ABNORMAL PSYCHOLOGY. By abnormal psycho logy is meant the study of mental processes that deviate from an imagined norm. When the deviation is unmistakable the term "psychopathology" is more commonly employed. Otherwise the terms "medical psychology" or "clinical psychology" are the usual ones, "abnormal psychology" being used only by one psycho pathologist of note—Morton Prince. The term "clinical psycho logy" connotes a special approach and attitude towards the prob lems concerned, one identical with that indicated by the word "clinical" in medicine, namely, that the problem is envisaged as related to the whole of a living organism and not isolated as is often done in academic psychology. It is essential to realize from the outset that this subject is not, as might have been expected, simply the extension of the psychology of the normal to the study of the abnormal. For reasons that will become apparent later, what should have been the applied branch has had to create its own discipline, its own methods and its own general outlook. The case, indeed, has been reversed, for it is becoming plainer that it is only by means of studying the phenomena which for the sake of convenience we call "abnormal"—though they do not possess the attributes commonly associated with this word—that the deeper problems of the mind are at all possible of approach. This holds good for the so-called "normal" as for the so-called "ab normal," so that it is by no means impossible that the uncertainty in nomenclature just alluded to may ultimately be solved by our simply adopting the word "psychology" for the whole field.
The branch of science here considered has been almost en tirely the construction of the past 40 or 5o years. In this time a huge mass of knowledge, little known outside the specialist field, has accumulated. Much of it has been of an unexpected and, indeed, revolutionary nature which requires considerable assim ilation to the generally existing outlook on life and particularly to man's previous view of himself. The difficulties encountered in the earlier advances of science, repeated time and again in the past 400 years, here reach their maximum. They are both ex ternal, in the form of intense opposition to the unwelcome new, and internal, in the form of the subjectivity which is the bane of all science. The presence of the latter difficulty is evident, but an interesting discovery has been made in regard to the former: it appears likely that man's opposition to the new, which is one of his most characteristic qualities, is a radiation into all fields of thought, from the most concrete to the most abstract, of the effects of a deep-seated opposition against self-knowledge.