Intro to Thomas Aquinas

Thomas Aquinas (1225 – 1274) sought to find a workable fusion of Aristotle and the Church; nonetheless he strongly objected to Plato’s formulation of man as strictly a thinker and the Platonic abandonment of matter. In particular, Plato’s program consisted of separating “being” from “becoming”. What exactly is meant by being as opposed to becoming — who knows?1

It is the kind of philosophical mumbo-jumbo that drives people away from philosophy. Whatever the distinction is supposed to be, it’s probably a poorly chosen one. But let’s see if we can figure it out. Being, one must suppose, refers to abstract Form or Ideas existing in our minds (Plato was enamored of mental talk like this) while becoming must refer, in the Platonic canon, to material things: always changing, growing, decaying and generally being messy (something Plato wanted nothing to do with).

Plato’s attitude toward bodily things strikes me more as the product of mental illness than of a rational thought process. Only a diseased mind, cut off from the rest of the self or warped by infection or chemical imbalance, concludes that mental imaginings alone are real, that the body is nothing. Indeed there is something very unreal about such an attitude, something pathological. Nor is the foolishness of the Platonic attitude difficult to show even relying strictly on reason — which brings us back from parenthesis to Aquinas.

Aquinas understood the distinction Plato was trying to make between being and becoming, and he strenuously objected to it. Plato had to try to wash matter — the material world of bodies — out of the picture as if it didn’t exist. But it does exist, Aquinas said, and Plato’s philosophy can’t account for why.

If I understand him correctly, Aquinas maintained that Plato’s abstract ideas (the abstract idea of a tree, for instance) have in themselves (whether held in our mind or in God’s) absolutely no power to bring real, material trees into existence. The particulars of the world can’t be thought into being by thinking universals, no matter who is doing the thinking. But not being able to explain how matter comes to exists is only part of the problem. In the Platonic system, Aquinas saw, there could never be a satisfactory explanation of why matter exists.

To use more modern terms, Plato thought of us as a soul making incidental use of a physical body. We are decidedly not our bodies: they are just an impediment for the soul or mind that is the real us. Aquinas rejected this. We are, he said, a unity of body and soul, mind and matter. Both are equally essential if we are to be what God intended: spiritual beings who “know” the world.

Anton C. Pegis says in his book, Introduction to St. Thomas Aquinas,

Where the Platonic knower is a pure reason, and the Cartesian knower a pure mind, the Thomistic knower is, as knower, the composite of soul and body. Let us say this in another way. Man as a knower must be partly material in order to be adequately a knower.

Pegis follows this with a telling comment:

Of course, such a notion is bound to sound scandalous to modern ears. For we are the heirs of generations of philosophic speculations according to which man is a thinker and a mind. 2

For Thomas Aquinas a mind cannot “know” the world because the mind works in abstractions and universals, whereas the world is a population of physical particulars. The mind can only know — or think in terms of — these abstractions. We were given bodies, says Aquinas, precisely because we must have bodies in order to get our hands on particulars, to be a “knower” and not just a “thinker.” Pegis observes,

“…what we call the decline of mediaeval philosophy was really a transition from man as a knower to man as a thinker — from man knowing the world of sensible things to man thinking abstract thoughts in separation from existence.”2

Why Know the World?

Let’s summarize so far. Plato said the goal was to be a thinker thinking not about the material world (never real anyway), but about the eternal, nontransmutable ideas and ideal “Forms” — “the emptiness of abstract thought closed on abstractions”2 as Pegis believes Aquinas saw it.

Aquinas said a pure thinker can’t know the objects of the physical world: to do that the mind must be combined with a body. If our task was only to think, and not to know, then Plato’s scheme would suffice. Nonetheless it would not explain why we have bodies — or how they come to exist from universals.

Bodies are necessary to know the world. This is Aquinas’ key observation. Since we do have bodies, it follows, said he, that God created us with bodies because He intended for us to know the world.

But why? What is the purpose of knowing the world? Not, Aquinas maintained, for “the good of the body itself, since matter serves us rather than making us its servant.”3 Rather, it is because the soul alone “is unequal by itself to the task of accomplishing the work proper to an intellectual substance.”3

And this is where we part company with Aquinas. We don’t understand why — the real why — of existing as an “intellectual substance” with “work proper” to accomplish.

Why should God create us for such a task? What intellectual work does God need accomplished? Is it not work He could do Himself, and so much more quickly? Or is it because God lacks a body that He cannot do this work of “knowing” the world? — just as Aquinas maintained we humans could not do it if we were only Platonic thinkers.

This is a serious problem. How can God create a world — or even infuse a pre-existing material chaos with “order” — but then need us humans as body/soul beings to “know” this world? Doesn’t God “know” it already? If he doesn’t, how could He create it?

The Platonic story fails because it has to pretend that matter is not material — that it doesn’t really count. But why matter exists Platonism can’t begin to explain.

Aquinas bravely attempted to rectify this nonsense. But he leaves us without a way of explaining why the world must be known. Why does God need us for this task, and how can it be that God should need us for this task?

Now, maybe God doesn’t have to have a reason or purpose for creating the beings he peoples earth with. Perhaps God was just bored. “Let me create a creature with a mind and see if it can figure out the plan behind my world — that should be entertaining for a few thousand years, hopefully.”

But in all honesty, it wouldn’t be very entertaining, even for God.

If we want a solution that works, it’s pretty simple. All we must say is, “Yes, we have minds able to know the world, and we have them precisely for the benefit of our bodies.” This is the line of thought Aquinas summarily rejected, because he wanted the material body to “serve us rather than making us its servant” — thus he identified the body as “it” and the mind as “us”.

After all was said, Aquinas was unable to present us as a true composite. He fell back towards Plato.

Why Do We Have Minds?

We have a benefit Aquinas lacked: we know about evolution. This allows us to see immediately that the body can obtain a great survival advantage by developing a mind capable of knowing the world.

The mind exists for the benefit of the body. It comes into existence out of evolutionary pressure.

This answer, so obvious to scientists, does not appeal to philosophers and theologians. But it explains why we exist as bodies with minds — and this is something Plato and Aquinas cannot do.

Furthermore, evolution makes it clear that the body comes first, and the mind evolves after. We are not thinkers that picked up bodies along the way; we are not minds driving bodies around like they were automobiles; we are not ghosts in machines. We are living bodies that happened to develop minds.

To phrase it philosophically, evolution reveals that we must reject the primacy of the mind for the primacy of the body.

Now many philosophers post a very big objection at this point. They often voice it in terms of “free will” or “determinism” or “mechanism.” If we are bodies that through evolution developed minds, if the mind evolved physically, then that turns us into mere robots. We can’t have free will. We are reduced to a behavioristic and deterministic view of humankind which deprives us of any dignity. (One might think this objection is summed up nicely in the phrase “Beyond Freedom and Dignity” which is the title of a book by behaviorist B. F. Skinner.4)

But it is an objection based on their premises, not ours.

It is the Platonic, Thomistic, and Cartesian philosophers who have dunked the body down in the mud and elevated the mind up to the heavens. Today, presented with the idea that we are first and foremost bodies, they object, “You’re dunking us in the mud!” Depriving humans of dignity! they exclaim. Turning us into mechanisms!

No. That was their doing. Every time they pushed the mind higher and closer to God, they deprived the body of a little more dignity, pushed our faces a little deeper into the puddle. They propelled our mind up so high it obtained absolute free will, but correspondingly they denied our body almost everything: it became nothing but clockwork, deterministic, merely stuff for mind to manipulate and explain.

Turns out we were bodies all along.

Now we have to be rescued from this intellectual mud philosophers shoved us into. They denied bodies essence or real life, and now they object that in defining humans as body beings we are relegating ourselves to a lifeless state, without dignity, without value!

They are philosophically stuck on their own flawed premises.

But not just philosophers: most of us are stuck here. If it were just a few lifeless intellectuals, no one would care. But society as a whole is stuck, and it shows worst in our religious thoughts and ideas.

This is the crucial distinction between atheism and theism. Theism has decided that the physical world can’t stand on its own. It can’t because it is just “stuff” that obeys blind laws. Newton’s laws of motion for example; but really, any “laws” that scientists have discovered will do. Scientists discover these laws, but who created them? Since material “stuff” is raw, robotic, devoid on its own of value — because theists pushed value to a spiritual world — there must be something else to give this stuff value and laws to obey.

Then when atheists deny that there is a God or spiritual realm beyond our physical realm theists are shocked. To them atheists are proclaiming that we are nothing but raw, robotic stuff, devoid of value, obeying laws that never had a lawgiver!

If atheists were theists, this would indeed follow. If we remove God, a big hole forms in the universe.

But we are not theists. We are not Cartesians, we are not Platonists, we are not even Thomists. That’s the whole point: we have rejected their basic premises. No big hole forms where God used to be because our universe — based on our premises — never needed God to provide value or save us from mechanism in the first place. There’s no place for a hole.

Which means also there’s no place for God. No need. Value doesn’t come from without but within. Depriving us of value within — a result of theistic premises (so that it can be provided from without by God) — merely devalues us, and then makes us dependent on a questionable entity. And it shifts the purpose of life from earth and life to heaven and afterlife. Why does everything shift away from earth? Because our theistic premises have turned earth and our bodies into robotic, meaningless stuff — pushed all the meaning to heaven. Not here but in heaven will our life be fulfilled. And we must not really be bodies, but heavenly souls.

This is solely the result of theistic premises.

Atheists premises, on the other hand, leave us and our earthlife whole. Our bodies really are us and they really are valuable; they are not robots or mechanisms, and therefore we are not. Our life must be fulfilled here on earth, or never fulfilled at all. Thus moral behavior really matters — not because God will punish us in some imaginary beyond, but because moral behavior is necessary if we are all to obtain fulfillment on this blue planet of ours, which is the only place fulfillment is possible for us.

These premises are laid out elsewhere and perhaps don’t belong in an introduction to Aquinas. But to me it seems important as we approach Aquinas’ five ways5 (his “proofs” of God) to have a bit of background: that theistic premises are not the only premises possible, that there is a pleasing alternative to theism, that if there no God it is not a disaster. It might even open a new and better door.

The Nature of Knowledge

One atheist premise is that the nature of information (and the nature of the way human thinking works) makes it a logical fallacy to conclude that matter is a mechanism, or deterministic in any Cartesian sense. Truth is always a comparative, not an absolute. This means that scientific “laws” like Newton’s laws of motion are not laws per se, not bits of absolute truth however much we like to think so.

All scientific endeavour aims at creating useful descriptions of the world — which allow us to get things done successfully or open the door to future successful descriptions. These descriptions are hypotheses and we choose our hypotheses on the basis of how useful they are compared to competing hypotheses. How do we determine which hypothesis is more useful? By testing and replicating the test: in short, by the scientific method. If one hypothesis is consistently more useful, for our purpose at hand, than competing hypotheses, then we adopt it. If its usefulness over competing hypotheses is overwhelming, and if its consistency with related successful hypotheses leads us to feel we can’t imagine a more useful challenger, scientists will call it a “theory.” If it seems to cover a basic and useful relationship of things, it might even be called a “law.”

But we mustn’t forget that all theories and laws are nothing but very successful, well established hypotheses. They are not absolute truths. They can never be, for the method doesn’t allow that kind of a determination. Why? Because hypotheses are always tested for usefulness against other hypotheses. Laws compete against other laws: all scientific ideas are verified in competition with other ideas.

It is important to note that there is no way to verify science directly against the world itself, except by the process of comparative usefulness. This hypothesis worked, it was useful; that hypothesis did not. But just because one works doesn’t mean a third hypothesis might not also work. In such a case scientists create controlled experiments to test both hypotheses and determine which one is more useful more often.

This is how science works. It runs on the premise that truth is a comparative, not an absolute. If there is absolute truth out there, science has no way of confirming it. It can only confirm comparative truths.

Science works, in other words, precisely because it abandoned the old philosophical tradition of trying to divine absolute truth. In thousand of years, on the other hand, philosophy has made little progress. It is as much a mess as ever. Why? Perhaps because it has failed to recognize that truth is relative, and that hypotheses can only be verified by their usefulness compared to competing hypotheses.

Now, atheists hypothesize that there are no absolute truths about the world. There are, of course, millions of absolute truths bumping around in our heads. All thoughts have an absolute kind of quality, but that is the nature of thoughts. The question, however, is whether any of these absolute thoughts match the real world. The atheist premise is that they do not, and they cannot. To put it another way, there is a mismatch between information and the world itself.

In this world as atheists imagine it to be, the scientific method is the only way to knowledge because it is optimized for discovering comparative truths. Optimized, that is, for the specific kind of world atheists postulate: a world with no absolute truths, with a mismatch between thought or information and the physical world itself, and a human mind that evolved over millions of years not to discover absolute truth, but to develop practical, useful hypotheses about the world.

This hypothesis about information may seem remote from atheism, which after all is only the denial of God. But when we study Aquinas and his five ways5, we’ll see why this is indeed at the core of atheism. It is not enough to deny God; we must also overthrow the theistic premises that underlie belief in God. An atheism that rejects God without rejecting the underlying premises of theism is doomed to self-contradiction.

Once we understand what thought is we realize that rather than being primarily a “knower” — though that is a part of us — we are primarily “behavers” and “experiencers” in a phenomenal world that is in an absolute sense unknown and unknowable. This is simply because it is not informational in nature, whereas the mind’s modus operandi is by necessity informational. Yet this mismatch makes no practical difference to science. (But it makes a huge difference to philosophy and religion.) The whole genius of our mental processes is that they are ideally suited for developing useful hypothesis in comparison to alternatives and testing them by their usefulness — and the nature of the world itself simply doesn’t matter.

There is no paradox here. the practicality of the human mind, and of its scientific method, is in line with what we should expected from evolutionary pressures, which are inherently biased toward what is useful, what works. Evolution provides a completely consistent and testable explanation of the origin of our minds and the mental currency of information, and why human thinking takes a form optimized to “know” a non-informational world.

For Aquinas, we have bodies because bodies are necessary to serve the mind in its quest to know the absolute truths of God’s world. For atheists, our minds exist because we are bodies, and because developing minds was a practical and useful benefit under evolutionary pressures. For Aquinas and theists, real meaning and value come from heaven; for atheists they come from earth and from us. For theists, our lives are a temporary stop on our way to God’s realm; for atheists life is all there is or need be and afterlife is a cruel deception. For Aquinas life without God is worthless; for atheists the concept of God renders life worthless.


1. Aquinas picked up this distinction from “The Consolation of Philosophy” by Boethius (480 – 524) See Philosophy in the Middle Ages, edited by Arthur Hyman and James J. Walsh, Indianapolis: Hackett Publishing Co., 1974, p.115: “One of Boethius’ many incisive statements gave rise to another distinction much discussed by later medievals. Commenting on the difference between God and creatures, he states that in beings other than God, ‘being’ (esse) and ‘that which is’ (id quod est) are different. In making this distinction Boethius has in mind that while individual substances are composed of various parts, none of these parts make a substance to be what it is. Its determinate characteristic is provided by a unifying and determining principle–its being (esse). Though, for Boethius, this distinction serves only to describe the relation between a substance and that principle which makes it to be what it is, Aquinas finds in it a supporting text for his own distinction between ‘essence’ and ‘existence’.” Aquinas may also have been indebted to other Aristotelians such as Avicenna (980 – 1037) and Averroes (1126 – 1198). For example, on page 283 of Philosophy in the Middle Ages, we read: “Analyzing substances existing within the world, Avicenna had distinguished between their essence and existence, affirming at the same time that essence is ontologically prior to existence and that existence is something added to essence….Rejecting this Avicennian distinction, Averroes held that individual substances exist primarily and, though the mind can distinguish between essence and existence in them, ontologically speaking, the two are one. Thus, while for Avicenna essences were primary, for Averroes primacy belonged to individual substances.” Finally, someone with a bit of common sense!

2. Introduction to St. Thomas Aquinas, edited by Anton C. Pegis, NY: The Modern Library, 1948, p. xxiv

3. Introduction to St. Thomas Aquinas, edited by Anton C. Pegis, NY: The Modern Library, 1948, p. xxiii

4. Skinner, B. F. Beyond Freedom and Dignity, Bantam Books; 11th Print edition (1972)

5. In his Summa Theologica, Thomas Aquinas presented five “ways” by which the existence of God could be proven. (It is not to be thought that these proofs originate with Aquinas. Most can be found in Islamic, Jewish, and Christian philosophical traditions well before Aquinas.)

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