The cognitive sciences have imparted substantial reality to the unconscious, which psychoanalysis had only been able to access indirectly — through dreams, jokes and diverted actions. Lionel Naccache argues here that Freud was not the great decipherer of the unconscious, is as usually claimed; he was, instead, the most profound theoretician of consciousness — that formidable machine for interpreting unconscious content.

Naccache's scientific research has enabled him to describe with great clarity the processes that give us direct access to the unconscious: blind vision, spatial negligence and the subliminal perception of words and numbers.

In contrast to the current trend which rejects Freudian psychoanalysis, Naccache demonstrates brilliantly why Freud still has much to teach us about how the psyche works.

In the midst of the recent controversies and polemics about psychoanalysis, here is a book on the cognitive sciences that takes Freud's defence. It gives a clear description of those phenomena that give us direct access to the unconscious: the blind vision of patients who put a letter into a letterbox that they have not perceived; the spatial negligence of those who know what is going on in a portion of space that they cannot see; and the subliminal perception of those who, for example, feel thirsty after seeing an ad for a soft drink, without being aware of the ad.

This stimulating book by an eminent member of the young French school of cognitive sciences offers a new theory of consciousness as an “interpreting machine”.

Lionel Naccache is a neurologist working at Hôpital de la Salpêtrière, in Paris. A graduate of the Ecole Normale Supérieure, he holds a doctorate in cognitive neuroscience. He is the author of Le judaïsme à la lumière des neurosciences (2003).