December 22, 1911] 



SCIENCE 



879 



Psychologists will ■welcome Professor Pills- 

 bury's systematic attempt to treat human psy- 

 chology in terms of behavior. It is unusual 

 for a text-book on psychology to view human 

 activity from an objective standpoint, and it 

 ia not easy to retain this point of view con- 

 •istently. 



The author defines psychology as " the sci- 

 ance of human behavior" (p. 1). This lim- 

 itation of the field is open to two objections: 

 (1) it seems to exclude animal behavior from 

 psychology, which is particularly undesirable 

 in an objective discussion; and (2) it appar- 

 ently discriminates against introspection. 

 The latter criticism, however, is met by a 

 broad use of the term " behavior " ; Professor 

 Pillsbury treats mental processes as antece- 

 dents of behavior, and includes the usual dis- 

 «ussion of sensation, perception, memory, feel- 

 ing and other phenomena of consciousness. 



The structure and functions of the nervous 

 •ystem are thoroughly discussed in two chap- 

 ters. The real nervous basis of consciousness 

 is found in the synapses. According to this 

 Tiew, habit-formation probably involves a per- 

 manent lessening of tension at the synapse, 

 rather than a modification within the neurone. 

 The author seeks to mediate between func- 

 tional and structural psychology. All psycho- 

 logical facts are reduced to three fundamental 

 principles: " The first is that all mental quali- 

 ties come originally from sensation. . . . The 

 second principle is that the order in which 

 mental processes of any sort enter conscious- 

 ness and whether any process does or does not 

 •nter consciousness, depends upon the nature 

 of the individual rather than upon the forces 

 in the physical world. . . . The third and last 

 of these principles is that experiences leave a 

 disposition in the nervous system that tends 

 to the reinstatement of that experience on 

 •uitable occasion" (p. 153). This provides 

 three elementary facts — sensation, attention 

 and retention — ^which may be regarded as 

 •ither elements or processes. 



Sensation, according to the author, stands 

 in a specially close relation to the nervous 

 lystem. " The development of the sense 



qualities depends upon and goes hand in hand 

 with the development of the sensory endings. 

 In the simplest organisms there is no differ- 

 entiation of sensory organs, and consciousness 

 probably shows no differences whatever " (pp. 

 62-63). The rise of the four skin senses is 

 described first, then the higher senses, finally 

 the kinesthetic, static and organic. The in- 

 tricate topic of vision is exceedingly con- 

 densed, and the author scarcely does justice 

 to the difficulties which have produced rival 

 theories. We find here the parodoxical state- 

 ment that " the retina is a part of the brain 

 that in the course of development has come 

 to the surface" (p. 86, cf. p. 132). 



The chapters on feeling and emotions are 

 very suggestive. The author makes feeling 

 distinct from sensation: "Feelings are sub- 

 jective, sensations objective" (p. 260). It is 

 not clear how this can be reconciled with the 

 earlier statement that " all mental qualities 

 come originally from sensation " (p. 153). 

 Nor does the position of these chapters fur- 

 nish a clue; they follow instinct, which comes 

 after perception, memory and reasoning, 

 though the emotions are regarded as " inter- 

 mediate between feelings and instincts and 

 the higher intellectual operations " (p. 272). 



After discussing sensation, attention and 

 retention Professor Pillsbury proceeds to more 

 complex phenomena. The chapter on percep- 

 tion contains a very full account of visual 

 space perception and optical illusions. By 

 some oversight tactual space is omitted. The 

 chapter on memory and imagination contains 

 a very helpful discussion of the laws of learn- 

 ing and the laws of retention and forgetting. 

 On the neural side " learning is the result of 

 producing changes in the synapses, retention 

 depends on the persistence of the impression ; 

 forgetting, upon its disappearance" (p. 194). 

 The author is strongly opposed to artificial 

 memory systems, which in his opinion require 

 more effort than they save. 



The analysis of intellect and its growth 

 needs amplification. Imagination is treated 

 in about a page, while abstraction is given no 

 independent examination whatever. The dis- 



