Adam asked:

I read that there are two ways of trying to deal with skepticism - to prove it false or to refute the
reasoning leading to it. What would be examples of each and which is the best strategy for dealing
with skeptical arguments?

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The situation is a little more complicated than that.

One kind of sceptical move considers the class of statements which are taken to provide evidence for
a claim, and argues that no statement from that class or set of statements, however large, is capable
of supporting that claim. An example would be the claim that there exists a world of objects outside
us, which is taken to be supported by the evidence of our senses. In his first Meditation,Descartes
argues that it is consistent with all the experiences I have enjoyed up to the present moment in time,
that there is no world of objects outside me, and that I am merely being fooled by an Evil Demon into
thinking that an external world exists.

Another, more subtle, kind of sceptical move takes the kinds of everyday things we take ourselves to
know and points out that we would withdraw our claim to knowledge if we were asked questions that
we had not previously considered. For example, I would declare without hesitation that I know that
Tony Blair is Prime Minister of England. But if I were asked, 'Do you know that Tony Blair has not
resigned in the last hour?' I would have to answer, No. I haven't been listening to the News, so
obviously I cannot say whether, during the last hour, he has resigned or not. In that case, I cannot say
that I knowthat Tony Blair is Prime Minister. If we try to restrict our knowledge claims to take account
of such questions, we find that we are able to claim less and less. If I don't' know everything— if I
can't rule out the various possibilities that would undermine the knowledge claims that I would
normally make, then I don't, in fact, know anything.

Descartes solution to scepticism with regard to an external world — the first kind of scepticism — was
famously to argue for the existence of a God who is not a deceiver. That is your first alternative: a
proof that scepticism with regard to an external world is false. It is false because I do know that an
external world exists. I know this because I can prove that God exists, a God would not allow me to
be deceived into believing in the existence of an external world, if there did not in fact exist an
external world.

Your alternative, of 'refuting the reasoning that leads to scepticism' splits up into two different
strategies. If we stick with the external world, one strategy would be to argue dialectically that if we
did not have knowledge of an external world, in which we were one object — one conscious subject
— amongst others, then we could not have knowledge of our own experiences. This is the basic
structure of Kant's 'Refutation of Idealism' and also Wittgenstein's argument against a 'private
language'. (Following Kant, these are sometimes called 'transcendental arguments'.) However, it is
always open to the sceptic to accept the suicidal conclusion that I don't have any knowledge evenof
my own experiences, or of my own existence as a subject of experience.

The second strategy would be the kind of move that Berkeley makes with regard to belief in an
external world. It is this kind of move that Kripke in Wittgenstein on Rules and Private Languagecalls
a 'sceptical solution to a sceptical challenge.' (Kripke gives the example of Hume on causation.)
Berkeley effectively concedes Descartes' Evil Demon hypothesis, but argues that all we can possibly
meanwhen we make statements about objects in the world is that we have certain kinds of
experiences. There is nothing to be sceptical about.— However, agreeing with the sceptic is a pretty
desperate strategy.

Which of the three alternatives is the best way to resist scepticism concerning an external world?
Take your pick.

It is what I called the 'second, more subtle sceptical move' that makes us begin to realize how elastic
is our concept of knowledge. Sometimes it seems right to say you know, or that she knows, and
sometimes it doesn't. Cases shade into one another. Sometimes, you kind-of know. It is because the
concept of knowledge is so difficult to pin down, so elastic, that 'the problem of scepticism' figures
quite low down on the list of major philosophical problems, and also why it is so hard to get students
to take it seriously.

Geoffrey Klempner