ABSTRACT
THERE is, prima facie 9 a simple but devastating objection to the use of the coherence principle for finding out whether one is awake or dreaming, and it is surprising that either it has not occurred to the philosophers who accept the principle or, if it has, that they have said nothing about how to deal with it. Making use of the principle consists in noting whether certain ‘phenomena’ presented to one are connected in the right ways with other phenomena, past, present and future. The objection that should occur to any-one is that it is possible a person should dream that the right connections hold, dream that he connects his present perceptions with ‘the whole course of his life’. The coherence principle tells us that we are awake if we can make these connections and asleep in a dream if we cannot: but how does the principle tell us whether we are noting and making connections or dreaming that we are? It seems to me that obviously it cannot and therefore the principle is worthless. I suspect that the principle has been accepted without any very serious consideration of its operation because philosophers have assumed that it must be possible to tell whether one is awake or asleep (at least with probability) and also it has seemed to them that there could not be a test for this other than coherence. 109Without thinking it through they have supposed that coherence works as a test, because it has to work.
