Psychoanalysis is a system of thinking inserted into a particular historical niche. Simply speaking the problem that Freud met in his patients was the repression of their sexual desires. It was a problem in those patients of his but also this problem characterised that particular era in western Europe and the New World. Sex was something dirty; men were superior to women; homosexuality was a perversion and in most societies a criminal act. So sexual desires had to be suppressed and Freud had the view that a condemned sexual desire found expression in a piece of behaviour which was neurotic. Neurosis was the product of a dammed up sexual impulse that was forced to find expression in a different mode. Freud’s later theory is where he sees mental illness as being the manifestation of parts of the personality which are dissociated from the centre and therefore not coherent.