# The Psychology of Insanity/Preface

PREFACE
This book lays no claim to be a comprehensive treatise upon the psychology of insanity. The number of independent schools of thought oxisting at the present day, and the fundamental divergence in their methods of investigation, make it obviously impossible to compress such a treatise into the limits of a small volume. All that has been attempted here is the presentation of certain recent developments in abnormal psychology which have already yielded resulta of fundamental importance, and which seem to offer an exceptionally promising field for further investigation.
An endeavour has been made to develop the subject-matter of the book in a systematic manner, so that the general principles which it is sought to establish may appear in as clear a light as possible. The adoption of the systematic method in a work of this size, however, renders a somewhat dogmatic mode of presentation inevitable. It is necessary, therefore, to warn the reader that many of the theories to which he will be introduced have not as yet been firmly established, and that they are to be regarded rather as suggestive hypotheses which ​will ultimately require considerable alteration and improvement.
It must be clearly understood, moreover, that no attempt has been made to cover the whole field of insanity. On the contrary, certain sections of that field have been more or less arbitrarily selected, mainly on the ground that they yield fruitful results to psychological methods of investigation. I confidently anticipate that in the future these methods will have a far wider application, but in the present state of our knowledge it must be frankly admitted that there are whole tracts of insanity in which they have only a very limited utility. This confession is all the more necessary on account of the tendency to unduly extensive generalisation evident in the work of many recent investigators. In view of the enormous complexity of mental processes, and the youthfulness of psychology, it is best to realise that progress must inevitably be slow, and that we must be content to feel our way to the scientific laws of the future.
A very large number of the general principles enunciated in this book are due to the genius of Prof. Freud of Vienna, probably the most original and fertile thinker who has yet entered the field of abnormal psychology. Although, however, I cannot easily express the extent to which I am indebted to him, I am by no means prepared to embrace ​the whole of the vast body of doctrines which Freud and his followers have now laid down. Much of this is in my opinion unproven, and erected upon an unsubstantial foundation. On the other hand, many of Freud’s fundamental principles are becoming more and more widely accepted, and the evidence in their favour is rapidly increasing. In the present volume I have endeavoured to introduce only those principles which have already acquired a satisfactory claim to recognition.
Among many other authorities to whose writings I have had recourse, Dr Jung of Zürich, Prof. Janet of Paris, Prof. Karl Pearson, and the late Prof. Krafft-Ebing must be specially mentioned. Lastly, I am very greatly indebted to Mr W. Trotter’s two papers on “Herd Instinct,” published in the Sociological Review for 1908 and 1909.
I have to thank Dr Edward Mapother for much valuable assistance in the preparation of the manuscript and the revising of the proofs.
Bernard Hart
PREFACE TO SECOND EDITION
In the preparation of the second edition comparatively few alterations have been made in the text. The bibliography, however, has been revised and enlarged, and reference has been made to works in which the general principles described in this book may be followed into wider fields.
Bernard Hart
PREFACE TO THIRD EDITION
Although nearly four years have now elapsed since the publication of this book, no substantial alterations have been made in the preparation of the present edition. This is not because psychology and psychiatry have made no progress, but because the book is concerned solely with elementary principles, and recent advances have been rather in the superstructure built upon these principles than in the principles themselves.
Something must be said, however, of the rich material offered to the psychologist by the great events of the past two years. The power of emotion in the direction of human thought, the impotence of logic to affect the conclusions dictated by passion and prejudice, and the extent to which man’s mind is controlled by psychological processes of which he is himself entirely unconscious, have been so abundantly demonstrated as to become obvious to the most superficial observer. The description and explanation of these conceptions form an integral part of this book, and, were it now making its first appearance, it would unquestionably have been illustrated with copious examples from ​recent history. It has been considered more profitable, however, to retain the examples originally selected, and to leave as a valuable exercise for the reader the application of the principles described to the psychological material of the present time.
Bernard Hart
May 1916