Thomas Aquinas: An Overview

Frederick Copleston was my first guide through most of western philosophy. I read his whole series The History of Philosophy a couple of years before I traveled to India in the mid-1980s. Library copies. I bought my own nine-volume set much later when I could afford such things and I still go back to different sections of it every year to brush-up on something.

Copleston introduced me to Sartre, Nietzsche, Kant, Hume, Plato and Aristotle, Aquinas and Ockham. In almost every case I met the philosopher through Copleston before I either read him directly or ran into some other major interpretation. William Barrett's Irrational Man was another early door into Nietzsche and Sartre, for example. But Copleston gave me the whole history, the Greeks to the mid-twentieth century.

I made a New Year’s resolution to reacquaint myself with Thomas Aquinas. Don’t ask me why. There are a lot of great minds I could have chosen. But it has been a couple of decades since I last delved into his philosophy. I studied a little Augustine years ago, which I blogged about here. It just felt like time to revisit an early Christian philosopher.

Of course, I didn’t intend to actually read Aquinas himself. I don’t know much Latin. Ha ha. So this is Aquinas as Copleston presents him. Aquinas organized his own writing by theological and philosophical purpose. Copleston is explaining Aquinas to a contemporary reader inside a larger history of philosophy.

His sequence is revealing. He starts with Aquinas the man, separates philosophy from theology, moves through the principles of created being, the proofs of God's existence, God's nature, creation, psychology, knowledge, moral theory, political theory, and finishes with the trouble caused by trying to marry Christianity to Aristotle, including the opposition Aquinas caught in his own lifetime.

Copleston covers the basics (the education, the understudy with Albert the Great, the entry into the Dominicans, the staggering output) and then mentions Aquinas's "fits of abstraction." Even if crowded or in the middle of a meal he would simply go into a kind of trance. Later he'd surface with some exclamation about a discovery that had nothing to do with whatever was happening around him.

He was noodling out and he did not care what was going on for a few moments. Thomas Aquinas was strange.

But this reveals something about how his mind worked. Aquinas could withdraw and stay absorbed for long stretches in causation, existence, form, matter, intellect, will, God. The "Dumb Ox" (he was teased as a monk because of his robust size) was apparently thinking most of the time.

Copleston calls him an innovator. Easy to forget, since Thomism later became a synonym for Catholic tradition and institutional safety. Aquinas didn't start out safe. He was tinkering with a system a lot of traditional Christians considered dangerous.

Without Albert the Great's precedent, he might have been condemned outright instead of merely suspected. Albert opened up the breadth of Aristotle to medieval Christianity. Aquinas saw further. Aristotle was the most powerful, most comprehensive intellectual system the medieval world had access to. It was 1,500 years old. He saw the turning it down (as most Christian thinkers did including Augustine) meant turning down the strongest philosophical system on the table. Aquinas saw how it could be used to build a Christian synthesis of enormous range.

Augustine Christianized Plato. Aquinas Christianized Aristotle.

Broad shorthand, but it’s solid. Augustine works from a Platonic and Neo-Platonic orientation. His movement is inward. The Confessions opens with the self, memory, time, desire, sin, will, the soul's relation to God. Aquinas is built differently.

Copleston begins explaining the philosophy with corporeal being. Aquinas starts with the physical world, though "physical" meant something much wider to him than it does to us. He starts with things that change. Matter and form. Potency and act. Essence and existence. Human knowledge begins in the embodied experience of a world.

Where Augustine moves inward toward God, Aquinas starts with what's physically standing in front of him.

Copleston tells us that hylomorphism sits underneath all of it. Corporeal things are composites of matter and form, not a thing plus some separate form hovering nearby. The being is the composite. Potency and act explain change: something capable of becoming actual has that capacity potentially, and change is that potential becoming actual.

Essence and existence take it further. Essence is what a thing is. Existence is that it is. Created things don't contain their own reason for existing. Their essence doesn't explain why they exist at all. Copleston is careful on this point: "Created existence and essence arise together, and although the two constituent principles are objectively distinct, existence is more fundamental." (Vol. 2, page 334)

Essence isn't sitting somewhere waiting for existence to show up. A created thing exists as a particular kind of thing. The two arise together, but existence is the more tangible of the two. That turns out to be Copleston's on-ramp to the Five Ways, Aquinas’s famous proofs of God. Aquinas has started with created being. Now Aquinas asks what the existence and activity of that being requires.

To be such a big deal, the Five Ways are shorter than you might expect. Aquinas doesn't make the fuss over them that later defenders and critics have. The first gets the most elaboration; the rest are compressed. Copleston presents them the same way, he devotes more words to the first proof than any of the others.

Aquinas starts from motion. Whatever moves is moved by another, and the series can't regress forever. We arrive at an unmoved mover, which Aquinas declares "and all understand that this is God."

The second is efficient causation. Nothing causes itself, since it would have to exist before itself to bring itself into being. No infinite regress of causes explains the present series. There must be a first efficient cause, "which all men call God."

The third is contingency. Things come into existence and go out of it. None of them had to exist. There must be a necessary being, or nothing at all would exist.

The fourth runs from degrees of perfection. Degrees of goodness, truth, and perfection imply a best, a truest, a supreme.

The fifth is directedness. Unintelligent natural objects still act in regular ways toward particular results, and Aquinas compares it to an arrow guided by an archer. Something intelligent has to be doing the directing.

Of course, Copleston goes into far more detail than what I just summarized and directly quotes Aquinas’s Latin. For me, these proofs are silly and strange. Why did he feel like he had to prove God existed logically? Why was that even a thing? Most everyone did their own riffs on this. It is sort of like an inherent nervous tick in the history of philosophy. Of themselves, they are not as interesting as what Aquinas does with them.

Perhaps surprisingly, these arguments do not get you to the Trinity or Incarnation or anything specifically Christian. Instead, Aquinas takes us to necessary Being. Reason starts with created being and moves toward God. Revelation supplies what unaided reason can't reach.

One more comparison from Copleston is noteworthy: the "interiority" running through Augustine and Bonaventure's proofs (bedrock of Catholic thought) is absent here. Aquinas could have applied the same principles to the self. He doesn't. Motion, cause, contingency, gradation, direction. The world comes first. This is what he learned from Aristotle and, for obvious reasons, it is something traditional Christian thinkers frowned upon.

Once necessary Being is on the table, Copleston moves to God's nature. Existence doesn't hand you essence. Aquinas finds God in the world, in the natural perfections we discover in this world: "We cannot in this life know the divine essence as it is in itself, but only as represented in creatures, so that the names we apply to God signify perfections manifested in creatures." (page 352)

Which makes analogy his method. We know creatures. Creatures are God's effects. The perfections we find in them reflect their cause, imperfectly and in different ways, and our language about God grows out of those reflections. Good, intelligent, wise. These can't mean exactly the same thing applied to God as applied to us, or God becomes an oversized creature. They can't mean something totally unrelated either, or the words say nothing.

Analogical predication sits in between: real knowledge, inadequate knowledge. Copleston's example, on divine intelligence, is worth keeping close to his own words: "Our knowledge of the divine intelligence is imperfect and inadequate, but it is not false; it is analogical knowledge." (page 357)

Creation follows from God's nature. A necessary, perfect Being needs nothing outside itself. Creation can't fill some lack. "He created, not in order to obtain, but to give, to diffuse His goodness." (page 365) Creation is that diffusion, and it's also where Aquinas has to deal with suffering and death.

God wills a sensitive nature capable of pleasure, which means a nature capable of pain. He wills a universe of different levels of being, some of them corruptible, and corruptible things die. Aquinas treats physical evil as something willed indirectly, for the sake of the whole: "God may be said to have willed physical evil not per se but per accidens, for the sake of good, the good of the whole universe." (page 373) The variety of the created order requires mortal, sufferable natures. That's the account.

Human psychology comes next, in the same order. God creates the world, then we look at the creature inside it. Aquinas follows Aristotle's levels of life: vegetative (nutrition, growth, reproduction), sensitive (locomotion, appetite), rational (active intellect, passive intellect, will). Human beings hold all three at once, the higher including the lower.

The will is naturally aimed at the good. That doesn't mean every choice is good. It means the will seeks whatever looks desirable under some idea of good, and its final target is happiness, beatitudo. We can't help wanting to be happy in that broad sense. What we're free to choose is the particular path to it.

Aquinas also insists on the unity of the human being. No separate soul running a body like a machine. One substantial form, the rational soul, accounting for the vegetative, sensitive, and rational activity of the whole composite. Sensation belongs to the compositum, not to the soul alone. Mind depends on sense experience for its knowledge.

Knowledge follows directly from psychology. The intellect abstracts universal concepts from sensory experience, but the concept isn't the object known. It's how the object is known. When I know a tree, I'm not contemplating my private idea of a tree. The concept is the means, not the destination. And the intellect needs the phantasm, the image tied to sense and imagination: "the human soul... understands nothing without a phantasm." Nothing is in the intellect that wasn't first in the senses.

Which is why Copleston opened with corporeal being in the first place. Human beings are embodied composites whose knowledge starts in sensation. Aquinas starts where he thinks the mind actually starts.

Moral theory follows psychology and knowledge for the obvious reason. Once you know what a human being is, how the will works, and how it knows, you can ask how it should act. Here the limits of Aquinas's Aristotelianism show up. He uses Aristotle's language and much of his structure, but Christianity has the final say. What Aristotle calls happiness, Aquinas downgrades to imperfect or temporal happiness, ordered toward a perfect happiness attainable only in the next life, the vision of God. Aquinas "utilizes the Aristotelian ethic but fits it into a Christian setting." (page 402)

Human nature has a natural appetite for some contemplation of divine things through its own powers. The full supernatural end is beyond those powers. Grace has to do that work. Every deliberate act either lines up with the order of reason and the final end, or it doesn't, and that's the whole moral ledger: good or bad. Moral virtue's job is to bring the appetites into line with reason.

Reason gives access to natural law, but passion derails it, and most people don't have the time or the ability to work natural law out for themselves. That's why Aquinas thinks positive divine revelation is morally necessary. The Decalogue expresses the natural law. Supernatural law points beyond natural capacity, "since man is destined to the end of eternal beatitude, which exceeds the capacity of human natural faculty." (page 409)

Aristotle's unmoved mover doesn't create the world, doesn't govern it, doesn't have a relationship with anyone in it. It's a final cause absorbed in its own self-contemplation, the noblest object of contemplation but nothing more personal than that. Aquinas has carried Aristotle's own machinery a very long way past Aristotle.

Political theory follows moral theory, because human beings live together. And Aquinas's Christianized Aristotelianism pulls him away from the Augustinian habit of explaining the State through original sin. Political society is prefigured in human nature. Human nature is God's creation. So the State has its own legitimacy, its own end, its own sphere. It isn't the product of sin, and it isn't just egoism organized. It's a communitas perfecta, a complete society with what it needs to reach its own end: the common good, peace among citizens, provision for the needs of life, defense, protection from crime.

The Church holds the higher, supernatural end. The State stays autonomous within its own lane. Aquinas has no logical route to turning the Church into a super-state or political government into a Church subsidiary.

He follows Aristotle in sorting good governments from their corruptions: lawful democracy, aristocracy, monarchy on one side, demagoguery, oligarchy, tyranny on the other. Monarchy is his ideal, best for unity and peace, though he knows the ideal monarch is hard to find. The best practical government mixes monarchical power with magistrates elected by the people.

The bees have their monarch. God rules creation. Apparently even medieval political theory needed bees.

Authority is bound by reason and by the purpose it exists for, a father's authority over a household, a sovereign's over subjects, all of it derived from God and none of it license for arbitrary rule over another rational creature. "The State is neither God nor Antichrist: it is one of the means by which God directs the rational embodied creation to its end." (page 422)

Aquinas used Aristotle to build something extraordinary, and Aristotle and Christianity were still pulling in different directions the whole time. For the Aristotelian, the universal and the totality are what count: the view of a physicist, partly of an artist. For the Christian, the individual has a supernatural vocation, a personal relation to God, a final beatitude no earthly society or natural effort can reach. "Each human person is ultimately of more value than the whole material universe." (page 428)

Aquinas systematized both orientations without erasing the tension between them. That was the genius. It was also the danger.

Traditionalists thought he was giving away too much to Aristotle. Some tried to fold Thomism into the condemnations aimed at Averroism. The man now presented as a pillar of orthodoxy was, in his own century, accused of importing dangerous novelties. Copleston: "it is useful to remember at a time when Thomism stands for tradition, for theological soundness and security" that St. Thomas was once "regarded, by hot-heads at least, as a sower of novelties." (page 431)

Copleston is a Catholic priest writing about one of Catholicism's greatest minds, and he doesn't spend these hundred pages defending Aquinas. He contextualizes him: the world Aquinas walked into, the problems he inherited, the Aristotelian tools he picked up, the Christian ends he bent them toward, and the tension that never fully resolved.

Thomas was an odd duck. He was also brilliant and fresh for his time. Making Aristotle fit Christianity seemed almost heretical back in the 1200’s. It seemed logical to Aquinas which, as it turned out, just might have salvaged Aristotle for western civilization.

(to be continued)