Descartes’ Ontological Argument And What It Means For How We Understand Philosophy

Descartes’ Ontological Argument And What It Means For How We Understand Philosophy January 2, 2015

The ontological argument is the red-headed stepchild of philosophical arguments for the existence of God. Plantinga’s and other contemporary versions, like everything having to do with modal logic, seems to confirm Wittgenstein’s indictment of philosophy as a language game. For all that I have tried to rescue it, Anselm’s really seems like the caricature of it (Aquinas certainly seemed to think so, and he would know better). Most of the time, when something a philosopher writes looks obviously stupid, you’re the one that’s stupid–but not always. And Anselm’s only defined God as a being, which is not the fullness of being of classical theism; ens summum rather than ipsum esse subsistens.

But Descartes’ version, which might be the least-mentioned, is actually very good; in fact, in my view, the best version of it, and a profound one. I should say at this point that this post isn’t about arguing for the existence of God, but rather about what this says about philosophy–that Descartes’ argument is good, and yet under-rated.

There are two things to understand about Descartes’ argument. The first is that Descartes, like pretty much every philosopher up until, well, him, was a mathematician as well as a philosopher. The second is that the argument appears in a little book called Metaphysical Meditations. More on the second point later. But first, the first point.

The ontological argument is usually presented as such: God is the highest being that can be conceived; since a being that did not exist would not be the highest being that can be conceived, God must exist. It obviously looks silly.

Violently compressed, it comes out much like this: because we can conceive of God, he must exist.

But this is where Descartes comes in. As a classically trained mathematician, he understood things like Euclidian geometry. And he understood that what is even conceivable in any given geometric universe is determined by the axioms that rule that universe.

For example, if you decide that you’re doing geometry on a two-dimensional plane, spheres don’t just not exist, they’re not even conceivable within a two-dimensional plane. There’s no way to even describe them in two-dimensional geometry.

If you’re able even to say “Imagine a sphere”, then it must mean by definition that you live in a universe with at least three dimensions, because otherwise such a thing would be not just impossible but inconceivable. And in fact, it’s perfectly possible for us to imagine a sphere even though none of us has encountered a perfect sphere–but it does tell us that we live in a universe that has at least three dimensions.

Is everyone still following?

If you have that mode of thinking in place, it actually becomes quite significant that we can even imagine that there might be a God. After all, it’s perfectly possible to imagine a Universe pretty much like ours where no one would imagine that there is a God–a Universe with an Earth where no primates ever developed self-consciousness, or a Universe made up of unselfaware Sims who don’t ask questions about the meaning of life. But that’s not the Universe we live in. We live in a Universe where we can imagine spheres, and the possibility of God.

Therefore, the fact that we can imagine God as the highest being there is is very good evidence for the existence of God.

But wait a second, you say. You might have proved that it’s possible to imagine God, but you haven’t proven that he exists. Just saying that a sphere is conceivable doesn’t actually prove that a sphere exists.

A-ha, but see, here’s the thing: Descartes knew his classical theism, and he knew that God is not one thing inside the Universe, but rather the precondition of that Universe, its uncaused cause, the fullness of Being, pure act without potentiality (you know the drill). God is to the Universe like axioms are to geometry. And so just like the fact that we can imagine a sphere necessarily means that we live in a Universe with at least three dimensions, because otherwise the thing wouldn’t just be hypothetical, we would be unable to even conceive of it, the fact that we can imagine God actually means that God must exist.

What to make of all this?

Again, the point here isn’t to “prove” the existence of God. But I like to write about this because I find it fascinating for a couple of reasons.

The first is that this argument gets egregiously misunderstood by contemporary philosophers, and for a rather important reason. Back in Ye Olden Days, almost all philosophers were trained mathematicians, and mathematics and philosophy were considered to be sister sciences, since they both dealt with abstract, universal truths arrived at through logical reasoning. It all dates back to Pythagoras, he of the theorem, but also the true founder of philosophy and Plato, who was his student (an enormously significant fact for his philosophy–and therefore all philosophy–that almost no one cares about). Mathematics was a required subject at Plato’s Academy, and you were required to attain a certain level before you were even allowed to study philosophy.

Today, let’s face it, most philosophers are people who got into philosophy because they sucked at math (myself very much included). But this means that a lot of background assumptions that all philosophers shared up until roughly the 19th century have been lost. I think most people would agree, at the very least, that Descartes’ ontological argument looks much better the way I’ve laid it out than the way it’s usually presented–but even Kant (who hated mathematics as a boy) misunderstood it and offered a critique that I think misses the mark.

Of course, if we missed stuff that would have been that obvious to Descartes’ predecessors and contemporaries, the scary question arises: what else are we missing? A lot.

The second point is that if even my unpacking you still think Descartes’ argument is weird, I don’t blame you–and neither would he. You see, the argument appears in a book titled Metaphysical Meditations. Emphasis on the second word.

Descartes is often described as the first Modern philosopher, but one little trick I’ve found for those “hinge” figures is that often the best way to understand them is not as “the first [X]” but as “the last [thing that came before X]”. For example, Augustine is often called “the first modern man”, but he was also “the last of the Romans.” (Was Chateaubriand “the first romantic” or “the last classic”? You have four hours.)

In many ways, Descartes was not just the first Modern philosopher but also the last Ancient philosopher, and the classical understanding of philosophy was that of a process. Philosophy was not so much a doctrine as a way of life, of questioning, of thinking rationally–ideally embodied, of course, by Plato’s Socrates. Descartes’ ontological argument, even when it was explained to me, and even as a theistic believer, still stuck me as unbelievably odd. But you have to sit with it. After a while, it does start to nag you. Why is it that human beings have this notion of the infinite, of the beyond the beyond, of the unconditioned good? Doesn’t that just say something about the nature of reality, and not just our psychology, that these things are even conceivable? After all, in a two-dimensional world, spheres aren’t even conceivable…

Even Aquinas, usually thought of as the ultimate “A+B=C” rationalistic thinker didn’t call what everyone else calls his “proofs” “proofs”, but rather ways. The most important fact about the Summa is that he wrote it as a textbook for the training of priests. It isn’t a reservoir of Platonic-like abstract truths about theology, no matter how much Thomists want to treat it like that, it is a pedagogical text. Aquinas isn’t so much interested in “proving” the existence of God (neither he nor the seminarians he wrote for need any proof!) as of using these arguments as paths towards a greater knowledge of God*. The value of the cosmological argument is not so much in being a “proof” as in causing readers to meditate on the notion of God, not as some sort of superbeing or demiurge or Spaghetti Monster, but as the unconditioned cause of all there is, the perfectly transcendent fullness and ground of all existence. The Five Ways are only the appetizer for the introduction of the via negativa and the attributes of God.

Christianity unwittingly dealt a mortal blow to this understanding of philosophy, by treating the Ancients as a reservoir of concepts they could repurpose to do theology, and in the practical realm by privileging the Christian way over the philosphic way, but the coup de grâce was administered by the Moderns and their rationalistic project.

When Wittgenstein wrote that all philosophy is just a language game and thought he had thereby solved all philosophy, he behaved rather like the fellow who shows up at a costume party and informs the host that despite his powdered wig he is not Louis XVI because Louis XVI died over two hundred years ago–utterly correct, and utterly beside the point. Of course it’s a language game, Socrates would have patiently explained, a smile on the corner of his lips, but that’s the whole point–playing this sort of language game is part of what it means to be human, and you have to play it if you can ever hope to attain the good life. That’s what this whole “examined life” business is all about, after all. And the fact that it’s a game doesn’t mean you can’t win real prizes–real truths–once in a while. (Of course, he would not have explained it so straightforwardly–that’s the whole point.) I mean, have you ever even read one of Plato’s dialogues? That’s why they’re dialogues.

No, the really astonishing, and sad, part is that so many people thought Wittgenstein was such an earthquake. (Don’t get me wrong, he was astonishingly smart, and made very good contributions to the philosophy of language.) But the reason why is the same reason why you will not find a good treatment of Descartes’ ontological argument in contemporary secondary literature–so much of philosophy has simply been forgotten, or overwritten by smug assumptions about what we oh-so-clever people with our airplanes and penicillin have figured out that those benighted bearded people were too backwards to understand.

In a sense, Plantinga’s version of the ontological argument is the reductio ad absurdum of the whole contemporary approach to philosophy: to it, Blaise Pascal’s judgement on Descartes’ proof, “useless and uncertain”, truly applies. I don’t know what Descartes’ meditation “proves”, but at least, when approached with the right spirit, it draws into a contemplation of the nature of existence, and that’s not so bad. I don’t know that you can say the same thing about anything with the words “modal logic” in its Wikipedia entry.

(Hang on a second, you might ask: if people don’t get Descartes’ argument because they don’t get math, then how come Pascal–who certainly was no slouch in the area–thinks it’s bad too? Three possibilities, in my view: (A) I’m missing something, which is quite possible, in which case half this post is junk; (B) most of Pascal’s writings come to us from stray notes that he left behind after he died, many of which he probably never intended to publish, maybe he really didn’t mean it; (C) most likely in my view, Pascal’s project of Christian apologetics was profoundly shaped by his own fiery, mystical experience of conversion, and the goal of his apologetic writings was never so much rational demonstration or “metaphysical meditation” in the philosophic sense, but rather to get a primarily emotional response of existential tremor which I think he believed was the thing that led one to faith (how Jansenist); for this project, then, Descartes’ meditations are definitely “useless and uncertain.”)

One of the most entertaining parts of The Experience of God is how mightily Hart, who probably has the same reservations as I do towards the ontological argument, struggles to rescue both Anselm and Plantinga from the morass they created for themselves. The ontological argument is a tricky beast, and I do think, even if he understood Anselm better than Anselm did (which isn’t unlikely), Aquinas was wise to discard it. Although I do think that in its Cartesian form it is, well, first, correct, but more importantly, profound, precisely as a metaphysical meditation.

P.S. Read Flatland.

* Don’t get me wrong, Aquinas totally believed in the value of natural reason and in the validity of his Five Ways. But, clever dog that he was, he was working on several levels at once.

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