THE LAW OF HABIT. 31 



Human Nature," not only allows the treatment of habit to grow out 

 of his remarks upon instinct and appetite, but even goes so far as to 

 say that " the genesis of habits is fully explained by the existence of 

 natural appetites and instincts." But we must not forget that, while 

 the connection between them is confessedly intimate, it is no closer 

 than that which exists between habit and any of the other tendencies 

 or impulses of our nature, for each of these, equally with our 

 instinctive or appetitive tendencies, will lead, if exercised, to the 

 formation of a habit. Besides, however close the relation subsisting 

 between the phenomena indicated may be, it yet remains that habit 

 is neither instinct nor appetite. The word "appetite" is properly 

 used only as referring to those impulsive states of feeling which are 

 characterized by periodicity. They may be primitive and natural, 

 such as hunger, thirst, sleep, &c., or they may be induced through 

 continued indulgence, e. y., the appetite for tobacco; but whatever 

 their variety or origin, our appetites are mei-ely states of feeling pro- 

 duced by the periodically recuiring wants and necessities of our 

 bodily or organic life, and which prompt to action for their gratifica- 

 tion or alleviation. 



Instincts, on the other hand, differ from appetites in that they are 

 always primitive in the individual, never acquii-ed. An instinct is 

 the ability in any individual to perform actions involving complicated 

 muscular adjustments, particulai'ly such actions as are useful, which 

 ability is untaught, and due to no steps of development or exercise 

 through which the individual has passed. This, however views may 

 diflfer as to the explanation to be given of these primitive facts, is a 

 statement of the essential featiires of instinct. Individuals do, as a 

 matter of fact, without any course of training, and without any 

 causes that can be pointed out in their own experience, possess the 

 ability to perform actions, which, in degree of complexity of the 

 muscular movements involved, rank as high as many actions usually 

 attained only after a process of development has been for some con- 

 siderable time at work. We may note in passing, that upon this 

 fact of primitive instinctive ability for complicated action great light 

 is thrown by the modern doctrine of Evolution. To return, however. 

 In neither of the above classes of phenomena do we find the essential 

 features that mark our habits. What peculiarly belongs to habit as 

 distinguished from instinct and appetite, is that the word draws 

 particular attention to the effects of repeated exercise, and throughout 



