Psychological identity. Conceptual computer artwork of a headless person and two psychology books. One of the most fundamental psychological and philosophical concepts is that of the self, a feeling that you exist independently from others and have your own experience of the world around you. The psychologist Sigmund Freud (1856-1939) divided the self into three parts: the Id, Ego and Superego. The Id is an unconscious sense of self, while the Ego is the conscious sense of the self. The Superego is an unconscious morality. One of the most well-known theories of the Ego is that of Carl Gustav Jung (1875-1961).