Question I have a question about Descartes' response in Med. VI to the dreaming argument. It seems to me that his knowledge that he is not dreaming any set of beliefs is based upon the knowledge that his current experiences are consistent with reality, which relies upon the knowledge that he is not dreaming his set of beliefs about reality. Would it be accurate to accuse the response of circularity?

Accepted:
October 16, 2008

Comments

The argument of the Meditations goes as follows: first, Descartes establishes his own existence as a thinking thing; then, purely by considering the content of his thoughts, he establishes the existence of God; then, by reflecting on the nature of God and discovering that He is not a deceiver, he finally establishes the existence of other things. He still concedes that his senses might not reliably show him the way bodies really are, but he feels that he can at least rest assured that they do indeed have properties like size, shape and motion or rest. "They may not all exist in a way that exactly corresponds with my sensory grasp of them, for in many cases the grasp of the senses is very obscure and confused. But at least they possess all the properties which I clearly and distinctly understand, that is, all those which, viewed in general terms, are comprised within the subject-matter of pure mathematics."

Now, there is plenty of scope for criticising this or that step in Descartes' overall argument: but I'm not persuaded that the specific circularity you identify is really a problem. His knowledge that he is not dreaming is based on the nature of God, and his knowledge of that is based in turn on his own internal consciousness. That his current experiences are consistent with reality is the conclusion, and he nowhere appeals to it as a premise. His arguments rest solely on the content of his ideas, and make no presuppositions about whether or not that content corresponds to anything real.

But there is something funny about the end of the sixth Meditation, where he addresses the dreaming argument directly. What he says is this: "the exaggerated doubts of the last few days should be dismissed as laughable. This applies especially to the principal reason for doubt, namely my inability to distinguish between being asleep and being awake. For now I notice that there is a vast difference between the two, in that dreams are never linked by memory with all the other actions of life as waking experiences are." One rather feels that he could have just said that at the start, and saved us all a lot of trouble!

But I think there is a reason why he wasn't in a position to say it until the sixth Meditation. I imagine you're familiar with the more famous 'Cartesian circle', the accusation that Descartes appeals to the veracity of God to validate our clear and distinct perception, but only knew that God existed in the first place because he clearly and distinctly perceived it. He does have a response to that accusation, which he sort of hints at in the Meditations themselves, but brings out more fully in the Replies to Objections. There, he suggests that current clear and distinct perceptions don't actually need any further validation at all, and he specifically identifies God's role as instead being one of validating his memories of past perceptions. So it's not until he establishes God's veracity that he can link his current experiences together with his memories, and thereby distinguish between being asleep and being awake.