How does a subject who is competent to detect the irrationality of a belief that p, form her belief against weighty or even conclusive evidence to the contrary? The phenomenon of self-deception threatens a widely shared view of beliefs according to which they do not regularly correspond to emotions and evaluative attitudes. Accordingly, the most popular answer to this question is that the belief formed in self-deception is caused by an intention to form that belief. On this view, the state (...) of self-deception is taken to be a calculated outcome involving a person's intentional manipulation of her own thoughts. I argue that this answer is false and forms an impediment towards making sense of self-deception. I show that, contrary to philosophical prejudice, emotions and desires exert vast and systematic effects on the formation of beliefs. In this, and other, sections of the article, the results of experimental work are brought forward. Self-deception is portrayed here as resembling numerous instances of belief formation which are regularly affected by motivational factors. I argue that self-deceptive beliefs are direct expressions of the subject's wishes, fears and hopes. Qua beliefs which mostly correspond to such factors (rather than to evidence), self-deceptive states are a kind of fantasy. (shrink)