Truth is the end of the universe.

—St. Thomas Aquinas, Summa Contra Gentiles, I.1

Truth envelops heaven and earth, and covers the natural and the supernatural on the roads of reason and faith. But not everyone sees a unity between reason and faith. Few actually wage war against religion. Many just find belief uncomfortable, and would prefer not to see creeds and confessions of faith spill into the realm of rational inquiry. Others keep faith apart from daily life, keeping difficult religious questions segregated from other aspects of their lives. The question remains—why do we need faith beyond natural knowing?

Four facts about the relationship between faith and reason can help us answer that question:

First, faith and reason are distinct. We all desire to know, but in several modes or ways—in one way by natural reason, in another by faith. Reason is proper to our nature, to who we are. It aids us in discovering the world and joins our mind to that world in a cognitional unity we call “truth.” To say we know the truth, after all, is to say that our minds conform with external realities. Faith also regards truth, but it does not do so simply by natural reflection. Faith is a cognitional assent to what is not immediately apparent. It is supernatural when directed to God.

Second, faith and reason do not compete. The wise man is the one who orders, and there is a perceived order among the truths of faith and reason. Both faith and reason seek what is true, but neither encroaches on the other’s method of knowing. Some truths about God exceed the ability of our natural reason—like the fact that God is triune, and that the Incarnation is possible. But there are other truths about God and the world that natural reason is able to reach—the laws of physics, for example, or even the fact that all matter finds its source in a single, creative cause. Truth is not contrary to truth, so neither is a point of reason opposed to an article of faith. If something is known to be true by faith, then reason cannot conclude its contrary. Likewise, if reason provides certainty on a given issue, then an opposed faith-claim would be a false belief.

Third, salvation is real. Both reason and faith have the same source in God, who is Divine Wisdom, the author of our existence as well as our salvation. Our salvation is supernatural, and so it requires a supernatural act on God’s part to bring us to eternal life. This divine act is called grace, and it gives us what we need to believe in God and in every truth given to us about him. God gives us faith through grace so that we may believe in what pertains to our salvation.

Fourth, revelation is both possible and necessary. We can’t perfectly move from natural causes and natural reason to all that pertains to God in his infinite being. This does not mean that reason is weak, but that it has a particular scope that can only know so much without faith. Mysteries hidden in God are proposed to us for belief in revelation, which, had they not been revealed, could not have been known simply by natural knowledge. Therefore, faith that regards the truths of revelation complements and extends reason; it does not limit or lessen its power.

Truth, then, is found in a twofold wisdom. To reason clearly is to see clearly, and to see what is beyond reason’s realm requires faith. Faith perfects us naturally and supernaturally. It gives us a complete perspective of the world, and shows an inner harmony within our body of beliefs along with what we know by reason. As the means by which we assent to what is divine, faith leads us to our perfection in attaining supreme wisdom. By reason and faith, therefore, let us pursue Wisdom itself:

Blessed is the man who meditates on wisdom and who reasons intelligently.
He who reflects in his mind on her ways will also ponder her secrets.
Pursue wisdom like a hunter, and lie in wait on her paths…
[You] will be sheltered by her from the heat, and will dwell in the midst of her glory.
—Sirach 14:20-22, 27

Image: Childe Hassam, Sunset at Sea