To: Francis M.
From: Geoffrey Klempner1
Subject: Descartes' dreaming hypothesis in 1st Meditation
Date: 24 March 2004 11:15

Dear Frank,

Thank you for your e-mail of 15 March with your University of London one hour timed essay in response to the question, 'What does Descartes's supposition that he is dreaming contribute to the argument of his First Meditation?'

Being able to hand write clearly at speed is a great advantage. This will stand you in good stead in the exams.

I think an examiner would say that you have answered the question in a way, but you haven't really engaged with it on more than a superficial level. You have chosen the simple strategy of listing Descartes' four arguments, then comparing the dream argument with the other three in terms of what it 'achieves'. The result is that you are led to make some rather prosaic remarks to the effect that the dreaming argument is 'more encompassing than this, less encompassing than that', which in effect merely repeats Descartes' own exposition.

If I was tackling the question I would get right down to the issue of dreaming.

There are two main points, both of which you mention:

(1) I might think I'm sitting by the fire but I might be dreaming it.

(2) Even if I am dreaming, I can make true judgements about general concepts, such as colour, number etc.

What can we deduce from (1)? Here are some suggestions (I am not trying to write a model essay, so you may not want to accept all of these suggestions, or you might think of some more):

- I am currently in mental state X, such that X is consistent with my sitting by a fire, and X is also consistent with my dreaming that I am sitting by a fire.

- Either way, I am capable of making judgements. The only difference is that my judgement, 'I am sitting by the fire' is true in the first case and false in the second.

- More radically, X is consistent with there being no such thing as material objects in space. Here you *can* mention the evil demon, as showing how Descartes understands the dreaming hypothesis. This distinguishes Descartes' use of the dreaming hypothesis from the 'evil scientist' scenario, where matter and space are assumed in setting up the thought experiment.

- Anything else? I'll leave you to think about this. You might come up with something the examiner hasn't thought of!

What can we deduce from (2)?

- So far as the dreaming argument goes, a priori knowledge is still possible. There is room here to give examples which are not in the text, just to show that you have grasped the principle here. For example, colours. If shade A is lighter than shade B and shade B is lighter than shade C then shade A is lighter than shade C. This is something I know a priori about colours. More interestingly, the same area cannot be two different colours.

- The power of judgement is a faculty whose exercise does not require physical conditions or a social context. I know what judgement I am making, regardless of how things are outside my mind at this moment.

- Anything else?

Although I said that you should concentrate on the dreaming argument and avoid giving an exposition of all four, there is scope, in the light of the above, for making the point that the dreaming argument, and the assumptions which it embodies, is in fact the key argument of Meditation 1. Mental state X, and the power of judgement which remains irrespective of whether I am dreaming or not, are the basic building blocks which Descartes uses to construct the evil demon.

There is more. So far, we have merely been concerned with exposition. It is within the remit of this essay to raise objections, to question the assumptions that Descartes has made.

Earlier, I said that 'The power of judgement is a faculty whose exercise does not require physical conditions or a social context.' How plausible do you find this? Can you think of any objections? Judgements are expressed in language, a language which we learned in a physical environment. How would Descartes respond to that point?

And what about that mental state X? How is it defined? It is knowledge of something, but what exactly? I look at my computer screen and see blue. I look at the wall and see grey. While X is in the 'seeing grey' state, what happens to my memory of blue? Isn't it possible that my memory is mistaken? So far as my present mental state is concerned, the situation seems just like the dreaming case. The experience of grey plus the memory of blue is *consistent* with my previous experience being red, not blue.

And so on.

As you see, I haven't mentioned philosophers who have criticized Descartes, or whose arguments can be used in such a critique (e.g. Wittgenstein). That would be within the scope of the essay, but you won't lose marks if you just concentrate on your own exposition and objections.

In your next essay, assume that the examiner is looking for a gripping philosophical argument, and not just testing you on what you know about the text. If you can't see this, then you have picked the wrong question. Answer another one.

All the best,

Geoffrey