To: Stuart B.
From: Geoffrey Klempner
Subject: Epistemology and the closure principle
Date: 27 March 2007 11:02

Dear Stuart,

Thank you for your email of 13 March, with your University of London Epistemology essay, in response to the question, 'Is knowledge closed under known implication?'

I came back from Prague at the end of last week but it's take a while for me to get back into the working mood. There was a piece on the CSR Conference on the Czech Radio International Service which includes a short except from my presentation:

http://www.radio.cz/en/article/89393

I was certain that I'd sent you an email while I was away, regarding your question about the Early Greek course, but I can't find it. So, apologies if I am repeating myself.

There's no question of 'memorising a whole pile of relatively meaningless fragments'. You learn what the Presocratics said, just as you learn about any other philosophers, and this is the knowledge that you reproduce in the exam together with the views that you have developed on specific issues, so far as these are relevant to the question. It is not necessary to quote directly.

My advice would be to take account of relative frequency of questions, but also give yourself the chance to get 'into' the Presocratics. Heraclitus and Parmenides (I remember writing this last time) are particularly important for understanding the development of Plato's 'two world' theory. Pythagoras was also an important influence. To me, the Presocratics represent a wealth of material to enjoy - certainly, I enjoyed writing the program. (I believe I have sent you the fifteen units - if I haven't, remind me!)

Is knowledge closed under known implication?

This is another very good essay which would do well in an exam. However, I'm puzzled by the issues raised here.

I am sufficiently persuaded by Dretske's example, and others like it, to conclude that there is a serious incoherence in the concept of 'knowledge that', when understood as something that one possesses, or not, in a particular case, at least from an internalist perspective.

I am looking at the zebras in London Zoo. I have no doubt that they are zebras, my knowledge of zoology is sufficient to guarantee that I could not be mistaking them for black and white striped creatures which are not 'zebras' but closely related to zebras. There are no such creatures, and I know this.

When you ask me, 'How do you know that you are not looking and painted mules?', my first response is, 'How absurd! There's no possible way that London Zoo would allow such a thing.' Then you ask me have I heard the News this morning about an impudent hoaxer who has pulled off the most amazing stunts, including substituting painted zebras for mules at New York Zoo. As it happens, I was in a rush and didn't hear the morning News. Now, I have got to make a judgement: who is doing the hoaxing?

David Lewis, in a paper delivered at the Sheffield Department of Philosophy a few years ago (did I tell you about this in a previous email?) grasped the mettle and accepted that there are things we 'know', according to the JTB model of knowledge, until we are asked certain questions, or so long as those questions do not occur to us to ask.

I find this difficult. How can you 'know' something provided that you are not asked certain questions, or that certain questions don't occur to you? How can knowledge be that fragile?

My take on this would be the one I have expressed before, which seems close to the 'performative' view, at least insofar as it locates the concept of knowledge in the area of our interest in identifying persons who may be regarded as having the 'authority' to judge on this or that matter. 'Knowledge' is primarily a third-person concept. The assumption is that P is true, and we are not questioning how we know this or how confident we are in its truth. The question is rather whether to attribute knowledge (which we simply assume ourselves without question) to another subject whose beliefs agree with ours.

Questions of knowledge are not about what I believe but about what you believe. When it comes to myself, the only relevant question is, Is this true?

Such a view is, effectively, externalism although I don't like using this term because I am not a dogmatic externalist. I believe that the explanation in terms of our interest in 'authority' provides a sufficient rationale for understanding the concept of knowledge in this way.

All the best,

Geoffrey