Abstract
In the nineteenth century, leading psychologists and philosophers split on the issue of the existence of the unconscious. Sigmund Freud developed his ideas about the unconscious in many of his works, but two in particular were devoted to this topic: a brief paper, “A Note on the Unconscious in Psychoanalysis” and a longer paper “The Unconscious”. Freud’s appeal to hypnotic states to prove unconscious mentality has been criticized by many commentators including some sympathetic to many of his theoretical views. Freud distinguishes three senses of the expression “the unconscious”: the descriptive, the dynamic, and the systems sense. Freud often speaks of unconscious ideas, but the German word he uses for “idea” applies not only to what in English is termed an idea, but also to images and presentations. According to some of Freud’s supporters, his distinctive contribution was his development of the theory of the dynamic unconscious.