Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 13

Chapter 13.—That When It is Expounded What Saturn Is, What Genius Is, It Comes to This, that Both of Them are Shown to Be Jupiter.

But why speak more of this Jupiter, with whom perchance all the rest are to be identified; so that, he being all, the opinion as to the existence of many gods may remain as a mere opinion, empty of all truth?  And they are all to be referred to him, if his various parts and powers are thought of as so many gods, or if the principle of mind which they think to be diffused through all things has received the names of many gods from the various parts which the mass of this visible world combines in itself, and from the manifold administration of nature.  For what is Saturn also?  “One of the principal gods,” he says, “who has dominion over all sowings.”  Does not the exposition of the verses of Valerius Soranus teach that Jupiter is the world, and that he emits all seeds from himself, and receives them into himself?

It is he, then, with whom is the dominion of all sowings.  What is Genius?  “He is the god who is set over, and has the power of begetting, all things.”  Who else than the world do they believe to have this power, to which it has been said:

“Almighty Jove, progenitor and mother?”

And when in another place he says that Genius is the rational soul of every one, and therefore exists separately in each individual, but that the corresponding soul of the world is God, he just comes back to this same thing,—namely, that the soul of the world itself is to be held to be, as it were, the universal genius.  This, therefore, is what he calls Jupiter.  For if every genius is a god, and the soul of every man a genius, it follows that the soul of every man is a god.  But if very absurdity compels even these theologists themselves to shrink from this, it remains that they call that genius god by special and pre-eminent distinction, whom they call the soul of the world, and therefore Jupiter.