Norman Malcolm wrote:
That something is implausible or Impossible does not go to show that I did not dream it. In a dream I can do the impossible in every sense of the word.
Malcolm nowhere suggests why this remark should be regarded as true. Indeed, many philosophers would regard it is palpably false. After all, it is not at all obvious that one can hope for, intend to do, or believe what is in every sense of the word, impossible. I think, however, that Malcolm's observation is correct; and this paper is devoted to showing why it is correct. In the concluding section I present an account of dreaming that shows why it is that impossible dreams are possible.
“What can a person dream?” This is an odd query; and what it might mean to put this question (if, indeed, it is a sensible question) is not at all transparent. It is not like asking what a person might dream, when this is understood as a request for what someone is likely to dream, or what one may reasonably expect someone to dream, say, on the evening of a day in which one had visited a dentist.