To: Howard D.
From: Geoffrey Klempner
Subject: Significance of Philosophical Scepticism
Date: 16 January 2002 10:52

Dear Howard,

Thank you for your e-mail of 30 December, with your essay for Possible World Machine on 'The Significance of Philosophical Scepticism'.

I am invited down to my old school, UCS in London to give a talk to lower sixth formers on 'epistemology' a week from next Friday. This is also the topic of my lectures for the Workers Educational Association on Wednesday evenings. So this will make excellent preparation!

Your essay could also be entitled, 'The Value of Philosophical Scepticism'. The emphasis is very much on how scepticism has helped the progress of human knowledge. But it might also be possible to focus on scepticism as a pathological condition, resulting from philosophical errors/ illusions concerning our relation to the world (as Richard Rorty does in 'Philosophy and the Mirror of Nature' Blackwell 1980) or as a challenge which contemporary philosophers are still required to meet by providing compelling arguments that it is possible to have knowledge of the external world (see Barry Stroud 'The Significance of Philosophical Scepticism' OUP 1984).

Pyrrho was perhaps the first thoroughgoing sceptic (hence the term 'Pyrrhonian scepticism' implying a scepticism that is self-defeating). But he was not the first to raise questions about our right to make knowledge claims. That distinction goes to the Presocratic philosopher Xenophanes:

"No man knows, or ever will know, the truth about the gods and about everything I speak of; for even if one chanced to say the complete truth, yet oneself knows it not; but seeming is wrought over all things."

This was a valuable note of caution at a time when to be a 'philosopher' involved putting forward a 'theory' of the cosmos on the lines of 'Everything is water' or, 'Everything is air'. If you asked why choose one alternative rather than the other, you would be given plausible considerations, but nothing remotely resembling compelling evidence or proof.

I wonder what is the difference between striving to avoid that one 'believes anything at all' and suspending judgement. How do these two attitudes differ? I would have liked to have seen more explanation here.

I am glad that you qualified what you said about the Church: "...therefore there was no need to be sceptical about knowledge. All we could doubt was our understanding." As I was reading the previous paragraphs, I thought of St Augustine's 'Confessions' where the prevailing tone is, "Please forgive me, Father, but I can't seem to understand..."

In your account of Descartes, I didn't like the sentence that begins, "This form of scepticism now often referred to as 'Cartesian Doubt' led him to the realisation that to doubt every single bit of human knowledge was impossible...". The point Descartes is making in the First Meditation is that it is not necessary to doubt each knowledge claim separately, so long as one is able to identify the basic assumptions on which such knowledge claims are based. It is these basic assumptions that the method of systematic doubt is designed to root out. For example, the assumption that we can trust what our senses tell us. How can we do this if, for all we can prove to the contrary, I might be being deceived by an evil demon etc. etc.?

You say, "To really know something implies that we cannot be mistaken, our conclusion is fixed and our result final." The standard response is to say that "If X knows that P, then 'P' is true" is sufficient to account for the thought, "If X knows that P then X cannot be wrong." In other words, if 'P' turns out to have been false, then it wasn't knowledge. We *say* that a person X knows that P only if we believe 'P' is true. But, of course, we can be wrong on both counts! There is room here for arguing that the verb 'to know' has a use (in picking out those persons whose belief that P - which we agree with - have the right sort of grasp on that particular belief) while accepting that no-one can ever defend any claim to knowledge against determined sceptical attack.

You say that the moderate sceptic accepts 'balancing probabilities'. This of course already assumes that we have found an argument to refute scepticism. For the sceptic will say, "It's no good your giving up knowledge claims and settling for probability claims instead, because the same question arises how you *know* that a given probability judgement is true." In the case of Descartes' evil demon, it is no use saying that an evil demon (or evil scientist) is extremely improbable, because your probability judgement already begs the question. Probability judgements, if they are rational, require an evidential basis.

The "extreme alternative to the sceptical mind" is not, as you suggest, believing every proposition and its negation, which would be totally absurd, but rather extreme credulity (as exhibited by young children - and some adults) where one believes what one is told without ever thinking to ask, "How do you know that?"

I enjoyed reading this. Well done.

All the best,

Geoffrey