Descartes's Dream Argument

Descartes’s Dream Argument

This would all be well and good, were I not a man who is accustomed to sleeping at night, and to experiencing in my dreams the very same things, or now and then even less plausible ones, as these insane people do when they are awake. How often does my evening slumber persuade me of such ordinary things as these: that I am here, clothed in my dressing gown, seated next to the fireplace – when in fact I am lying undressed in bed! But right now my eyes are certainly wide awake when I gaze upon this sheet of paper. This head which I am shaking is not heavy with sleep. I extend this hand consciously and deliberately, and I feel it. Such things would not be so distinct for someone who is asleep. As if I did not recall
He says, “I remind myself that on many occasions I have in sleep been deceived by similar illusions,” so he seems to be relying on some knowledge to the effect that he has actually dreamt in the past and that he remembers having been “deceived” by those dreams. That is more than he actually needs for his reflections about knowledge to have the force he thinks they have. He does not need to support his judgement that he has actually dreamt in the past. The only thought he needs is that is now possible for him to be dreaming that he is sitting by the fire, and that if that possibility were realized he would not know that he is sitting by the fire. Of course it was no doubt true that Descartes had dreamt in the past and that his knowledge that he had done so was partly what he was going on in acknowledging the possibility of his dreaming on this particular occasion. But neither the fact of past dreams nor knowledge of their actual occurrence would seem to be strictly required in order to grant what Descartes relies on – the possibility of dreaming, and the absence of knowledge if that possibility were realized. (p. 17)

-Yes: E.M. Curley (Descartes Against the Skeptics): Step in Curley’s reconstruction of Descartes’ argument:

(2) Sometimes I have, in dreams, experiences which I take to be of ordinary-sized
-No: J.L. Austin (Sense and Sensibilia):

Another erroneous principle which the argument here seems to rely on is this: that it must be the case that “delusive and veridical experiences” are not (as such) “qualitatively” or “intrinsically” distinguishable – for if they were distinguishable, we should never be “deluded”. But of course, this is not so. From the fact that I am sometimes “deluded”, mistaken, taken in through failing to distinguish A from B, it does not follow that A and B must be indistinguishable. Perhaps I should have noticed the difference if I had been more careful or attentive…” (p. 51)

I may have the experience … of dreaming that I am being presented to the Pope. Could it be seriously suggested that having this dream is “qualitatively indistinguishable” from actually being presented to the Pope? Quite obviously not. After all, we have the phrase “a dream-like quality”; some waking experiences are said to have this dream-like quality, and some artists and writers occasionally try to impart it, usually with scant success, to their works. But of course, if the fact here alleged were a fact, the phrase would be perfectly meaningless, because applicable to everything. (p.