Hume maintained that “since all actions and sensations of the mind are known to us by consciousness, they must necessarily appear in every particular what they are, and be what they appear.” Descartes maintained a very similar doctrine, and Locke and Berkeley held at least part of the doctrine. I shall not try to set out precisely what any of these philosophers thought about self-knowledge; I cite them simply as proponents of the general view which I shall be examining in (...) this paper: namely, that each of us has a special epistemic authority about his own mental life. This view is still widely held, particularly in the form of the thesis that one's sincere avowals of current mental states are incorrigible, i.e., such that, necessarily, no one ever has overriding reason to think them false. (shrink)