8 It is difficult to understand how you have been taken with the absurd idea of placing the power of the Son in the sun, and His wisdom in the moon. For, as the Son remains inseparably in the Father, His wisdom and power cannot be separated from one another, so that one should be in the sun and the other in the moon. Only material things can be thus assigned to separate places. If you only understood this, it would have prevented you from taking the productions of a diseased fancy as the material for so many fictions.
But there is inconsistency and improbability as well as falsehood in your ideas. For, according to you, the seat of wisdom is inferior in brightness to the seat of power. Now energy and productiveness are the qualities of power, whereas light teaches and manifests; so that if the sun had the greater heat, and the moon the greater light, these absurdities might appear to have some likelihood to men of carnal minds, who know nothing except through material conceptions. From the connection between great heat and motion, they might identify power with heat; while light from its brightness, and as making things discernible, they might represent wisdom.
But what folly as well as profanity, in placing power in the sun, which excels so much in light, and wisdom in the moon, which is so inferior in brightness! And while you separate Christ from Himself, you do not distinguish between Christ and the Holy Spirit; whereas Christ is one, the power of God, and the wisdom of God, and the Spirit is a distinct person. But according to you, the air, which you make the seat of the Spirit, fills and pervades the universe. So the sun and moon in their course are always united to the air.
But the moon approaches the sun at one time, and recedes from it at another. So that, if we may believe you, or rather, if we may allow ourselves to be imposed on by you, wisdom recedes from power by half the circumference of a circle, and again approaches it by the other half. And when wisdom is full, it is at a distance from power. For when the moon is full, the distance between the two bodies is so great, that the moon rises in the east while the sun is setting in the west.
But as the loss of power produces weakness, the fuller the moon is, the weaker must wisdom be. If, as is certainly true, the wisdom of God is unchangeable in power, and the power of God unchangeable in wisdom, how can you separate them so as to assign them to different places? And how can the place be different when the substance is the same? Is this not the infatuation of subjection to material fancies; showing such a want of power and wisdom that your wisdom is as weak as your power is foolish?
This execrable absurdity would divide Christ between the sun and the moon—His power in one, and His wisdom in the other; so that He would be incomplete in both, lacking wisdom in the sun, and power in the moon, while in both He supplies youths, male and female, to excite the affection of the princes and princesses of darkness. Such are the tenets which you learn and profess. Such is the faith which directs your conduct. And can you wonder that you are regarded with abhorrence?
Source: Reply to Faustus the Manichaean (New Advent)