On the function of self-deception

Self-deception makes best sense as a self-defensive mechanism by which the self protects itself from painful reality. Hence, we typically imagine self-deceivers as people who cause themselves to believe as true what they want to be true. Some self-deceivers, however, end up believing what they do not want to be true. Their behaviour can be explained on the hypothesis that the function of this behaviour is protecting the agent's perceived focal benefit at the cost of inflicting short-term harm, which is a basis for a unified account of the phenomenon. In this paper, I argue that this view is narrow. Cases of altruistic, benevolent, and even self-punishing self-deception also exist. There, the function is not the self-deceiver's benefit. In fact, self-deception may have no function at all. Therefore, I put forward a novel account that analyses the function of self-deception on a case-by-case basis.