St. Thomas can be quite difficult for a beginner to read, particularly those portions of his work that rely heavily on Aristotle. For this lesson I’m having you look at a couple selections from the Summa Contra Gentiles, on the relationship between faith and reason. It’s not the precise topic covered in the video, but they complement each other.
The text of the reading follows below the video.
THAT THE TRUTH OF REASON IS NOT OPPOSED TO THE TRUTH OF THE CHRISTIAN FAITH
Now, although the truth of the Christian faith which we have discussed surpasses the capacity of the reason, nevertheless that truth that the human reason is naturally endowed to know cannot be opposed to the truth of the Christian faith.
For that with which the human reason is naturally endowed is clearly most true; so much so, that it is impossible for us to think of such truths as false. Nor is it permissible to believe as false that which we hold by faith, since this is confirmed in a way that is so clearly divine. Since, therefore, only the false is opposed to the true, as is clearly evident from an examination of their definitions, it is impossible that the truth of faith should be opposed to those principles that the human reason knows naturally.
Furthermore, that which is introduced into the soul of the student by the teacher is contained in the knowledge of the teacher–unless his teaching is fictitious, which it is improper to say of God. Now, the knowledge of the principles that are known to us naturally has been implanted in us by God; for God is the Author of our nature. These principles, therefore, are also contained by the divine Wisdom. Hence, whatever is opposed to them is opposed to the divine Wisdom, and, therefore, cannot come from God. That which we hold by faith as divinely revealed, therefore, cannot be contrary to our natural knowledge.
Again. In the presence of contrary arguments our intellect is chained, so that it cannot proceed to the knowledge of the truth. If, therefore, contrary knowledges were implanted in us by God, our intellect would be hindered from knowing truth by this very fact. Now, such an effect cannot come from God.
And again. What is natural cannot change as long as nature does not. Now, it is impossible that contrary opinions should exist in the same knowing subject at the same time. No opinion or belief, therefore, is implanted in man by God which is contrary to man’s natural knowledge.
Therefore, the Apostle says: “The word is nigh thee, even in thy mouth and in thy heart. This is the word of faith, which we preach” (Rom. 10:8). But because it overcomes reason, there are some who think that it is opposed to it: which is impossible.
The authority of St. Augustine also agrees with this. He writes as follows: “That which truth will reveal cannot in any way be opposed to the sacred books of the Old and the New Testament” [De genesi ad litteram II, 18].
From this we evidently gather the following conclusion: whatever arguments are brought forward against the doctrines of faith are conclusions incorrectly derived from the first and self-evident principles embedded in nature. Such conclusions do not have the force of demonstration; they are arguments that are either probable or sophistical. And so, there exists the possibility to answer them.
HOW THE HUMAN REASON IS RELATED TO THE TRUTH OF FAITH
There is also a further consideration. Sensible things, from which the human reason takes the origin of its knowledge, retain within themselves some sort of trace of a likeness to God. This is so imperfect, however, that it is absolutely inadequate to manifest the substance of God. For effects bear within themselves, in their own way, the likeness of their causes, since an agent produces its like; yet an effect does not always reach to the full likeness of its cause. Now, the human reason is related to the knowledge of the truth of faith (a truth which can be most evident only to those who see the divine substance) in such a way that it can gather certain likenesses of it, which are yet not sufficient so that the truth of faith may be comprehended as being understood demonstratively or through itself.
Yet it is useful for the human reason to exercise itself in such arguments, however weak they may be, provided only that there be present no presumption to comprehend or to demonstrate. For to be able to see something of the loftiest realities, however thin and weak the sight may be, is, as our previous remarks indicate, a cause of the greatest joy.
The testimony of Hilary agrees with this. Speaking of this same truth, he writes as follows in his De Trinitate [II, 10, ii]: “Enter these truths by believing, press forward, persevere. And though I may know that you will not arrive at an end, yet I will congratulate you in your progress. For, though he who pursues the infinite with reverence will never finally reach the end, yet he will always progress by pressing onward. But do not intrude yourself into the divine secret, do not, presuming to comprehend the sum total of intelligence, plunge yourself into the mystery of the unending nativity; rather, understand that these things are incomprehensible.”