INTRODUCTION. 9 



those which are manifested by man, sufficiently prove 

 the existence of mental states analogous to those in man 

 of which these expressions are the outward and visible 

 signs. But when we find an ant or a bee apparently 

 exhibiting by its actions these same emotions, few persons 

 are sufficiently non-sceptical not to doubt whether the 

 outward and visible signs are here trustworthy as evidence 

 of analogous or corresponding inward and mental states. 

 The whole organisation of such a creature is so different 

 from that of a man that it becomes questionable how 

 far analogy drawn from the activities of the insect is a 

 safe guide to the inferring of mental states particularly 

 in view of the fact that in many respects, such as in the 

 great preponderance of * instinct ' over ' reason,' the 

 psychology of an insect is demonstrably a widely different 

 thing from that of a man. Now it is, of course, perfectly 

 true that the less the resemblance the less is the value of 

 any analogy built upon the resemblance, and therefore 

 that the inference of an ant or a bee feeling sympathy or 

 rage is not so valid as is the similar inference in the case 

 of a dog or a monkey. Still it is an inference, and, so 

 far as it goes, a valid one being, in fact, the only in- 

 ference available. That is to say, if we observe an ant or 

 a bee apparently exhibiting sympathy or rage, we must 

 either conclude that some psychological state resembling 

 that of sympathy or rage is present, or else refuse to 

 think about the subject at all ; from the observable facts 

 there is no other inference open. Therefore, having full 

 regard to the progressive weakening of the analogy from 

 human to brute psychology as we recede through the 

 animal kingdom downwards from man, still, as it is the 

 only analogy available, I shall follow it throughout the 

 animal series. 



It may not however, be superfluous to point out 

 that if we have full regard to this progressive weaken- 

 ing of the analogy, we must feel less and less certain 

 of the real similarity of the mental states compared ; 

 so that when we get down as low as the insects, I 

 think the most we can confidently assert is that the 

 known facts of human psychology furnish the best avail- 



