This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book attempts to sketch out a 'Psychology of the Person'. The definition of “person” implies that no two people, even identical twins, are the same. Although this is obvious and no sensible person would quarrel with such a view, yet many terms are used that imply that there is a sameness between two or more people. For instance, it is often said that one individual is identified with another, which in ordinary language means that he or she makes him or herself the same as the other, yet this is an impossibility. The relational school has investigated the problem at a practical clinical level but, because the author think the abrogation of the person both within psychoanalysis and within psychology has been so widespread, it is necessary to get to grips with the problem at its core.