After all that phiIosophers have written about self-deception in the last quarter of a century, there is little agreement between them about the right way to analyse it, or even about the meanings of the various analyses that have been proposed. Views range between extremes which are, at least verbally, far removed from one another. Some say that self-deception is an intentional achievement, while others object that it cannot be intentional, because that would not be reconcilable with the concept of belief. The difficulty might seem to be circumvented by the postulation of a separate centre of agency within the self-deceiver, but this suggestion has been criticised both for lack of credibility and, more radically, for incoherence.
The nature of the terrain may have encouraged extremism. It lay to one side of the main track of post-war philosophy of mind, comparatively untrampled and awaiting development. Those who moved into it often underestimated the complexity of the phenomena and offered a single idea which they promoted without much attention to possible alternatives. If their theories caricatured their rivals, they also caricatured themselves.
My contribution to the subject I was not a single explanation for the whole range of the phenomena, but I did develop the idea of the intentional biassing of belief in a form which looked, and may actually have been, exaggerated. This idea would evidently have very little explanatory power if it were not reinforced by the postulation of a rational sub-system, perhaps a separate centre of agency, insulated in some way from the main system which largely controls a person's life. However, my characterisation of sub-systems was too extreme in style, if not in content, and it drew the criticism that such a drastic hypothesis was not really needed in order to explain something so simple and commonplace as self-deception.
Mark Johnston argues in a recent article 2 that the theory that selfdeception is produced by sub-systems operating intentionally is incoherent rather than incredible. So, he looks for another explanation and