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October 20, 2006

Consciousness: Descartes' Error

The philosopher John Searle wades, with some confidence, through the swamp of attempts to make sense out of the forum in which we attempt to make sense: consciousness. Some of the issues in question are technical: "perception" versus "sensation," for example. But one of his points echoes one of the more significant moments in the history of disbelief: Descartes cogito ergo sum -- "I think therefore I exist."

Here's Searle saying "my consciousness exists":

Consciousness is real and ineliminable. It cannot be dismissed as some kind of an illusion, or reduced to some other phenomenon. Why not? It cannot be shown to be an illusion because if I consciously have the illusion that I am conscious, I already am conscious.

Descartes reaches this moment at the end of a brave effort to confront skepticism at its most scathing. Is there anything we could know, could believe in, even if some evil god were purposely trying to deceive us? This is not Searle's issue, at least in this article. But it is a very important issue in this history. For skepticism of this intensity, as Descartes understood, certainly includes among its targets the belief in a just God.

The place where Descartes manages to take a stand against skepticism is, as Searle is acknowledging, a reasonable one, though some would fiddle with the tense or a couple of the words. The problem comes when Descartes tries to move on from there. Having proven that there is something that we -- or more properly he -- could know, he makes a move that seems as clumsy as his original point was brilliant (unless it was somehow, shockingly tongue-in-cheek). Descartes concludes that since something he thought was true -- his own existence -- proves to be true, the rest of what he thought to be true must be true. Here's what he writes:

Accordingly it seems to me that already I can establish as a general rule that all things which I perceive very clearly and very distinctly are true.

Among those things that are, therefore, true, according to this odd reasoning, is, of course, God -- the precise Christian God that Descartes apparently perceived "clearly" and "distinctly."

Posted by Mitchell Stephens at October 20, 2006 2:33 PM


A philosopher interprets a psychologist.
If you dig deeper into Searle's work you find he believes we (humans) will eventually understand the science of the brain-mind. I disagree.

I think we will discover how to make changes in the brain before we understand how it works; changes that will drastically change the mind and how we interact. What those new beings will think about and do is beyond our awareness horizon.

I love this stuff. You have applied it to the God question; these guys seldom bother with that.

As to the patients that Searle talks about who can have some awareness of things they cannot "see", there ARE two pathways for visual perception and I am surprised Searle does not mention (or know) about this.

Vilayanur Ramachandran is the Man when it comes to the study of cognitive and perceptual deficits in human neurological patients. He explained the phenomenon that bothers Searle quite eloquently for anyone who has a TV that gets PBS.

Posted by: Jay Saul at October 20, 2006 6:41 PM

Descartes' error indeed.

Your exposition of Descartes' absurd "established general rule" is appreciated.

Posted by: Peter Rock at October 21, 2006 6:08 AM

"Accordingly it seems to me that already I can establish as a general rule that all things which I perceive very clearly and very distinctly are true."

But don't we all really do that? We may intellectually discuss truth and reality but how could we even get out of bed without pre-consciously believing our perceptions are real?

I think the Nicholas Humphreys, the author of the book Searle is reviewing, makes some very powerful and interesting arguments about the difference between sensation and perception.
I believe the space between those two is THE mystery of life.

Posted by: Jay Saul at October 22, 2006 11:31 AM

Jay says:

"how could we even get out of bed without pre-consciously believing our perceptions are real"

By getting out of bed and not believing our perceptions are real.

Posted by: Peter Rock at October 23, 2006 5:47 AM

If you really want to know that you exist, and that you are real, then stick a nail into the palm of your Hand, through the bone part as well and out through the knuckle to intensify the pain, and then tell me you don't exist. that this life is all an illusion and that the world is all in your head?
this argument will be over in two seconds flat when you do the nail trick, because of the intense pain you will suffer weeks after wards, while still contemplating this topic.

Posted by: Nigel at July 16, 2009 12:26 AM

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