(das Es) The part of psychical apparatus where the instinct are located in Freud, Sigmund’s topography. Freud himself did not use the term ‘id’; it was introduced by his English translator James Strachey, who also used Latin terms for the other two key constituents of the psychical apparatus, namely the ego and superego. Freud borrowed the concept of the id from German psychiatrist Georg Groddek who, in turn, most likely adapted the idea from Nietzsche, Friedrich’s opposition between the ‘I’ and the ‘it’ in Beyond Good and Evil (1886). The id is a reservoir of energy that the other parts of the psychical apparatus draw on, but must also contain if they are not to be overwhelmed by it. The id does not understand ‘no’; it is the pleasure principle unconstrained by the reality principle.