"The Deceived Belief Must Be Genuine" (more from Greg Bahnsen's doctoral dissertation)

We have maintained that deceived people believe false propositions, and we have elaborated a basic characterization of belief. It will turn out on the analysis being developed here that self-deception actually involves two beliefs which are in conflict. This will be defended in chapter 4. What can be observed here, however, is that the conflict that exists within the self-deceiver can be adequately described as a conflict between two beliefs, and need not be portrayed as a conflict between knowledge and belief. That is, rather than saying that the self-deceiver knows one thing and believes contrary to it, it will be sufficient simply to say that the self-deceiver believes something and yet believes something contrary to it. The contrary belief in either case will be false. However, there is no need to maintain that the other belief to which it is contrary is true and held on good evidence; that is, there is no need to say that it is knowledge (a true belief held on good evidence) to which the false belief is contrary in self-deception. What the self-deceiver takes to be true (i.e., believes) need not actually be true. What is at issue is not whether the self-deceiver holds a false belief in conflict with a true one. It is equally appropriate in self-deception that the conflict be between a false belief and another false belief, for it is the conflict-state that constitutes the condition for self-deception. As long as the self-deceiver actually believes a proposition to be true, it can be objectively false and still serve to set up or generate a conflicting (and similarly false) belief. Our analysis of self-deception need not become complicated, then, with a mixture of knowledge and belief. A person can deceive himself about a belief which he holds whether or not that belief actually has good supporting reasons and turns out to be true or not. Those are extraneous matters here. The important thing is that the self-deceiver believe some proposition and then (falsely) believe something which is incompatible with it.1

1.  Greg L. Bahnsen, A Conditional Resolution of the Apparent Paradox of Self-Deception (USC Doctoral Dissertation [Philosophy], June 1978), p. 147-8. Underlines for emphasis are original.