Recent theories of critical thinking have stressed the importance of taking into consideration in critical enquiry the perspectives, or presuppositions, of both the speaker whose statements are under scrutiny and the critic himself. The purpose of the paper is to explore this idea from an epistemological (rather than a pedagogical or psychological) point of view. The problem is first placed within the general context of critical thinking theory. Three types of perspective-dependence are then described, and the consequences of each for the possibility of critical discussion discussed. It is concluded that although it is essential in critical discussion to take the other’s perspective into consideration, perspective-dependence does not exclude the possibility of criticism