Descartes is Lame

I’ve finished the first chapter of my summer reading project. I have read Descartes’ Meditations on First Philosophy, along with several commentary essays on Descartes and on the Meditations particularly (from the Cambridge Companion to Descartes). He wrote widely about all manner of things, from geometry to physics to the existence of God. Fortunately, the Meditations provide a concentrated dose of his philosophical positions, clocking in at 64 pages in the Oxford World’s Classics edition. Even knowing how slowly you have to read philosophy, though, I was surprised by how easily I got bogged down. Anybody who discusses philosophy is familiar with some Cartesian arguments and conclusions, but it still takes dedication to get through the arguments bit-by-bit.

I could scarcely do justice to the foundational work of modern philosophy by cataloging all my impressions, which have no doubt been written elsewhere before (and which I will no doubt encounter all too soon in Hobbes and Locke). But I will note my predominating impression, which has to do with method.

Philosophers usually define philosophy as the attempt to answer certain questions rigorously – timeless, fundamental, in some sense unanswerable questions. It has very well-defined subfields clustered around different kinds of question. The three largest are metaphysics (the investigation of spiritual questions); ethics (the investigation of moral questions); and epistemology (the investigation of the question, how do we know things?) The Meditations, I found, place the three subfields in an interesting and problematic relationship to each other.

Descartes begins the Meditations with a position of extreme skepticism – doubting even the existence of material objects – in order to get to what is really, undeniably true. Thus, his project is epistemological. His most famous dictum is, after all, “I think, therefore I am.” Yet Descartes soon comes to the belief that his attempts at an epistemology depend on the existence of God. He proceeds from the assumption of his own existence, since he cannot prove the existence of anything else. But in order to prove anything else, he must combine that fact with other self-evident truths. And what if our belief in the principles of addition, for example, are just as suspect as our belief in the external world? If God exists, he could make us such that we believed pretty much anything he wanted us to.

I cannot help admitting, that, if indeed [God] wishes to, he can easily bring it about that I should be mistaken, even about matters that I think I intuit with the eye of the mind as evidently as possible

[…]

In order to remove [this doubt], then, at the first opportunity, I must examine whether there is a God, and, if there is, whether he can be a deceiver; since, as long as I remain ignorant of this matter, I seem unable ever to be certain of any other at all.

So Descartes moves from an epistemological question to a metaphysical question. Does God exist, and what is his character? He spends the rest of the Third Meditation developing his proof of God’s existence, which goes more or less as follows. Since all things must have a cause, and the cause must be as real as the thing caused, then our minds must have real causes. Since our minds are thoughts, they must come about from thoughts which are at least as real as they are, and which contain at least the same content (since something cannot come from nothing, the idea of a stone cannot come from a thought that does not have the idea of a stone already in it). Finally, since I am capable of producing the idea of a perfect and infinite God, even though I am neither of those things, it logically follows that such a God exists and caused my mind to come into being. Descartes includes a number of other logical steps which make his argument sound slightly less silly to modern ears, but that’s it in a nutshell. The key point is this: when it comes to establishing not just that God exists, but that he does not deceive us about fundamental logical principles, Descartes simply says that a perfect God would not do such a thing. That’s it; two sentences for the linchpin of Descartes’ whole argument (in my opinion). Here they are:

The whole force of the argument comes down to this, that I recognize that it cannot be that I should exist, with the nature I possess (that is, having the idea of god within myself), unless in reality God also exists – the same God whose idea is within me, that is, the one who possesses all the perfections that I cannot comprehend but can to some extent apprehend in my thinking, and who is subject to no kind of deficiency. From this it is sufficiently clear that he cannot be a deceiver: for all cunning and deception presuppose some shortcoming, as is plain by the natural light.

I find this paragraph utterly amazing. In a work known principally for its radical, pervasive doubt, the central ethical question of what a perfect God would do, and what should be the case in a justly governed universe, is completely glossed over, and the answer assumed a priori. Descartes goes through intellectual contortions to prove God’s existence. He is willing to assume, however tactically, that his most cherished belief is a lie. Yet once he has that proven to his satisfaction, he answers the further question of God’s nature with unexamined moral assumptions.

Leaving aside the impact of that omission on Descartes’ argument, I think its implications for philosophy in general are significant. The glossing-over of ethics in the Meditations is just a particularly striking example of the interdependence of the different philosophical subfields – and the not-always-objectionable practice of assuming one to proceed with the other. In order to make any ethical investigation, for example, you first have to assume some things about what humans are; what human nature is; whether God exists; if so, how he interacts with the world; etc. And in order to make epistemological claims, as Descartes points out, you have to make metaphysical claims.

And in this case, in order to substantiate a metaphysical claim, Descartes has to make certain ethical assumptions. Why would it be wrong to create deceived beings? What is God’s purpose in creating things in the first place? Is there a natural law to which God himself is subject? I find often that religious discussions about the existence of God hinge on exactly this sort of question. Take the old complaint, why does a just God allow evil things to happen? When someone’s belief in God is troubled by the injustices in the world, they probably conceive of God as a king-like figure who rules over the universe justly. That’s who God is, to them, and if you challenge the justness of God – that is, God’s moral responsibility for the state of the universe – then you challenge the existence of God. Because he wouldn’t exist if he weren’t just.

It’s worth remembering that the biggest philosophical question, to most people, is not, “how can I tell if I’m in the Matrix or not?”, but “what is the meaning of life?” In my opinion, we tend to subordinate questions of knowledge and spirituality to questions of ethics. The most common example is above: we assume a just God. That’s not necessarily so, of course; but if it isn’t then life has no meaning (to the people who assume a just God). And if we can’t give life meaning, well…there’s no point in doing anything else. To be fair, Descartes eventually suggests a meaning for life by encouraging us to contemplate the perfection of God. But I think he shortchanges ethical questions a great deal by failing to explain God's perfection - and I think he does so because he is unwilling to challenge his deeply held moral assumptions about the nature of God. For that reason, the Meditations left me with an impression, more than anything else, of hollowness.