Intentional Self-Deception in a Single Coherent Self

In La Fontaine's well-known fable "The Fox and the Grapes," when the hungry fox first sees the grapes, they look purple, ripe, and sweet; but after he discovers that he cannot reach them, he decides that they are too green to eat. La Fontaine seems to approve of the fox's response, for he suggests that the fox's response is at least an improvement over the alternative of complaining about his bad luck. Elster (1983) refers to the "sour grapes" phenomenon as "adaptive preference formation" (p. 110), but this description seems to me to be potentially misleading. I would reserve the term "adaptive preference formation" for changes in preferences that cannot be attributed to mere changes in belief-for example, the process by which most people acquire a taste for their own national or ethnic cuisine. Although it is not always clear whether a particular response is a case of adaptation of preferences or merely adaptation of beliefs, the story of "The Fox and the Grapes" is as clear a case as one is likely to find of adaptive belief formation. Throughout the story, the fox's preference for ripe, sweet grapes over green, sour ones is stable. What changes is his belief about the ripeness of the grapes he encounters. Why might one think that the fox's change in belief is adaptive; or, alternatively, why would La Fontaine suggest that the fox's response is better than bemoaning his bad luck? The answer seems to be that, though, in the normal case, knowing the truth enhances our ability to satisfy our desires, in many cases, knowing the truth is of little or no use in satisfying our desires, and may actually produce effects-for example, disappointment or even despair-that are very undesirable. In such cases, we can understand why someone-like the fox in the fable-would desire not to know that the grapes are ripe, if they are.