518 



SCIENCE 



[N. S. Vol. LIV. No. 1404. 



parts of the beautifully illustrated mono- 

 graph on Britisli Annelids by Professor W. 

 C. Mcintosh, a work that will probably be 

 priced to the public at over two guineas. 



The income of the society is derived al- 

 most entirely from its list of subscribers and 

 it is imperative, if the society is to continue 

 its activities, that this list be enlarged. It 

 is, therefore, hoped that American natural- 

 ists will show their appreciation of the good 

 work of the Eay Society by giving it their 

 hearty support. The annual subscription of 

 one guinea should be sent to the secretary of 

 the society. Dr. W. T. Caiman, 1 Mount Park 

 Crescent, Ealing, London, W. 5, England. 

 G. H. Parker 



Harvard University 



SCIENTIFIC BOOKS 



The Analysis of Mind. By Bertrand Eus- 

 SELL, F.E.S. New York: The Macmillian 

 Company. Pp. 310. 1921. 

 It would not be difScult to show that in 

 the course of the centuries mathematical de- 

 velopments were much retarded, sometimes 

 arrested or diverted from their natural course, 

 by an unenlightened psychology and espe- 

 cially by a crude psychology of mathematics. 

 The fact is evident both in the history of 

 algebra and in that of geometry. iNot only 

 was the development of the number concept 

 hampered, but the advent of the concepts of 

 hyperspace and non-Euclidean geometry was 

 delayed for two thousand years, by a psycho- 

 logy that in things mathematical often did 

 not know a knee from an elbow. It is, there- 

 fore, a special pleasure to note and to wel- 

 come the appearance of a psychological work 

 by an eminent contributor to the literature 

 of mathematical foundations. Compared with 

 the work which has been done in the logic 

 of mathematics, that which has been done in 

 the psychology of the subject is exceedingly 

 meager, and the explanation is obvious: 

 mathematicians have been psychologically 

 incompetent, and psychologists mathematic- 

 ally incompetent, to deal with the matter. 

 The work in hand is indeed not specifically 

 concerned with the psychology of mathe- 



matics; its scope is general; but it is likely 

 to awaken psychological interest among mathe- 

 maticians and may incite some of them to 

 study the psychological aspects of their own 

 science. 



This volume consists of a course of lectures 

 given in London and Peking. Its motive is 

 a primarily logical one for the work has 

 sprung out of the seeming discordance of two 

 present scientific tendencies, one of them 

 in psychology, the other in physics; the 

 former may be called a tendency to material- 

 ize mind ; the latter, a tendency to " spiritu- 

 alize" matter; they are both of them metho- 

 dological rather than metaphysical. The 

 former tendency, most notably represented 

 by the behaviorist school of psychologists 

 (like Professor Watson, for example), is 

 manifest in the distrust of introspections as 

 a means to knowledge of mental phenomena 

 and in the growing dependence of psychology 

 upon external observation of animal and hu- 

 man behavior and upon physiological experi- 

 ment, as if matter were regarded " as some- 

 thing much more solid and indubitable than 

 mind." The other tendency, most notably 

 represented by workers (like Professor Ein- 

 stein, for example) in physical theories of 

 relativity, is manifest in the increasing in- 

 clination of physicists to regard " events " 

 as primary and to derive " matter " from 

 them, or to make it out of them, by the proc- 

 esses of logical construction. 



If we regard both of these counter tenden- 

 cies as being in the main sound, as Mr. Eus- 

 sell regards them, they confront us with a 

 certain logical problem which every one 

 must feel the challenge of and which Eus- 

 sell, owing to a highly refined logical sensi- 

 bility, feels with especial keenness. The prob- 

 lem is that of reconciling the two tendencies, 

 seemingly so inconsistent; it is the problem 

 of determining their joint significance; the 

 two tendencies face each other, move towards 

 each other, and, pointing in opposite direc- 

 tions, seem to indicate a common goal — 

 some important truth lying, so to speak, be- 

 tween them, and the problem is to ascertain 

 that truth, if such there be. 



