C.G. Jung's archetypes of the collective unconscious have until now remained the property of analytical psychology, and been commonly dismissed as mystical by scientists. But Jung himself described them as biological entities, which have evolved through natural selection, and which, if they exist at all, must be amenable to empirical study. In the work of Bowlby and Lorenz, and in the recent studies of the bilateral brain, Dr Anthony Stevens has discovered the key to opening up this long-ignored scientific approach to the archetype, originally envisaged by Jung himself. Through the cross-fertilisation of disciplines, psychiatry can be integrated with psychology, with ethology and biology. The result is an enriched science of human behaviour.