32 



HABIT AND INTELLIGENCE. 



[chap. 



Voluntary 

 actions 

 may 

 become 

 con- 

 sensual. 



Instance 

 of a 

 musician. 



This may 

 become 

 hereditary 

 in animals, 

 as in birds, 



and in 

 dogs. 



This ex- 

 planation 

 will not 

 apply to 

 all con- 

 sensual 

 actions. 



ganglionic substance of the cerebrum are the nerves of 

 consciousness. I suppose, consequently, that when action 

 is purely voluntary, the process is this : A current in the 

 nerves of thought (which, as stated above, are not in direct 

 connexion with either the sensory or the motor ganglia) — 

 a current in the nerves of thought, I say, determines a 

 current in the nerves of will ; and this acts on the motor 

 ganglia, so as to determine muscular action, exactly as a 

 current of sensation would do. 



It is a very important fact, that actions wliich were 

 voluntary at first may become consensual through habit. 

 The best instance of this is afforded by the act of learning 

 any manual art, especially music. In learning to play 

 from printed notes, every movement of the fingers must at 

 first be made to correspond with the notes by a conscious 

 and voluntary determination; but by long practice the 

 intermediate links of consciousness and will may be 

 gradually left out, and the motions of the fingers may be 

 consensually directed by the sight of the printed notes. 

 In man, the greater part of what have become consensual 

 actions, have become so by such a process. Even the act 

 of walking is not instinctive in chDdren, or in other words 

 is not originally consensual, but has to be learned. Among 

 many animals, actions that were voluntary at first have 

 not only become consensual in the individual, but, by 

 hereditary transmission, have become so in the race. One 

 instance of this is the tendency to fly from man which, as 

 mentioned in the preceding chapter, has become hereditary 

 among many races of birds to which it was not originally 

 natural. But the acquired instincts of the domestic races 

 of dogs are yet more remarkable. Young pointers often 

 point the first time they are taken out ; and Darwin states 

 that the tendency to rim round a flock of sheep instead of 

 at them has become hereditary in the sheep-dog. 



But are all consensual and instinctive actions to be 

 thus accounted for? — in other words, were all consensual 

 actions voluntary at first, and have they only become con^ 

 sensual through habit ? Were we to study man only, we 

 could scarcely avoid the conclusion that such is the case ; 



