XV.] THE LAWS OF HABIT. 173 



and figs of thistles." But I agree with Darwin in be- I believe 

 lieving that there is no limit to the possible extent of ^^ ^g^^.-^^^, 

 variation acting cumulatively, if only a sufficient number tiou- 

 of generations is allowed; — no limit, I mean, as to the 

 possible extent of change : there are, I believe, definite laws 

 as to its direction. Of these laws we know but little ; it 

 is, however, a very important truth, that variation does not 

 go on equally in all directions at once, but takes place in 

 particular directions at particular times : in other words, 

 organisms acquire habits of varying in particular direc- Habits of 

 tions ; and these habits of varying are characteristic not '^^'y"^"' 

 only of individuals but of species and genera; perhaps 

 we may say, of whole classes. As an instance of this — 

 not by any means the strongest instance I can think of, 

 but the most familiar — may be mentioned the well-known 

 fact that the acquisition of any power that depends on 

 habit makes it easier to acquire other powers of the same 

 kind : thus, the mastering of one language makes it easier Instance 

 to master other languages. This is not simply a case of a i*ng lan"' 

 habit perpetuating itself. The knowledge of any language gw^ges. 

 consists in the habitual connexion in the mind between 

 the words of the language and the ideas they represent, so 

 that the one will recall the other without effort ; and these 

 connexions are different for every different language. But 

 though the habitual connexions are different, the habit 

 which is cultivated in acquiring them for one language 

 facilitates their acquisition for another : a habit has been 

 acquired of acquiring a particular kind of habits. This 

 law, that organisms acquire a habit of varying, or, in other 

 words, of altering their habits in particular directions, is 

 shown by Darwin to be true of the formative functions as 

 well as of the motor and mental ones ; and he has clearly 

 perceived its great importance in accounting for the origin 

 of species. I shall have more to say on this subject in a 

 future chapter. 



Habits, as we have seen, are formed and strengthened 

 by repetition of the acts. This, indeed, is only a state- 

 ment of the elementary law of habit. The converse is 

 also true : habits are weakened, and may at last be weakened 



