To: Matthew M.
From: Geoffrey Klempner
Subject: Existential inquiry into the possibility of knowledge
Date: 27 March 2007

Dear Matthew,

Thank you for your email of 15 March, with your second essay for the Possible World Machine, entitled, 'Essay on the Possibility of Knowledge'.

My initial expectation when I saw this title was that you were going to address the challenge of scepticism, perhaps considering the standard sceptical arguments and then looking at various ways in which one might respond to those arguments.

However, you have understood the investigation into the 'possibility of knowledge' in a somewhat different, but no less valid way as essentially an exercise in phenomenological ontology as conducted by Heidegger, or Sartre. 'When we ask if something is possible, this is to question the Being of the thing questioned.' So, the reader will conclude, when we ask if KNOWLEDGE is possible, this is to question the Being of knowledge.

What is it to question the Being of knowledge? You indicate some initial directions, e.g. in terms of the distinction between immediate knowledge and knowledge which is mediated, the ability to remember what one 'knows', and also the distinction between a priori and experiential knowledge.

However, at least so far as Heidegger is concerned, there is a way to connect such an investigation to the concerns of the traditional sceptic, which results (some would argue) in a far more illuminating response to the sceptic than those traditionally given.

Heidegger's description of 'Dasein' in Being and Time may be seen as a fundamental critique of the Cartesian view of knowledge, where the knower is 'given' pure experience and required to reason its way to an acceptable interpretation of that experience. This is the predicament which the traditional sceptic (as demonstrated in Descartes First Meditation) relies on. From the character of my experience, simply as 'given', there is no way to prove that I am looking out of the window at the trees and houses outside, rather than being directly 'fed' experiences by an evil demon. Experience as such does not carry on its 'face' any indication of its ultimate source. Descartes is reduced to the desperate expedient of attempting to argue for the existence of a God 'who would not be a deceiver'.

In a way not dissimilar to the later Wittgenstein, Heidegger rejects this Cartesian picture as fundamentally incoherent. We are Dasein, situated beings, and any question that one might raise about what we know assumes that we exist in a physical context, practically engaged with the things that surround us - other beings, tools, obstacles and so on.

(For the views of the later Wittgenstein, I would recommend the 'Philosophical Investigations', but also, especially, the very last book that he was working on before he died, 'On Certainty' which is also one of his best. In 'On Certainty', Wittgenstein starts from the famous lecture by G.E. Moore, 'The Refutation of Idealism', where Moore held up his hands and said [something to the effect that] 'This is a hand, and this is a hand, therefore I know that an external world exists.')

There may well be questions that one can raise about the claims of science. Just because a theory is presented systematically or is agreed on by a large number of scientists doesn't mean that it can't be wrong, or that there can't be basic flaws in the way that the scientific enterprise is currently handled. But when it comes to the practical foundations of human knowledge, our situation in the world as agents who use the knowledge we gain in order to negotiate a path through our environment the question of the validity of knowledge cannot be meaningfully raised.

But can't it? Isn't this one of the main themes the Matrix films, that we can APPEAR to be fully involved with a physical environment, when in reality our physical environment is merely a pod which contains our body (or disembodied brain) attached to a virtual reality program. This is not Cartesian scepticism, which raises the possibility that there might be no such thing as 'material objects' or 'space' but rather the a more modest - but no less deadly - scepticism which assumes that there is matter and space but questions whether things might be very different from what we take them to be.

I would love to know what Heidegger or Sartre would say about this challenge. So far as I am aware, neither philosopher has said anything on this topic. My best guess is that the response would be very similar to what philosophers in the analytic tradition have said, that the concept of 'knowledge' has to be grasped in essentially a 'third-person' rather than a 'first-person' way. This is sometimes known as the thesis of 'externalism' (you can look this up).

Well done for completing your second essay. I look forward to receiving your next essay in due course.

All the best,

Geoffrey