Re: Descartes and the Mind

From: Harnad, Stevan (harnad@cogsci.soton.ac.uk)
Date: Fri Oct 20 1995 - 19:54:06 BST


> From: "Harrison, Richard" <RJH93PY@psy.soton.ac.uk>
> Date: Fri, 20 Oct 1995 12:03:53 GMT
>
> although laws such as the law of gravity are not necessarily going to
> apply tomorrow (or whenever) we can be confident enough to make it
> worth studying.

"Confident enough" was not the issue with Descartes, certainty was.

> The same is true of 'other minds'. However, I realise
> this is not the point of this debate which suggests there is something
> irredeemably different about 'mindstuff' as opposed to matter.

That's right. Of course you all exist. But it's important to remember
that that is an inference about which I can be confident, but not
certain, whereas the truths of mathematics and the reality of
experience are things about which I can be certain: They are not just
extremely likely. (And that difference is not merely one of degree:
Even a person who lives extremely long is not immortal, and even a very
long trip is not endless, etc.)

And it's a surprising fact (isn't it?), that "mindstuff," of all
things, should turn out to be the one on the certain side of the
ledger, with all of matter on the other...

> OK, but the Cogito doesn't seem to imply that doubting (or experience)
> is different [from] all the doubtable phenomen[a]; merely that we
> cannot be sure it isn't. Is it not a little self-centred of humans to
> consider themselves to be different from everything else in the
> universe.

You're right that not-certain does not mean not-true. But, on the face
of it, the fact that, in the universe, there seem to be only two kinds
of examples of certainty -- the eternal truths of mathematics and the
existence of experience -- does seem to make things look a bit
animocentric, doesn't it?

> our experience of the hurting tooth could be the same if we were
> a 'brain in a vat' with sensory input being controlled by some
> outside means. All we have to go on is our past experience,
> which we have already discarded as open to doubt. There doesn't appear
> to be a way of bringing everything else back without introducing
> doubt. Maybe the only way to continue (from our position in the
> 17th century...) is to accept the probable as our area of study and
> leave the doubting and metaphysics to the philosophers. Richard

We will, but let's first be sure we learn its lessons.

Stevan



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