Alasdair MacIntyre argues that Freud's conception of the unconscious is complicated by his tendency to use the term in two different ways. MacIntyre shows how Freud uses the term "unconscious" both as a straightforward description of psychological phenomena, and as an evaluative notion to explain the links between childhood events and adult behavior. This clarification helps to shed light on the many misunderstandings of psychoanalysis, and to separate out what is and what is not of lasting value in Freud's account of the unconscious.

This new edition includes a substantial new preface by the author, in which he discusses repression, determinism, transference, and "practical rationality," and offers a rare comparison of Aristotle and Lacan on the concept of desire. MacIntyre takes the opportunity to reflect both on the reviews and criticisms of the first edition and also on his own philosophical stance.