Psychoanalysis is often credited with giving us a new understanding of memory. For most of us, however, this understanding is less a clear doctrine than a halo of loosely connected ideas, all identified with Freud: memory traces never leave the mind. Painful memories can be put out of consciousness or repressed. Repressed memories, rooted in the traumas and sexual conflicts of early infancy, remain active forces in adulthood, shaping our personalities and returning sometimes to inflict neurotic suffering. Analytic therapy can relieve this suffering by getting to the truth of what was repressed, freeing us to lead happier and more productive lives. These notions are all so familiar that it is easy to lose sight of their strangeness. As Ian Hacking has noted, they reflect an assumption that is ‘dazzling in its implausibility: the idea that what has been forgotten is what forms our character, our personality, our soul’.1 And yet it would be fair to say that these notions or something like them have been elements in an unspoken faith shared by educated Westerners through much of the twentieth century.