42 THE BEGINNINGS OF LIFE. 



The molecular motion or energy, set free in the ner- 

 vous system, subserves very different purposes. Upon 

 evidence which cannot now be gone into, it could be 

 shown (a) that the nervous system plays an important 

 part in regulating the various secretions and in in- 

 fluencing the nutrition of the body generally. It is 

 nerve-force again (&) which initiates or calls into play 

 the activity of the various muscles by which the count- 

 less movements within the bodies of animals are pro- 

 duced, and also those by which locomotion and external 

 visible movements generally are effected. But nerve- 

 changes also (c) give rise to other manifestations mani- 

 festations altogether peculiar in kind and peculiar to the 

 individual in whom they occur. Feeling is the basis of 

 Consciousness, and this is a property sui generis, which is 

 believed to be called into existence by the action or 

 occurrence of molecular changes within certain parts of 

 the brain *. 



Whilst the manifestation of mental phenomena, in 



1 ' Feeling of whatever kind is directly known by each person in no 

 other place than his own consciousness. That feelings exist in the world 

 beyond consciousness is a belief reached only through an involved com- 

 bination of inferences. That, alike in human and inferior beings, feel- 

 ings are accompaniments of changes in the peculiar structure known as 

 the nervous system, is also an indirectly established belief. And that 

 the feelings alone cognizable by any individual are products of the 

 action of his own nervous system, which he has never seen, and on 

 which he can try no experiments, is a belief only to be arrived at through 

 a further chain of reasoning. Nevertheless, the evidence, though so 

 indirect, is so extensive, so varied, and so congruous, that we may ac- 

 cept the conclusion without hesitation.' Herbert Spencer, 'Principles 

 of Psychology,' 1869, p. 128. 



