CHAPTER VIII—Of the Relation of Human Reason to the first Truth of Faith¹⁶¹⁶The “first truth of faith” is God, not only that He is (His existence), but also what He is (His essential nature).

THE things of sense, from whence human reason takes its beginning of knowledge, retain in themselves some trace of imitation of God, inasmuch as they are, and are good; yet so imperfect is this trace that it proves wholly insufficient to declare the substance of God Himself. Since every agent acts to the producing of its own likeness, effects in their several ways bear some likeness to their causes: nevertheless the effect does not always attain to the perfect likeness of the agent that produces it. In regard then to 8knowledge of the truth of faith, which can only be thoroughly known to those who behold the substance of God, human reason stands so conditioned as to be able to argue some true likenesses to it: which likenesses however are not sufficient for any sort of demonstrative or intuitive comprehension of the aforesaid truth. Still it is useful for the human mind to exercise itself in such reasonings, however feeble, provided there be no presumptuous hope of perfect comprehension or demonstration. With this view the authority of Hilary agrees, who says (De Trinitate, ii, 10), speaking of such truth: “In this belief start, run, persist; and though I know that you will not reach the goal, still I shall congratulate you as I see you making progress. But intrude not into that sanctuary, and plunge not into the mystery of infinite truth; entertain no presumptuous hope of comprehending the height of intelligence, but understand that it is incomprehensible.”