People do, quite naturally and not uncommonly, speak of other people as deceiving themselves, as being their own dupes. A man's child is ill and growing constantly worse. The father keeps talking optimistically about the future, keeps explaining away the evidence, and keeps pointing to what he insists are signs of improvement. We can easily imagine ourselves deciding that he has deceived himself about his son's condition. Nor is it the case that talk of self-deception is appropriate only in connection (...) with other people. We can easily imagine the father admitting, say, after the son's death, that he has deceived himself about the child's condition. Thus the notion of self-deception obviously has application. Furthermore, ordinarily talk of self-deception is not thought to be puzzling. (shrink)