In Part I, I consider the normal contexts of assertions of belief and declarations of intentions, arguing that many action-guiding beliefs are accepted uncritically and even pre-consciously. I analyze the function of avowals as expressions of attempts at self-transformation. It is because assertions of beliefs are used to perform a wide range of speech acts besides that of speaking the truth, and because there is a large area of indeterminacy in such assertions, that self-deception is possible. In Part II, I (...) analyze the conditions of self-deception, and discuss the grounds on which it is regarded as irrational, even when particular instances may be beneficial. I consider some of the classical analyses of the motives for self-deception, and attempt to give an account of the occasions in which it is likely to occur. In the final section, I discuss the complex organization of the self that is presupposed by the phenomena of self-deception. (shrink)