A psychoanalytic exploration of the need to know in western culture. It argues that this need is expressed by the relentless drive of science to get to the source of all phenomena. But the profound reach into the interior of nature is accompanied by primitive unconscious fantasies of mastery, of knowing as making, of masculine intrusion into nature's creativity and of nature's retaliation and deterioration. Science becomes a tool of domination and a suspect magical enterprise. Benign nature becomes an ominous nature. As a result, the need to know becomes a moral quest, in which science unconsciously researches into the internal world of our intentions, externalized into the world of the phenomena that it investigates. The book also argues that the masculine domination of nature is typically understood as phallic mastery and has roots in a fantasy mediated by semen, in which the male identifies with and replicates the sources of life. These themes are addressed in a Kleinian psychoanalytic framework, using clinical, mythological, anthropological and historical material.