Thursday, March 12, 2009

Ockham's Razor and Descartes

Over on the philosopher's magazine blog, an interesting post appeared concerning Descartes Vegetarianism?! According to Bloodless Revolution, a history of vegetarianism by Tristram Stuart, Descartes was a vegetarian. This is very surprising because Descartes is famous for his view of animals as mere machines.

From the Internet Encyclopedia of Philosophy:

One of the clearest and most forceful denials of animal consciousness is developed by Rene Descartes (1596-1650), who argues that animals are automata that might act as if they are conscious, but really are not so (Regan and Singer, 1989: 13-19). Writing during the time when a mechanistic view of the natural world was replacing the Aristotelian conception, Descartes believed that all of animal behavior could be explained in purely mechanistic terms, and that no reference to conscious episodes was required for such an explanation. Relying on the principle of parsimony in scientific explanation (commonly referred to as Occam's Razor) Descartes preferred to explain animal behavior by relying on the simplest possible explanation of their behavior. Since it is possible to explain animal behavior without reference to inner episodes of awareness, doing so is simpler than relying on the assumption that animals are conscious, and is therefore the preferred explanation.

To be fair, Descartes was a vegetarian for mostly health, not ethical, reasons. However, Stuart suggests that Descartes was disturbed by the problems surrounding sentience. If animals did feel pain, then it would be wrong to kill them for food (see Singer: Animal Liberation 1975).

An easy way around this puzzle is to simply assume that animals are not conscious, feeling no pain. Moreover, this is the simplest argument. However, as Todd pointed out in his post, the simplest argument is not always the right argument. Animal consciousness is a hotly debated topic in animal ethics (see the Stanford Encyclopedia of Ethics entry on Animal Consciousness for a primer). Ockham's razor, much like faith, shouldn't be used as a cognitive default to prevent us from exploring the complexity of the world around us.



Hanno said...

Steve did not suggest that Ockham's razor is the only test for theory preference.

Josh said...

True, Steve did not suggest that Ockham's razor be the only test for theory preference. I wished to simply underscore Todd's point concerning the limits of Ockham's razor. Simplicity is as alluring as the song of the Sirens.

Also, I thought it was weird that Descartes was a vegetarian!?

Hanno said...

i havent read Stuarts piece, but his analysis seems highly unlikely. The view that animals are just machines predates Descartes, and it extremely widespread throughout Europe all the way into the 1800's. This view as some sort of psychological defense mechanism seems unlikely. Rather, he simply accepts the widely held view.

Josh said...

For a philosopher that wanted to uncover the fundamental truths about life by starting from scratch (i.e. discarding all of his former beliefs), it is more than curious that he merely adopted the prevailing theory of the time.

Steve Gimbel said...

I don't see why you say that the simplest argument does not attribute sentience. The argument for sentience runs something like this:

(1) Dogs have nervous systems that look a lot like ours.

(2) Dogs react to stimuli that would cause pain for a human in ways that mirror a human in pain.

Therefore, dogs experience pain similar to the way humans do.

The argument for dogs as automata distinguishes between a brain and a soul, attributes the ability to feel pain to the soul, contends that humans have souls and dogs don't, and explains that the reactions that seem like pain in dogs really are just reflexes. Seems like a whole lot of metaphysical baggage just to make sure only humans are judged and allowed into heaven since we were created in the image of a further ontological commitment.

It seems like the normal version of Ockham's razor here gives us reason to think dogs do feel pain.

The version I was referring to, though, is only operative as a criterion of theory choice when you have two theories that are completely empirically equivalent. It's not clear that this is the case here. If we were clever enough, it seems like we should be able to come up with some crucial experiment where automaton dogs would act one way and sentient dogs would act another. Perhaps we should watch Sleeper for ideas...

Man, are we gonna have lots to talk about when I come down in a few weeks.

Josh said...

Let's leave Woody Allen out of this ;0

The sentience argument is simple and compelling (by the way, Singer was on the Colbert Report last night...weird).

However, Descartes didn't buy the similarity argument. He would say that parrots can pronounce words as well as we can, and nevertheless cannot speak as we do. He applies the same argument to pain. Animals may mirror our pain, but do not experience it in the same way.

To Descartes this was the simpler argument, because he could ignore the complexity of consciousness.

This argument is also a twofer:

1.) It fits with a prevailing mechanistic view of the world (as Hanno pointed out - but that shouldn't really matter to a man who wants to doubt everything)

2.) It also functions as a psychological defense for those who wish to eat meat. (even though he himself was a vegetarian)

In a letter to More Descartes wrote, "Thus my opinion is not so much cruel to animals as it is indulgent to human beings since it absolves them from the suspicion of crime when they kill or eat animals"

To answer the inevitable Furman dictum of "So What?"

Descartes was a weird dude.

Hanno said...

Ockham's razor surely comes in with a metaphysical addition of a soul, thought by Descartes to be necessary for sentience. That is why for D., Ockham's razor shaves to soul away from animals. Jettison that, as Steve just did, and the argument looks far worse.

Steve Gimbel said...

I always think that the key to reading Descartes is to remember that he is trying very hard to combine his Catholicism with the results of the new scientific revolution that he is a driving factor in. On the one side of him are those who demonize Galileo and Copernicus and on the other side are radical skeptics and classical Stoics (Hanno pointed this out to me years ago and I think he is dead on), and he's trying to carve out a middle path. His argument does seem weird to us, but makes more sense if you think of it as an attempt to find a way that marries a mechanistic picture of the material world (what he sees emerging from the new ability to mathematize physics -- something that was not possible prior to his work on analytic geometry [astronomy could be mathematized, but not physics]) with the existence of the spiritual which was needed for religious reasons. He's trying to be a religious scientist.

Interesting note that I found in researching Descartes. At the time, hydraulic statues had just been introduced in Paris. The statues used water pressure to move limbs, rotate torsos, and play music calliope-style. So, we have something that looks like the earliest form of robots and this had to blow people's minds. Bodies could be thought of like these moving, sound generating statues.