抄録
It is thought that the problem of self-deception is difficult to treat because it includes a paradox. I investigate under what conditions self-deception occurs, rather than how the paradox is solved. I think one of the important conditions of selfdeception is that the two apparently contradicting beliefs coexist without either of them being unconscious. After surveying the discussions concerning whether self-deception is intentional, I focus on the role of "motivation", following Alfred Mele, and try to state the necessary and sufficient conditions of self-deception on the basis of the motivations and situa-tions of the self-deceivers.
