Psyche is an 1846 book by Carl Gustav Carus, a physician and painter noted for his work on animal psychology and physiognomy. In his The Discovery of the Unconscious (1970), Henri Ellenberger calls Psyche "the life-work of a physician and keen observer of the human mind" and "the first attempt to give a complete and objective theory on unconscious psychological life", adding that "It shows the shape reached by the theory of the unconscious at the end of the Romantic period, before the positivistic trend became dominant." He notes that Carus influenced Eduard von Hartmann and later Carl Jung. According to him, Carus defines psychology as "the science of the soul's development from the unconscious to the conscious" and believes that "human life is divided into three periods: (1) A pre-embryonic period in which the individual merely exists as a tiny cell within the mother's ovary. (2) the embryonic period; through fecundation, in which the individual is suddenly wakened from his long sleep, and the formative unconscious develops. (3) After birth, in which the formative unconscious continues to direct the individual's growth and the function of his organs. Consciousness arises gradually, but it always remains under the influence of the unconscious and the individual periodically returns to it in his sleep."