Page:Mind (New Series) Volume 12.djvu/421

 NEW BOOKS. 407 In the introduction to the volume by Dr. Sidis, the theory of mental dissociation is brought forward as the guiding principle and explanation of the cases which are reported in detail in the subsequent chapters. Briefly stated, the theory maintains that in functional mental disease the disorder is to be traced to the loss of synthesis and unity in mental life. Certain systems of ideas which become split off or separated from the highest level of consciousness, exist in the form of subconscious experience or personality. These dissociated systems may give rise to many different pathological phenomena, such as anaesthesia and amnesia ; they may persist in the subconscious form, or may occa- sionally take their place as dominant factors in the upper, waking, consciousness. With this explanation the mode of cure is indicated ; the whole mental life is to be reassociated and unified, this process being accompanied by the ejection or modification of such factors as are incom- patible with normal healthy life. In connexion with the psychological view we may refer to the stages of degeneration of the neurone as classified by Dr. Sidis. First there is disaggregation of whole systems of neurones which have suffered no organic lesion : in the next stage the neurone itself is affected, but is capable of recovery : in the last stage, exemplified in general paralysis, injury is so great that recovery is im- possible. In several chapters which follow the introduction, Dr. Sidis gives his views on the general subject of psychopathological research : he insists on the principle of reducing complex problems to simple and accessible forms and lays stress on the study of functional psychosis as preparing the way for a study of more complex problems. It might have been expected that in this general discussion some reference would be made to the work of the German school of psychopathological research. The patients, whose cases are studied and presented as typical of many others, include a girl who suddenly developed maniacal symptoms, a man who completely lost recollection of recent events owing to an over- dose of alcohol, a young woman whose symptoms were those of psychic epilepsy, a man who developed a firmly rooted depressive delusion, a young woman presenting localised motor disturbance, and lastly a man showing ordinary symptoms of epilepsy. In nearly all the cases the chief method pursued is that of analysing the patient's mental condition and elucidating his past history by the ordinary methods of hypnotism, by the method of distraction, and by a method devised by Dr. Sidis, and termed hypnoidisation, which consists in noting the ideas which spon- taneously appear in the subject's consciousness while his attention is concentrated on some object. In some cases the patient's sensibility is examined ; the unconscious reactions are also registered by the graphic method, the plates at the end of the volume being reproductions of graphic records which have been taken. By these means the authors consider themselves able to give an exact account of the subconscious detached mental systems ; this knowledge prepares the way for the application of suggestion in its various modifications to the problem of mental recovery. The authors record that in each of the cases decided success attended their efforts to restore mental equilibrium. It is interesting to notice the successful result in the delusional case, which is analysed with great care, and to compare with this the view of Kraepelin that it is not possible to remove fixed delusions by means of hypnotism. ,The notes and descriptions of the cases might with advantage have been condensed and more thoroughly arranged. The practical aspect of these" investigations is of interest to the alienist rather than to the psychologist. It would not be fair to criticise the