THE LAW OF HABIT. 37 



condition of the growth and strength of tendencies in any direction. 

 This fact is at least a finger-post, though admittedly fallible, pointing 

 to similarity in the nature of both. 



(b) Many of the results of habit are apparently completely 

 resolvable into manifestations of contiguous association. Thus, in 

 the case of the so-called " secondarily automatic " actions, as when 

 an accomj)lished pianist commences playing, and the customary trains 

 of muscular movement are kept up without the arising in conscious- 

 ness of their mental concomitants, there is apparently no necessity of 

 recognizing anything else as involved than the mere linking together 

 by contiguous association of a series of muscular movements which 

 have been frequently performed in regular succession, in such a way 

 that the appearance of the first link tends to call up the rest. 



(c) There are no phenomena of habit which are positively known 

 to be incapable of reduction to the outcome of contiguous association, 

 the utmost that can be said being that in some cases we cannot from 

 direct evidence affirm the applicability of the principle of contiguity 

 in explanation. 



(d) Where this inability exists it seems to be accounted for by 

 the empirical limitations upon our knowledge of the facts possibly 

 concerned in the case. For example : — Repetition of exercise on the 

 one hand increases the efficacy of some of our perceiving powers ; the 

 eye becomes more sensitive to shades of color, the ear more acute to 

 apprehend distinctions of sound. But on the other hand, certain of 

 our primary susceptibilities suffer a deadening effect from repetition 

 of affection. Thus the sensibility to heat and cold, to the glare of sun- 

 light, and to hard and rough contact with rude and pungent and hurt- 

 ful agents, lessens under exposure to them. A similar apparently 

 contradictory variety of effects is seen in the case of our emotions. 

 Love, fear, jjride, and other emotions are stimulated by exercise ; 

 but grief, by indulgence, in the healthily constituted nature gradually 

 dies away. Now, it seems difficult to represent these diverse and 

 apparently opposite results as in x-eality mei-ely different manifestations 

 of the working of some one law, such as the principle of contiguity. 

 There is nothing illegitimate, however, in our setting up this account 

 of them as a scientific hypothesis awaiting verification. It is quite 

 possible that all such seemingly opposite dii-ections of the energies of 

 habit may have some common physical basis which farther research 

 into the correlation of mental and organic processes may reveal. It 



