 Finally, a common objection has it that the universality of doubt undermines the method of doubt itself, since, for example, the sceptical hypotheses themselves are dubious. Descartes thinks this misses the point of the method: namely, to extend doubt universally to candidates for knowledge, but not also to the very tools for founding knowledge. As he concedes: “there may be reasons which are strong enough to compel us to doubt, even though these reasons are themselves doubtful, and hence are not to be retained later on” (Replies 7, AT 7:473f, CSM 2:319).