MENTAL EVOLUTION IN ANIMALS. 



CHAITER I. 



The Criterion of Mind. 



The subject of our enquiry being Mental Evolution, it is 

 desirable to begin by understanding clearly what we mean by 

 Mind,* and then defining the conditions under which known 

 Mind is invariably found to occur. In this chapter, therefore, 

 I shall deal with what I take to be the Criterion of Mind, 

 and shall then pass on in the next chapter to a consideration 

 of the objective conditions under which alone Mind is 

 observed to exist. 



It is obvious, then, to start with, that by Mind we may 

 mean two very different things, according as we contemplate 

 it in our own individual selves, or as manifested by other 

 beings. For if I contemplate my own mind, I have an imme- 

 diate cognizance of a certain flow of thoughts and feelings, 

 which are the most ultimate things — and, indeed, the only 

 things — of which I am cognizant. But if I contemplate 

 Mind in other persons or organisms, I can have no such 

 immediate cognizance of their thoughts and feelings ; I can 

 only infer the existence of such thoughts and feelings from 

 the activities of the persons or organisms which appear to 

 manifest them. Thus it is that by Mind we may mean 

 either that which is subjective or that which is objective. 

 Now throughout the present work we shall have to consider 

 Mind as an object ; and therefore it is well to remember that 

 our only instrument of analysis is the observation of activities 



* It was necessary in my work on Animal Intelligence briefly (o touch 

 on this question ; therefore the parts of the analysis vhioh arc common to 

 the two works I sliall render as much ub possible in the same words. 



