisdom), who is co-eternal and consubstantial with the Father; the Holy Spirit proceeds from both and is equally consubstantial and co-eternal. The three persons are distinct, yet they are one God because of their indivisible substance.
This is a concise summary of Nicene Trinitarian theology as Augustine presents it.
“For it is the Father of the Word who said, Let there be. And that which was made when He spoke was certainly made by means of the Word. And by the words, 'God saw that it was good,' it is sufficiently intimated that God made what was made not from any necessity, nor for the sake of supplying any want, but solely from His own goodness, i.e., because it was good.”
Augustine interprets the Genesis creation account as revealing the Trinity: the Father speaks ('Let there be'), the Son is the Word through whom creation is made, and the Holy Spirit is the goodness by which God sees creation as good. Creation arises from God's free goodness, not from need.
This allegorical reading of Genesis is central to Augustine's argument for the Trinity's presence in creation.