2011 reprint of 1927 first English Edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. The Ego and the Id is a foundation document in psychoanalysis first written by Freud in 1923. It is an analytical study of the human psyche outlining his theories of the psycho-dynamics of the id, ego, and super-ego, which is of fundamental importance in the development of psychoanalytic theory. The study was conducted over years of meticulous research and was first published in English in 1927.