Renee Descartes: Not a Bad Philosopher. A Bad Physicist.

It is fashionable these days to “not believe in dualism,” though typically, if the conversation deepens, what is believed in its place turns out to be vague. Ask someone to explain – precisely – what they believe instead of dualism, and they often end up sounding like Obama in his first debate with Romney. There’s a lot of jaw movement, but no sound coming out.

This isn’t their fault. Dualism, while wrong, “works.”  It gets rid of all the confusion and illogic of the mind-brain problem up front, brackets it, and then proceeds logically from there. But non-dualism doesn’t work. It sounds nice; it’s very comforting. But it doesn’t work. There’s no there there. It doesn’t mean anything to say “I believe the mind and the brain are the same thing,” since Descartes had the obvious advantage of knowing that the mind and brain are definitely, definitely, definitely not the same thing.  Why, I can take a nail to the brain and my mind will never feel it. I can desperately need neurosurgery and have no idea. Meanwhile I can be desperate for clams without my brain showing an iota of change. Is that the same thing? Nooooooooooo. Is dualism helpful in explaining this? Yessssssssssssss.

But there is a better way to beat dualism than not believing in it philosophically. You can go back to its roots and show that it was premised on an understanding of physics that was missing – more or less – half the universe. In  The World. which I had never heard of until yesterday, Renee Descartes gives some of the physics background on which his dualistic theory was premised. And you needn’t get more than 100 words into the thing before – if you like dualism – you will start to get an awfully sick feeling in the pit of your stomach.

It’s the same feeling Andrew Sullivan is getting about Obama this morning – when you start to realize your hero is way, way off his game. Or maybe that’s a bad analogy. It’s the same kind of sick, sinking feeling that a college Freshman chemistry student might get after sitting down with his study buddy and realizing, after the guy says a few words, that he doesn’t know that chemical bonds are electronic – that they are made by electrons. And then realizing, wait, this guy doesn’t know about the electromagnetic force per se. And then realizing, Holy Shit, not only is this guy going to fail tomorrow’s test, but if I keep studying with him he’s going to take me down with him.  It’s a desperate feeling to get out of the room, to get away before the fellow’s ignorance destroys you – it’s not a philosophical feeling at all. And it’s the feeling that anyone who cares for dualism will surely feel when they hear that Renee Descartes based his whole theory of the unextended mind on the wildly incorrect assumption that electromagnetism did not exist.

Of course, it wasn’t his fault. The West was 200 years away from knowing about electromagnetism. Still, dualism is the metaphysical belief at the heart of modern neuroscience (in practice; people can say whatever they want), and if we take it seriously, Descartes’ confusion matters. Reading The World provides a look at a genius trying to think about the universe without knowing about electricity.

It’s a bit like watching a 4-year old explain how a construction site works without knowing about money. I say this because they’re building some new houses near where my 4 year old and I live in Brooklyn, and last weekend he spent a few minutes explaining what was going on  – why the men were moving and why the men were driving and why the men were shouting, and even lollygagging around. It was an awfully complete vision, and he showed a lot of confidence in it, and I nodded my head and got into it and really learned a lot. But it wasn’t right, because he was missing one huge idea about human motivation. He doesn’t know about money. And if you don’t know about money, you can’t know why construction workers construct, or farmers farm, or shrinks shrink. You just can’t.

Same with Descartes, lacking electricity.  He understands three of the key features of the universe (more or less): matter and light and entropy, which is great. Like any charmingly confident 4-year old, he assumes this is everything, and that he therefore is in position to understand everything. He proceeds to make up some story about why matter moves in circles (he thinks matter moves in circles) and the heavens and the earth, and gives the backstory for the Meditations. It’s a complete theory, and it’s sweet, and it’s poignant, and it’s wrong.

The trouble shows up immediately, just like in that chemistry study section I was talking about.  In the first section he is trying to understand where a fire gets the energy to break a log into its smaller particles – its ash and smoke. He is clearly frustrated in this effort – and this is because he doesn’t know what any high school student knows today: chemical bonds – the things that keep trees together – store electrical energy. When you break these bonds, the energy is released and the various charged particles (to wit, electrons) that have been holding the thing together now (somewhat ironically) push the thing apart, which leads to destruction of the log.

But the place it shows up that is of interest to a dualist comes in his effort to explain why there is no vacuum – or “void’ as he calls it. For if he had known about the electric field not only could he have explained why there is no vacuum more easily (and, in considering the features of a field whose strength is zero, gotten closer to the vacuum-destroying idea at the heart of modern physics, zero point energy). He would almost certainly not have created – as an explanatory overlay – dualism – he wouldn’t have needed to.

Let’s look at it briefly. Following (somewhat) Aristotle’s argument against the void (Physics IV, 8, 215a), Descartes speculates

when a body leaves its place, it always enters into that of another, and the latter into that of still another, and so on down to the last which occupies in the same instant the place left open by the first. Thus, there is no more of a void among them when they are moving than when they are stopped.

Of course this explanation would get nice-try C on any philosophy test today (if that) and a straight F in physics, because (as the philosophers would say) it is forced to falsify its own assumption and therefore (as the physicists would say) is wrong.

Zero in on the phrase “in the same instant.” If Body A leaves a spot “in the same instant” Body B fills it, and the two bodies continue in this manner through all of space and time, ceaselessly going and coming instantaneously, in what sense, pray tell, are they separate bodies? For just a few paragraphs earlier Descartes has written

Note in passing that here, and always hereafter, I take a single part to be everything that is joined together and is not in the act of separation, even though the smallest parts could easily be divided into many other smaller ones. Thus, a grain of sand, a stone, a rock, indeed the whole earth itself, may hereafter be taken as a single part insofar as we are there considering only a completely simple and completely equal motion.

If you think about it, Descartes’ theory here gets rid of time altogether and everything happens instantaneously. He thinks he gets rotating circles from his theory, which he wants to explain the rotating planets, but if you think about it he needs at least one moment of time where a vacated spot is not instantaneously filled with a replacement body to get such circles. Descartes’ theory does not involve any actual movement. Everything is happening en bloc. Which is to say: nothing is happening.

But forget that – it’s not important to our larger goal, which is figuring out why, as the famous T-shirt has it, Descartes Didn’t Know About Electricity And All I Got Was This Lousy Dualism.

You might think it an obvious solution for Descartes to get rid of his annoying “in the same instant” requirement. Why not wait a bit? Slow down, Renee, relax – let the first body leave, and then the second body observe the opening, and then the second body take its place.  Like at a restaurant? Like in duck, duck, goose? Like in musical chairs?

Well the answer is that Descartes, like nature, and like Aristotle, and like (coincidence!) the Catholic Church, abhorred a vacuum. He therefore could not afford to raise the question what is in the space between the time the first body leaves and the body particle enters?  So he avoided it with his self-defeating instantaneity theory.

It’s sad, of course, because had he tolerated the confusion, rather than assuming that to admit spaces between particles was tantamount to positing the existence of a vacuum, he might have proposed an invisible substance that communicates the the news that Body A has moved to Body B.  And, what’s more, communicates not by saying “pssssst, this chair’s empty!” but by imparting a physical desire – a pull – to Body B. Had he done so he would have only cemented farther his grip on modern science. For such a substance – a universal and omnidirectional telephone line – which sends information and motivation with perfect fidelity in all directions – is, albeit in non-mathematical terms, the electric field.

What would have happened had Descartes found himself talking about an invisible, massless, universal entity that can both communicate ideas and move the physical world? Surely he would have asked himself what kind of substance is that?  The struggle to answer this question would surely have altered his Meditations. And had he gone further and put together the remarkable idea that information and physical movement – knowledge and motivation – are one and the same thing, and mediated by an extended (albeit massless) substance distinct from particulate matter, it is plausible he would have lost his appetite for dualism entirely. And who knows? Perhaps he would have even begun to wonder if a massless, extended substance that imparts movement and stores information is tantamount to a mind that wills and wants. And perhaps he would even have proposed the sensible and simple metaphysical (metaphysical! not scientific!) conjecture (conjecture! not theory!) advanced on this website: that matter is matter and the electric field is the mind.