INTRODUCTION. 3 



ties, on pinching or tickling his feet they are drawn sud- 

 denly away from the irritation, although the man is quite 

 unconscious of the adaptive movement of his muscles ; 

 the lower nerve-centres of the spinal cord are competent 

 to bring about this movement of adaptive response with- 

 out requiring to be directed by the brain. This non- 

 mental operation of the lower nerve-centres in the pro- 

 duction of apparently intentional movements is called 

 Eeflex Action, and the cases of its occurrence, even within 

 the limits of our own organism, are literally numberless. 

 Therefore, in view of such non-mental nervous adjust- 

 ment, leading to movements which are only in appearance 

 intentional, it clearly becomes a matter of great difficulty 

 to say in the case of the lower animals whether any action 

 which appears to indicate intelligent choice is not really 

 action of the reflex kind. 



On this whole subject of mind-like and yet not truly 

 mental action I shall have much to say in my subsequent 

 treatise, where I shall be concerned among other things 

 with tracing the probable genesis of mind from non- 

 mental antecedents. But here it is sufficient merely to 

 make this general statement of the fact, that even within 

 the experience supplied by our own organisms adaptive 

 movements of a highly complex and therefore apparently 

 purposive character may be performed without any real 

 purpose, or even consciousness of their performance. It 

 thus becomes evident that before we can predicate the 

 bare existence of mind in the lower animals, we need 

 some yet more definite criterion of mind than that .which 

 is supplied by the adaptive actions of a living organism, 

 howsoever apparently intentional such actions may be. 

 Such a criterion I have now to lay down, and I think it is 

 one that is as practically adequate as it is theoretically 

 legitimate. 



Objectively considered, the only distinction between 

 adaptive movements due to reflex action and adaptive 

 movements due to mental perception, consists in the 

 former depending on inherited mechanisms within the 

 nervous system being so constructed as to effect particular 

 adaptive movements in response to particular stimula- 



