Or rather, Derrida, with his ever sharp sense for texts, has a presentiment of this, as he says at one point that, for Descartes, dreaming is more 'natural'; but he moves on swiftly without realising that he has just touched the essential and misrepresented it; Descartes of course does not speak of dreaming as something that is 'natural and universal'; he says that he is a man, and that consequently, it is his custom to dream and to sleep.