“We should not pretend to understand the world only by the intellect; we apprehend it just as much by feeling. Therefore, the judgment of the intellect is, at best, only the half of truth, and must, if it be honest, also come to an understanding of its inadequacy.”

Letter to Dorothy Day (20 December 1961).
Context: Persons are not known by intellect alone, not by principles alone, but only by love. It is when we love the other, the enemy, that we obtain from God the key to an understanding of who he is, and who we are. It is only this realization that can open to us the real nature of our duty, and of right action. To shut out the person and to refuse to consider him as a person, as an other self, we resort to the impersonal "law" and to abstract "nature." That is to say we block off the reality of the other, we cut the intercommunication of our nature and his nature, and we consider only our own nature with its rights, its claims, it demands. And we justify the evil we do to our brother because he is no longer a brother, he is merely an adversary, an accused. To restore communication, to see our oneness of nature with him, and to respect his personal rights and his integrity, his worthiness of love, we have to see ourselves as similarly accused along with him … and needing, with him, the ineffable gift of grace and mercy to be saved. Then, instead of pushing him down, trying to climb out by using his head as a stepping-stone for ourselves, we help ourselves to rise by helping him to rise. For when we extend our hand to the enemy who is sinking in the abyss, God reaches out to both of us, for it is He first of all who extends our hand to the enemy. It is He who "saves himself" in the enemy, who makes use of us to recover the lost groat which is His image in our enemy.