June 24, 1898.] 



SCIENCE. 



863 



strange monument in the history of science find 

 also somewhere speedy reissue ? 



George Bruce Halsted. 

 Austin, Texas. 



The Psychology of Suggestion. By Boris Sidis, 

 M.A., Ph.D., Associate in Psychology at the 

 Pathological Institute of the New York State 

 Hospitals. With an Introduction by Pro- 

 fessor William James, of Harvard Univer- 

 sity. New York, D. Appleton & Co. 1898. 

 Dr. Sidis divides his book into three parts, 

 entitled, respectively, 'Suggestibility,' 'The 

 Self,' and ' Society.' The interest of the first cen- 

 ters in two series of laboratory experiments and 

 is intended to establish the ' Laws of Normal 

 and Abnormal Suggestibility. ' The second aims 

 at establishing in every human being the exis- 

 tence of a 'Subwaking Self,' determining its 

 intrinsic character, its relation to the primary 

 self, its physiological conditions, and its rela- 

 tion to the phenomena of amnesia and insanity. 

 The third ascribes to the activity of the sub- 

 waking self, stampedes, social epidemics, and 

 in general the peculiar traits of crowd and mob 

 psychology. 



Suggestion is defined as ' the intrusion into 

 the mind of &n idea ; met with more or less 

 opposition by the person ; accepted uncritically 

 at last ; and realized unreflectively, almost 

 automatically.' 



This definition has obviously been framed 

 with the thought of normal suggestibility in 

 mind, for in states of heightened, or, as Dr. 

 Sidis would term it, abnormal suggestibility, 

 the idea frequently meets with no opposition 

 whatever. Nothing is more common than to 

 see such patients anxiously consider and de- 

 liberately realize the suggestions given them. 

 To make it apply throughout, the suggestion 

 should be described as an idea which would be 

 met with more or less opposition in the normal 

 state, but which in the normal state is accepted, 

 usually uncritically, and realized, often unre- 

 flectively, while in the abnormal state it meets 

 with little or no opposition. 



,Yet even as thus amended, the definition 

 would require us to show, before any intruded 

 and realized idea can be termed a suggestion, 

 that it would have met with opposition, of which 



we have usually no better criterion than such 

 as our knowledge of the tastes and habits of 

 the individual in question can supply. 



In Dr. Sidis' series of experiments he en- 

 deavored, by very ingenious means, to determine 

 the subject's flow of ideas or to afiect hi^ choice 

 of a limited number of alternatives without 

 attracting his attention to the method by which 

 he was influenced. The results are interesting, 

 although one would like to have more precise 

 information as to the conditions under which 

 they were obtained. The main conclusion which 

 Dr. Sidis deduces from these experiments he 

 generalizes into the ' Law of Normal Suggesti- 

 bility ' — ' Normal Suggestibility varies as indi- 

 rect suggestion and inversely as direct sugges- 

 tion.' Then after a review of the phenomena of 

 hypnosis, he sets over against this ' The Law of 

 Abnormal Suggestibility,' which 'varies as direct 

 suggestion and inversely as indirect suggestion.' 



Unfortunately, the distinction between direct 

 and indirect suggestion has nowhere been de- 

 fined. From the illustrations given, however, 

 we may infer that a suggestion is indirect when 

 it is so administered that it never passes beyond 

 the marginal region. It then remains a mere 

 seed upon the surface of consciousness, never 

 strikes its roots down into the depths below, i» 

 merely apprehended and not comprehended. A 

 normally repugnant intruded idea will then be 

 less likely to arouse opposition and more likely 

 to gain its ends if indirect than if direct, and the 

 first law may be accepted as so far true even 

 without experimental verification. But it should 

 be noted that the numerous cases in which the 

 opposition of the self-consciousness to a direct 

 suggestion is overborne by sheer superior 

 strength of will must be relegated to the class 

 of abnormal suggestions — a more than question- 

 able proceeding. 



The second law, however, is by no means 

 true. Increased susceptibility to direct sugges- 

 tion does not carry with it diminished suscepti- 

 bility to indirect suggestion. In states of 

 heightened suggestibility, susceptibility to sug- 

 gestion has no significant relation to the mode 

 in which the suggestion is administered, but 

 rather to the source whence it comes. A subject 

 who is acutely sensitive to every suggestion, 

 direct or indirect, that emanates from the person 



