Chapter 8 — In what relation human reason stands to the truth of faith

It would also seem well to observe that sensible things, from which human reason derives the source of its knowledge, retain a certain trace of likeness to God, but so imperfect that it proves altogether inadequate to manifest the substance itself of God. For effects resemble their causes according to their own mode, since like action proceeds from like agent; and yet the effect does not always reach to a perfect likeness to the agent. Accordingly, human reason is adapted to the knowledge of the truth of faith (which can be known in the highest degree only by those who see the divine substance) insofar as it is able to put together certain probable arguments in support of it, which nevertheless are insufficient to enable us to understand the aforesaid truth as though it were demonstrated or understood in itself.

And yet, however weak these arguments may be, it is useful for the human mind to be practiced in them, so long as it does not pride itself on having comprehended or demonstrated, since although our view of the sublimest things is limited and weak, it is most pleasant to be able to catch but a glimpse of them, as appears from what has been said. (Ch. 5.)

The authority of Hilary concords with this, for he says in his book On the Trinity, (Hilary, On the Trinity, bk. 2, cc. 10–11.) while speaking of this same truth: begin by believing these things, advance and persevere, and though I know you will not arrive, I shall rejoice at your advance. For he who devoutly follows in pursuit of the infinite, though he never come up with it, will always advance by setting forth. Yet do not pry into that secret, and do not meddle in the mystery of the birth of the infinite, (The word interminabilis should actually be inopinabilis, i.e., of that which surpasses our ken.) nor presume to grasp that which is the summit of understanding, but understand that there are things you cannot grasp.