Id is the Latin word for it. The word is used in psychoanalytic theory to denote a broad, impersonal realm of the soul beneath the ego (I) and the superego (Superego).
Id is the locus of our impulses and the source of libido.
Karl Marx and Sigmund Freud had a profound influence on the semioticians, especially in Europe. Terms borrowed from Marxist discourse constitute one important part of the fabric of semiotic writings, and those from Freudian discourse another.
One of the most important terms in Freudian psychoanalysis is, of course, Id.
