22 MENTAL EVOLUTION IN ANIMALS. 



experience, we are in possession of the best available evi- 

 dence of conscious memory leading to intentional adaptation. 

 Therefore, our criterion applies to the upper limit of non- 

 mental action, not to the lower limit of mental." 



Or, again adopting the convenient terminology of Clifford, 

 we must always remember that we can never know the mental 

 states of any mental beings other than ourselves as objects ; 

 we can only know them as ejects, or as ideal projections of our 

 own mental states. And it is from this broad fact of psycho- 

 logy that the difficulty arises in applying our criterion of 

 mind to particular cases — especially among the lower animals. 

 For if the evidence of mind, or of being capable of choice, 

 must thus always be ejective as distinguished from objective, 

 it is clear that the cogency of the evidence must diminish as 

 we recede from minds inferred to be like our own, towards 

 minds inferred to be not so like our own, passing in a gradual 

 series into not-minds. Or, otherwise stated, although the 

 evidence derived from ejects is practically regarded as good 

 in the case of mental organizations inferred to be closely 

 analogous to our own, this evidence clearly ceases to be trust- 

 worthy in the ratio in which the analogy fails ; so that when 

 we come to the case of very low animals — where the analogy 

 is least — we feel uncertain whether or not to ascribe to them 

 any ejective existence. But I must again insist that this 

 fact — which springs immediately out of the fundamental 

 isolation of the individual mind — is no argument against my 

 criterion of mind as the best criterion available ; it teuds, 

 indeed, to show that no better criterion can be found, for it 

 shows the hopelessness of seeking such. 



The other point which has to be noted with regard to this 

 criterion is as follows. I again quote from " Animal Intelli- 

 gence :" — 



" Of course to the sceptic this criterion may appear un- 

 satisfactory, since it depends, not on direct knowledge, but 

 on inference. Here, however, it seems enough to point out, 

 as already observed, that it is the best criterion available ; 

 and, further, that scepticism of this kind is logically bound 

 to deny evidence of mind, not only in the case of the lower 

 animals, but also in that of the higher, and even in that of 

 men other than the sceptic himself. For all objections which 

 could apply to the use of this criterion of mind in the animal 

 kingdom, would apply with equal force to the evidence of any 



