THE 



POPULAR SCIENCE 

 MONTHLY. 



FEBRTJAEY, 1887. 



THE LAWS OF HABIT. 



By Pkofessor WILLIAM JAMES. 



WHEN we look at living creatures from an outward point of view, 

 one of the first things that strike us is that they are bundles of 

 habits. In wild animals, the usual round of daily behavior seems a 

 necessity implanted at birth ; in animals domesticated, and especially 

 in man, it seems, to a great extent, to be the result of education. 

 The habits to which there is an innate tendency are called instincts ; 

 some of those due to education would by most persons be called acts 

 of reason. It thus appears that habit covers a very large part of life, 

 and that one engaged in studying the objective manifestations of mind 

 is bound at the very outset to define clearly just what its limits are. 



The moment one tries to define what habit is, one is led to the 

 fundamental properties of matter. The laws of Nature are nothing 

 but the immutable habits which the different elementary sorts of 

 matter follow in their actions and reactions upon each other. In the 

 organic world, however, the habits are more variable than this. Even 

 instincts vary from one individual to another of a kind ; and are modi- 

 fied in the same individual, as we shall later see, to suit the exigencies 

 of the case. The habits of an elementary particle of matter can not 

 change (on the principles of the atomistic philosophy), because the 

 particle is itself an unchangeable thing ; but those of a compound 

 mass of matter can change, because they are in the last instance due 

 to the structure of the compound, and either outward forces or inward 

 tensions can, from one hour to another, turn that structure into some- 

 thing different from what it was. That is, they can do so if the body 

 be plastic enough to maintain its integrity, and be not disrupted when 

 its structure yields. The change of structure here spoken of need 

 not involve the outward shape ; it may be invisible and molecular, as 

 when a bar of iron becomes magnetic or crystalline through the action 

 vol. xxx. — 28 



