November 25, 1921] 



SCIENCE 



519 



The problem is not men. From the psycho- 

 logical side it was assailed by William 

 James especially in his later years and since 

 then it has been attacked from the philoso- 

 phical and logical side by the American 

 school of so-called new realists, Professor R. 

 B. Perry, Mr. E. B. Holt, and others. With 

 what results? By James, consciousness re- 

 garded as an entity, was rejected outright. 

 According to his view, the world is not 

 fundamentally composed of two different 

 things, mind and matter; it consists of one 

 " primal stuff," which he called, somewhat 

 unhappily, " pure experience " ; between por- 

 tions of the primal stuff there are various 

 sorts of relations, which are parts of the 

 stuff and of which the portions are the terms; 

 one kind of the relations is called " know- 

 ing " ; such a relation has two terms, one 

 of which is called the " knower " and the 

 other the " known." In James's view, that 

 is the common goal of the two tendencies I 

 have mentioned; that is the truth that is be- 

 ing approached by psychology from the one 

 side and by physics from the other. And 

 the finding of the new realists is much the 

 same. Rejecting the unfortunate term " pure 

 experience," they maintain that what is 

 called mind and what is called matter are 

 both of them composed of a, " neutral-stuff " 

 which is in itself neither mental nor material, 

 neither mind nor matter. 



Russell deals with the problem in the light 

 of the foregoing views but he handles it 

 afresh, in a way that is quite his own, bring- 

 ing to the task a native and acquired equip- 

 ment — logical, mathematical, philosophical — 

 that gives his work surpassing importance. 

 What is his main conclusion and how is it 

 related to that of James and his American 

 disciples? Russell, like James, rejects con- 

 sciousness regarded as an entity; neither is 

 consciousness an essential quality or a simple 

 companion of mental phenomena. " Con- 

 sciousness " he finds to be "a complex and 

 far from universal characteristic of mental 

 phenomena." In holding that " sensations are 

 what is common to the mental and physical 



worlds," that sensations are literally " the 

 intersection of mind and matter," he agrees 

 with the American realists and with Ernst 

 Mach ; ^ and so, with respect to sensations, 

 he agrees with the realists in the thesis that 

 the world is composed of a " neutral-stuff " ; 

 but he does not agree with them in his main- 

 taining that images are not reducible to 

 sensations and in his conclusion that " im- 

 ages belong only to the mental world." The 

 final conclusion is: 



All our data, both in physics and psychology, are 

 subject to psychological causal laws; but physical 

 causal laws, strictly speaking, can only b© stated 

 in terms of matter, which is both inferred and con- 

 structed, never a datum. In this respect psychology 

 is nearer to what actually exists. 



How are the results arrived at? The 

 answer can not be given in a brief review, 

 and the reader must be referred both to this 

 volume and to its companion " Our Knowl- 

 edge of the External World " published a 

 few years ago. The earlier work, which 

 deals with the physical aspects of the same 

 problem, is chiefly concerned with the ques- 

 tion whether, how, and to what extent the so- 

 called constituents of matter are construc- 

 tible out of sense-data by logical processes. 

 The two works are thus complemental, to- 

 gether constituting a whole. 



Suffice it to say that, so far as the present 

 volume is concerned, the results are reached 

 by a diabolically ingenious analysis of such 

 things as instinct and habit, desire and feel- 

 ing, psychological and physical causal laws, 

 introspection, perception, sensations and im- 

 ages, memory, words and meaning, general 

 ideas and thoughts, belief, truth and false 

 hood, emotions and will; and by an equally 

 ingenious synthesis, or logical construction, 

 making many familiar things seem strange 

 — desire, for example, appearing as a mere 

 " fiction " like force in dynamics — and show- 

 ing many seemingly simple and primitive 

 things to be complex and derivative. It is 

 noteworthy that the least original and weak- 

 est part of the analysis is that of the emo- 

 tions and will, commonly regarded as mental 



1 " Analysis of Sensations, 1886." 



