Psycho-analysis is a part of the mental science of psychology. […] Psychology, too, is a natural science. What else can it be? But its case is different. Not everyone is bold enough to make judgments about physical matters; but everyone - the philosopher and the man in the street alike - has his opinion on psychological questions and behaves as if he were at least an amateur psychologist. (Freud, 1940[1938], pp. 282-3)

John Forrester always insisted that the scientific character of psychoanalysis be taken seriously - not only as a general ambition and imperative relentlessly reaffirmed by its founder, but also in its manifold peculiar expressions and ramifications. It may suffice to recite the strange class of phenomena listed in the subtitle of The Psychopathology of Everyday Life: ‘forgetting, slips of the tongue, bungled actions,