Aquinas

Thomas Aquinas, OP

In the thirteenth century the Christian West received a shock it was not prepared for. The complete works of Aristotle, lost to Europe for seven hundred years, came flooding back through translations out of the Arabic, and they were magnificent and they were dangerous. Here was a whole philosophy, built by pure reason, that explained the world entire, the stars, the soul, ethics, causation, with no need of revelation, no creation in time, no watching providence, no immortal individual soul. To many churchmen Aristotle looked like a solvent that would dissolve the faith, and they moved to ban him. Into that crisis walked a large, slow, silent Italian friar, nicknamed the Dumb Ox by classmates who mistook his quiet for stupidity, who would make the most audacious bet in the history of Christian thought: that Aristotle was not the enemy of faith but its greatest ally, and that reason and revelation, each followed honestly to the end, could not finally contradict each other, because they have the same author. Thomas Aquinas spent his life proving it, and the synthesis he built held up the Catholic mind for the next seven centuries.

Two paths to one truth. The bet rested on a single liberating conviction: that there is only one truth, reached by two roads. Some things, Aquinas held, reason can discover on its own, that the world has a first cause, that the soul is more than matter, the shape of the virtues. Other things, the Trinity, the Incarnation, the world's beginning in time, reason cannot prove and must receive from revelation. But the two never collide, because God is the author both of the world reason studies and of the revelation faith receives, and God does not lie or contradict himself. So the believer need not fear honest inquiry, and the philosopher need not fear faith; each is free to push as hard as it can, trusting that they are climbing the same mountain from different sides. Aquinas put it in a phrase that became the motto of an entire sensibility: grace does not destroy nature but perfects it. Faith does not cancel reason, or the body, or art, or the natural world; it completes them. It is one of the most confident positions any thinker has ever taken, a wager that reality is intelligible all the way down and friendly to the mind that dares to question it.

The fairest book ever written. That confidence shows in how Aquinas writes, and the form is as instructive as anything it carries. The Summa Theologiae, his masterwork, is built out of thousands of small units called articles, and every one follows the same remarkable shape. He poses a question, can God's existence be proved, is it ever right to take a life, does the soul outlast the body, and then, before a word of his own view, he sets out the strongest objections to the position he means to defend, frequently putting his opponents' case better than they put it themselves. Only then comes a countervailing authority, then his own measured response, and then, one by one, a patient reply to each objection in turn. Nothing is brushed aside; every serious position is met at full strength. It is, in its way, the fairest argumentative form ever devised, a whole philosophy conducted as a disciplined public debate in which the other side always speaks first and is never caricatured. To read the Summa is to watch a mind so sure that truth will win that it hands its opponents the sharpest possible weapons before it answers them. The form itself is worth stealing: state the best case against you before you make your own.

From the world, not the word. When Aquinas turns to the existence of God, he makes a move that quietly rebukes Anselm in the room next door. You cannot, he insists, prove God from the bare idea of God, because we have no direct insight into what God is; the ontological argument tries to read existence off a definition we do not actually possess. If God is to be shown at all, it must be from the world, reasoning backward from effects we can see to the cause they require. His Five Ways are five such paths, and they share a single logic: each begins from a plain feature of experience, that things move, that things are caused, that things come to be and pass away, that things vary in goodness, that things act toward ends, and argues that each would be unintelligible without a first term the chain cannot supply for itself. There must be something that moves without being moved, causes without being caused, exists without being able not to exist. These are not knock-down proofs, and Aquinas did not claim they deliver the full God of faith, only a bare "and this all call God." But the direction is the reverse of Anselm's: not down from thought to the world, but up from the world toward its source.

To be is an act. Beneath the proofs lies Aquinas's deepest and most original idea, the one that carries him past even Aristotle, and it is easy to miss because it hides inside the smallest word, "is." We treat existence as the dullest of facts: a thing either is or is not, and there is nothing more to say. Aquinas saw it as the most intense and mysterious thing about anything at all. In every created thing, he argued, there is a real difference between what it is, its essence, the kind of thing it is, and that it is, its act of existing, its esse. A unicorn and a horse have equally definite essences; the horse has the one thing the unicorn lacks, the sheer act of being. And that act, for Aquinas, is no static condition but the deepest activity there is, the act that makes every other act possible, the inner fire by which anything at all stands out from nothingness. In everything we meet, essence and existence are distinct, which means nothing here has to be; each thing receives its being from beyond itself. Only in one case could the two coincide: a reality whose very essence is to be, that does not have existence but is existence, pure act with no shadow of mere possibility in it. That, Aquinas says, is what the word "God" finally means: not a being among beings, however vast, but Being itself, the act of existing in its unlimited fullness. It is among the most vertiginous ideas in Western metaphysics, and it would sound again, seven centuries later, in Heidegger's question of why there is anything at all rather than nothing.

A law written in us. Aquinas brought the same confidence to ethics. There is, he held, a natural law, a moral order that human reason can read off our own nature with no need of revelation, rooted in a first principle as self-evident as any in logic: that good is to be sought and evil avoided. From the kind of beings we are the rest of its precepts follow, that life is to be preserved, the young to be taught, truth to be pursued, that we are made to live together, and a human law that violates this deeper law is, he says bluntly, no law at all but a kind of violence. The idea, which he took in part from Cicero and the Stoics, ran on through him into the modern language of natural rights and still anchors every appeal to a justice higher than the state. The room reads Aquinas in the old Dominican translation of the Summa, cited by part, question, and article; it is the largest body of work on the site, and you do not read it straight through but consult it, one article at a time, on whatever question you bring to it. For a thinker once feared as a dangerous innovator, who even saw some of his bolder theses condemned in the years just after, the reversal was total: six hundred years on, the Church made his philosophy its official teaching, and the twentieth century rediscovered him yet again, the metaphysicians in his theory of being, the moral philosophers in his recovery of the virtues.

It is fashionable to treat Aquinas as a museum piece, the supreme organizer of a medieval system the modern world has rightly left behind. But the thing that drove him is not medieval at all. He believed, with a steadiness that can look like serenity and is really a kind of courage, that the world makes sense; that no honest question is forbidden; that reason and faith and science and art are not rival tribes but partial views of one coherent reality; and that the road to truth is to give every position its strongest voice and then follow the argument wherever it leads. In an age that increasingly suspects nothing fits together, that values are mere preferences and the universe a brute accident, the Dumb Ox is a bracing and almost shocking presence, insisting that it all coheres, that being itself is intelligible and good, and that a patient enough mind can come to understand its own place in the whole. You need not share his faith to feel the pull of that confidence, or to suspect that a civilization which has misplaced it has lost something it will eventually have to go looking for again.