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SCIENCE. 



[N. S. Vol. XXIII. No. 582. 



kinds : (a) generalizations from facts which 

 have at best only a' classificatory and at 

 worst a repeative, attenuated, verbal sense, 

 from which the red blood of meaning has 

 begun to evaporate; (6) attempts at logical 

 interpretation or statements of genus and 

 difference, with the corpses of which the 

 pathway of our science is so thickly strewn 

 and which are usually haunted with all 

 kinds of personal and philosophic biases in 

 which no two agree; (c) those prompted 

 by man's inveterate longing for finality, 

 which have a certain sacrosanct character 

 because they are so satisfying to the author 

 and which, therefore, constitute precious 

 psychological data to be collected and used 

 empirically for future generalizations con- 

 cerning human nature. Of the soul and 

 each of its powers it can be said, as 

 Schleicher said of language, all discussion 

 of the origin and definition of which was 

 long forbidden by the Societe de Linguis- 

 tique, 'Es ist was es wird. ' Thus every 

 new fact in psychology changes the defini- 

 tion of it and, perhaps, makes some older 

 ones obsolete, because the definition of the 

 science is nothing more nor less than the 

 science itself in its present state. Only the 

 tyro in any subject seeks to begin with 

 definitions, while the connoisseur only ends 

 with them if he reaches them at all. But 

 (d) there may be definitions made only for 

 the purposes of speculation or of contro- 

 versy. These should be expressly provi- 

 sional and ought to be transcended at the 

 end of every discussion. My definition of 

 psychology is expressly of the latter kind 

 and is as follows: It is a description as 

 accurate as can be of all those facts of 

 psychic life, conscious and unconscious, 

 animal and human, normal and morbid, 

 embryonic and mature, which are demon- 

 strable and certain to be accepted by every 

 intelligent unbiased mind who fully knows 

 them. They must also be so ordered, like 

 to like, and organized that they can all be 



known with the least effort, and so that 

 each is nearest to that it is most akin. To 

 this I would add that the best principle or 

 organization of these facts, wherever it is 

 justifiable, is evolutionary because the best 

 explanation and definition of anything is 

 a complete description of its developmental 

 stages. From this definition you can fore- 

 see about all I have to say upon this topic. 



Psychology deals with the facts, meas- 

 urable and immeasurable, of sense and the 

 inner life under conditions controlled in 

 the laboratory, with statistics based on 

 large numbers, with the myth, custom, bor 

 lief and language of races, and is excluded 

 from no field of experience, inner or outer, 

 or of life, conscious or unconscious, re- 

 ligious, social, genetic, individual, that can 

 be studied on the basis of valid empirical 

 data. The individual speculator or sys- 

 tem-builder who goes beyond these facts 

 contributes nothing save one more personal 

 set of data for the future generalizer. 

 Consciousness, too, is an island in the midst 

 of the shoreless, unconscious sea, or, better, 

 in Huxley's simile it is a tallow dip illu- 

 minating only one room of the great mu- 

 seum of man-soul. Consciousness can only 

 give us a glimpse of the experience of the 

 individual and hardly that of the race. 

 From this it follows that psychology must 

 more and more rest upon induction and 

 that its closest allies in the future are to 

 be biology, physiology and anthropology. 



What should it exclude? My answer is 

 that it is just as proper, and no more so, 

 for it to concern itself with the relations 

 between mind and body as for physics to 

 speculate about the relations between force 

 and matter. It is no more pertinent for 

 it to discuss parallelism or interaction than 

 it is for abnormal, genetic or comparative 

 psychology to do so. It makes no possible 

 difference for any scientific fact of psy- 

 chology whether the soul is a spirit, a mesh 

 of neurons or a monad in Howison's sense. 



