8 P8YCII0L0O T. 



Shall the study of such machiue-like yet purposive acts aa 

 these be included iu Psj^chology ? 



The boundary line of the mental is certainly vague. It 

 is better not to be pedantic, but to let the science be as 

 vague as its subject, and include such phenomena as these 

 if by so doing Ave can throw any light on the main business 

 in hand. It will ere long be seen, I trust, that we can ; 

 and that we gain much more by a broad than by a narrow 

 conception of our subject. At a certain stage in the devel- 

 opment of every science a degree of vagueness is what 

 best consists with fertility. On the whole, few recent for- 

 mulas have done more real service of a rough sort in psy- 

 chology than the Spencerian one that the essence of mental 

 life and of bodily life are one, namely, * the adjustment of 

 inner to outer relations.' Such a formula is vagueness 

 incarnate; but because it takes into account the fact that 

 minds inhabit environments which act on them and on 

 which they iu turn react ; because, in short, it takes mind 

 in the midst of all its concrete relations, it is immensely 

 more fertile than the old-fashioned ' rational psychology,' 

 which treated the soul as a detached existent, sufficient 

 unto itself, and assumed to consider only its nature and 

 properties. I shall therefore feel free to make any sallies 

 into zoology or into pure nerve-physiology which may 

 seem instructive for our purjDoses, but otherwise shall leave 

 those sciences to the physiologists. 



Can we state more distinctl}^ still the manner in which 

 the mental life seems to intervene between impressions 

 made from without upon the body, and reactions of the 

 bod}^ upon the outer world again ? Let us look at a few 

 facts. 



If some iron filings be sprinkled on a table and a mag- 

 net brought near them, they Avill fly through the air for a 

 certain distance and stick to its surface. A savage see- 

 ing the phenomenon explains it as the result of an attrac- 

 tion or love between the magnet and the filings. But 

 let a card cover the poles of the magnet, and the filings 

 will press forever against its surface without its ever oc- 

 curring to them to pass around its sides and thus come into 



