Personal construct psychology takes the person to be the irreducible unit. Traditional psychology is not, in the main, about persons. By making the person the central subject-matter of psychology, construct theory changes the boundaries and the content of the existing science. The philosophical assumption of the psychology of personal constructs is explicit and they include an acceptance of a reality ‘out there’. Psychologists have avoided studying us as persons by studying ‘us the animal’. Psychologists have followed custom in establishing social psychology as a mini-psychology in its own right and have thereby hindered the development of a general psychology of persons. The study of personality would seem to be inescapably the study of the person and yet again, by demoting it to an area within psychology, the equivalence of the terms ‘psychological’ and ‘personal’ has been lost. The attempt to encompass the person within the study of personality is additionally bedevilled by the persistence of trait psychology.