In psychoanalysis, another name for an ego instinct, as distinct from a sexual instinct or libido, the prototypical example of a self-preservation instinct being hunger (1). The following key passage occurs in an article entitled ‘The Psycho-Analytic View of Psychogenic Disturbance of Vision’ (1910) by Sigmund Freud (1856–1939): ‘From the point of view of our attempted explanation, a quite specially important part is played by the undeniable opposition between the instincts which subserve sexuality, the attainment of sexual pleasure, and those other instincts, which have as their aim the self-preservation of the individual—the ego instincts. As the poet has said, all the organic instincts that operate in our mind may be classified as “hunger” or “love”’ (Standard Edition, XI, pp. 211–18, at pp. 214–15). Ten years later he began to change his mind on the point made in the last sentence of the quotation—see Thanatos.