unconscious. Although thinkers, writers and artists had long recognized the existence of repressed fears and desires, especially in the late nineteenth century when the use of the term 'unconscious' was quite common, the Unconscious was defined as such—as a noun and with a capital letter—by Sigmund Freud. Psychoanalytic theory is based on the foundational distinction conscious/unconscious, or consciousness/the unconscious. Freud considered the discovery of the unconscious to be the third great humiliation that modern science (after Kopernicus and Darwin) had inflicted on the naive vanity of humanity (see: Freud quote). In its broadest sense the term indicates that not all psychic phenomena are reducible to consciousness, but that our psychic life is filled with effective, but unconscious content, which constitutes a distinct system with its own order, mechanisms, and energies. [see: Laplanche/Pontalis quote] Freud's 'discovery' of the unconscious is inseparable from his account of human identity as being founded on repression. For Freudians, primary experiences of identity and subjectivity are constructed around a radical anxiety, summarized as castration anxiety. In his early writings, The Interpretation of Dreams (1900) and papers on the Unconscious in 1912 and 1915, Freud theorised its construction as one of three distinct psychic domains, the others being the pre-conscious and the conscious. He found evidence for its existence in obsessions, symptoms, word association, everyday slips of the tongue and above all dreams. These revealed gaps in conscious life whose missing content psychoanalytic practice showed was disguised or covered over—and thus only indirectly expressed through such mechanisms as condensation and displacement characteristic of dreams. This repressed or censored content of the Unconscious comprised both early memories of the individual and of general humanity originating in primal fantasies or scenes involving forbidden sexual knowledge, the fear of castration or seduction, and, second, instinctual drives or wishes which recognize no constraint and seek only fulfilment. These wishes or drives correspond to what Freud termed 'the primary process' and are censored and brought to a distorted expression, as in dream once more, by a controlling 'secondary process'. The combined operation of these two processes is often seen as analogous to artistic creativity, the implication being that a deep and primary motivation commonly receives oblique and not direct expression. From the 1920s onwards, Freud tended to associate the instinctual drives with the 'id' and saw this as controlled by the agency of the 'super-ego' (the voice of society internalized as a conscience) in the production of the social self or ego. At this time he also theorized the existence in the Unconscious of a death drive.

Freud's 'discovery' was acknowledged and further developed by the French psychoanalyst, Jacques Lacan. Drawing on structuralism Lacan reconceptualized the unconscious in linguistic terms. It was, he wrote, a 'censored chapter' in the history of the subject, traces of which could nevertheless be read in the 'documents' of neurosis, surviving childhood memories, personal vocabulary, traditions, legends and dreams. The unconscious, he declared famously, is 'articulated like a discourse': to be understood as a symbolic system which was only detectable through language and which itself worked through a chain of signifiers and figurative modes. Chief among the latter were metaphor and metonymy which Lacan posited as corresponding to the mechanisms of condensation and displacement associated by Freud with the dream-work. The unconscious comes into being, moreover, at the point of the child's transition into the symbolic order which is the point of the acquisition of language and the acceptance by the child of the symbolic authority of the figure of the father (see: oedipal crisis). These formulations have had a significant influence upon theories of the subject, subjectivity and human identity. They have also alerted readers to the role of unconscious, repressed desires and anxieties and the ways these find distorted or indirect expression in social behaviour and all manner of literary and cultural forms of representation.