Faith and Reason: Both Come from God

Both the truths of faith and truths of reason come ultimately from God, who is the truth. The Catechism, citing the first and second Vatican Councils, puts the point as follows:

“Though faith is above reason, there can never be any real discrepancy between faith and reason. Since the same God who reveals mysteries and infuses faith has bestowed the light of reason on the human mind, God cannot deny himself, nor can truth ever contradict truth.”

“Consequently, methodical research in all branches of knowledge, provided it is carried out in a truly scientific manner and does not override moral laws, can never conflict with the faith, because the things of the world and the things of faith derive from the same God. The humble and persevering investigator of the secrets of nature is being led, as it were, by the hand of God in spite of himself, for it is God, the conserver of all things, who made them what they are” (159).

God as the Author of Two Books

Faith and reason are compatible because both faith and reason ultimately come from God. God is the author of two books—the book of creation and the book of revelation. Whatever is in creation, including chemistry, physics, biology, and sociology, arises ultimately from God, who is the First Cause. Whatever is in revelation—the identity of Jesus as true God and true man, the sacraments, and the nature of God as Father, Son, and Holy Spirit—arises from God. God does not contradict himself, so what we can learn from creation does not contradict what we learn from revelation.

Why Can't God Contradict Himself?

But why couldn’t God contradict himself? God cannot contradict himself for the same reason God cannot commit suicide. God cannot commit suicide because he is eternal, having perfect possession of life without beginning and without end. God is not composed of body and soul, such that he could begin to decompose. That God cannot kill himself is part of divine perfection. Likewise, that God cannot contradict himself is part of divine perfection. God’s knowledge is perfect, unerring, and utterly complete. Moreover, God is not composed of a mind having different parts that could be in contradiction. So God cannot be intellectually mistaken and self-contradictory. If God cannot contradict himself, then what God provides in revelation cannot contradict what God provides in creation.

Apparent Conflicts Between Faith and Reason

Of course, there can be apparent contradictions between faith and reason. For example, maybe a theologian misinterprets Scripture, and on the basis of this misinterpretation it seems that science and faith are in conflict. A famous example of this is when some theologians misunderstood Scripture as asserting that the faithful must believe that the earth rather than the sun was at the center of our solar system.

We know very well that the earth revolves around the sun, and we are not denying this if we say, “The sun is setting tonight at 7:35 p.m.” It would be both obnoxious and beside the point for someone to reply, “No, you should say, ‘The earth is rotating, making it the case that at 7:35 from our location the sun will no longer be visible.’” Hundreds of years ago, some theologians mistakenly took colloquial manners of speech about the sun for statements of scientific precision.

So, one way an apparent but illusory conflict between faith and reason can arise is through a misunderstanding of faith. Another way is through a misunderstanding of what is rational.

The Problem with David Hume’s Philosophy

For example, in his book An Inquiry Concerning Human Understanding, the philosopher David Hume said,

All the objects of human reason or enquiry may naturally be divided into two kinds, to wit, relations of ideas and matters of fact. Of the first kind are the sciences of geometry, algebra, and arithmetic, [which are]discoverable by the mere operation of thought. . . . Matters of fact, which are the second object of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing.

From this perspective, statements are meaningful only in two cases. Either the statement must be true by definition—“The whole is greater than its parts”—or the statement must be empirically verified: “This box of chocolate weighs six ounces.” Hume’s principle is that we should only accept what is true by definition (relation of ideas, like mathematics) or true by empirical verification (matters of fact, like experimental science). You’ll note that the statement “God exists” does not fit into either category. God is not a material object, composed of parts, so God cannot be empirically verified like a box of chocolates. Nor is it true by definition that “God exists” simply by virtue of the meaning of the word “God.” According to Hume, then, belief in God is “nothing but sophistry and illusion.”

If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.

However, it turns out that Hume’s principle is self-contradictory, since it is not true by definition (relation of ideas) or by empirical verification (matters of fact). Is Hume’s principle simply a matter of abstract reasoning concerning quantity or number? No. It is not true by definition of words, nor is it true like a mathematic formula. Does Hume’s principle contain any experimental reasoning concerning matters of fact and existence? No. It was not shown to be the case through dissecting frogs, mixing chemicals, or using Bunsen burners. So if we take Hume’s advice, we should commit Hume’s principle to the flames, for it can contain nothing but sophistry and illusion.

As Peter Kreeft pointed out, “If all statements that are neither mathematical nor empirical are meaningless, then that very statement (that all statements that are neither mathematical nor empirical are meaningless) is meaningless, because it is neither mathematical nor empirical.”

Faith and reason certainly can come into apparent contradiction if either someone misunderstands faith or someone misunderstands reason, or both. But faith and reason, properly understood, are harmonious.