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Scepticism: self-refuting or a contribution to knowledge?


To: Kenny S.
From: Geoffrey Klempner
Subject: Scepticism: self-refuting or a contribution to knowledge?
Date: 2 February 2006 10:05

Dear Kenny,

Thank you for your email of 24 January, with your timed essay in response to the University of London Epistemology questions,

'In what sense, if any, might philosophical scepticism be considered a contribution to human knowledge?'

''Scepticism is self-refuting because the sceptic cannot, without contradicting himself, assert that he knows that scepticism is true.' Discuss.'

Before reading your essay (I got as far as the first sentence, 'These two questions are related') I have a general point about answering essay questions.

The questions you will be asked in the examination are specific, not general. They pose a problem in a particular way, sometimes with a particular nuance, and you will lose marks if you not respond to the question, as posed. This is one of the main disadvantages of preparing essays in advance to memorise, which some students do. Always take your time to study the question closely. Ask yourself what the examiner is getting at. Why is the question phrased in that way? Do you agree with the question, as posed? There's nothing wrong with questioning the question, telling the examiner that the question is badly formulated, or makes false assumptions, provided that this is a fair comment on the question AS posed.

You say that the questions are 'related'. Obviously, they are both about scepticism. But on the face of it they are asking quite different things. Anyway, let's see how you have got on.


Despite my reservations, you have made a good case for combining the two questions. The connecting idea here is the notion of a modest scepticism, which does not go so far as to cast doubt on our reliance on our powers of reasoning, but merely points out that the empirical justification for believing things which we previously took to be 'certain' is less than compelling.

Looking at the detail of the argument, this seems OK for things like 'knowledge that there is a table in front of me' or even 'knowledge that I am sitting in the Zephyr Cafe in San Francisco' (I wish). The Matrix scenario makes a pretty convincing argument that you cannot prove that information gained from sense perception is veridical, based only on information gained from sense perception.

So far so good. But then you consider the far more radical idea (as you acknowledge) that memory itself cannot be trusted. If that is the case, then the question is how far does that go. In the previous sentence I used the words 'case', 'question', 'go'. How confident am I that the meanings I now attach to those terms are the meanings I attached to them a moment ago? If that question can be raised, then the very ability to construct arguments and reason are impugned. I no longer 'know' what I am saying or why. A pretty desperate situation I think you'll agree.

That's the thing about scepticism. Once you start on the sceptical path it's difficult to find a sufficient reason to stop. What this thought suggests is that, whereas a detached 'healthy scepticism' might well contribute to human knowledge, determined scepticism is a different case altogether.

But there is another possible take on this. Suppose one could find a dialectical argument refuting 'determined' or strong scepticism. Then that would be a contribution to human knowledge, because it would become a valuable part of philosophical theory.

So the next question is, Does the 'self-refuting' argument do this? You have already argued that the self-refuting argument does not work against modest scepticism. But what about strong scepticism? I don't think it works here either, because (as explained in the Pathways unit which I sent you) the strong sceptic can say: 'Either nothing is knowable or I know just one thing: that the argument for strong scepticism is valid.' The strong sceptic does not have to make a claim. He just gives his argument then shuts up. If you try to say anything, he wags his finger.

Final question: what would be an argument which successfully refuted strong scepticism? I am not going to answer that because that is not what the question asked for. There are clues in the Pathways unit.

I like the clear way you write. There is good evidence here that you are thinking hard about the issues.

One work which I would strongly recommend is 'On Certainty' by Ludwig Wittgenstein. It is the last piece of philosophy he ever wrote and one of his best. Wittgenstein is not hugely popular amongst contemporary analytic philosophers, but if you can get into this it will give you an edge. Barry Stroud's 'The Significance of Philosophical Scepticism' is still probably the best mainstream work on the problem of scepticism. You could also look at Peter Unger's provocatively titled book, 'Ignorance'.

A couple of years ago, I visited my old school in Hampstead, London and gave a talk on philosophical scepticism. There is a brief account of my talk in my first Glass House Philosopher notebook:

You should definitely buy Robert Nozick 'Philosophical Explanations' which contains a seminal treatment of the problem of knowledge. The concept of 'tracking the truth' which you will come across in various writings on this topic is Nozick's. Another book to buy is Thomas Nagel 'The View From Nowhere'.

Why not do some more reading - more challenging this time - and write something on the connection between the problem of scepticism, and the question, 'What is knowledge?' (or, 'Is knowledge justified true belief?'). If you have received your study pack then you can pick an exam question. If not, let me know and I will give you a selection of questions to choose from. Tackle ONE question this time.

All the best,