ADDRESS. 23 



•which during the last decade have been conducted with such vigour in 

 all parts of the world, all of them traceable to the influence of the 

 Leipzig school ; but will content myself with saying that the general 

 purpose of these investigations has been to determine with the utmost 

 atlainable precision the nature of psychical relations. Some of these 

 investigations begin with those simpler reactions which more or less 

 resemble those of an automatic mechanism, proceeding to those in which 

 the resulting action or movement is modified by the influence of auxiliary 

 or antagonistic conditions, or changed by the simultaneous or antecedent 

 action on the reagent of other stimuli, in all of which cases the efi'ect 

 can be expressed quantitatively ; others lead to results which do not so 

 readily admit of measurement. In pursuing this course of inquiry the 

 physiologist finds himself as he proceeds more and more the coadjutor 

 of the psychologist, less and less his director; for whatever advantage 

 the former may have in the mere technique of observation, the things 

 with which he has to do are revealed only to introspection, and can be 

 studied only by methods which lie outside of his sphere. I might in 

 illustration of this refer to many recent experimental researches — such, 

 for example, as those by which it has been sought to obtain exact data 

 as to the physiological concomitants of pleasure and of pain, or as to the 

 influence of weariness and recuperation, as modifiers of psychological 

 reactions. Another outwork of the mental citadel which has been 

 invaded by the experimental method is that of memory. Even here it 

 can be shown that in the comparison of transitory as compared with 

 permanent memory — as, for example, in the getting ofi" by heart of a 

 wholly uninteresting series of words, with subsequent oblivion and 

 reacquisition — the labour of acquiring and reacquiring may be measured, 

 and consequently the relation between them ; and that this ratio varies 

 according to a simple numerical law. 



I think it not unlikely that the only efi'ect of what I have said may 

 be to suggest to some of my hearers the question. What is the use of 

 such inquiries ? Experimental psychology has, to the best of my 

 knowledge, no technical application. The only satisfactory answer I 

 can give is that it has exercised, and will exercise in future, a helpful 

 infiuence on the science of life. Every science of observation, and each 

 branch of it, derives from the peculiarities of its methods certain ten- 

 dencies which are apt to predominate unduly. We speak of this as 

 specialisation, and are constantly striving to resist its infiuence. The 

 most successful way of doing so is by availing ourselves of the counter- 

 acting influence which two opposite tendencies mutually exercise when 

 they are simultaneous. He that is skilled in the methods of introspec- 

 tion naturally (if I may be permitted to say so) looks at the same thing 

 from an opposite point of view to that of the experimentahst. It is, 

 therefore, good that the two should so work together that the tendency 

 of the experimentalist to imagine the existence of mechanism where none 



