AN ESSAY ON BIRD-MIND 109 



this emotional content we most definitely find run- 

 ning through the lives of higher animals. 



The objection is easily and often raised that we 

 have no direct knowledge of emotion in an animal, 

 no direct proof of the existence of any purely mental 

 process in its life. But this is as easily laid as raised. 

 We have no direct knowledge of emotion or any other 

 conscious process in the life of any human being save 

 our individual selves; and yet we feel no hesitation 

 in deducing it from others' behaviour. Although 

 it is an arguable point whether biological science may 

 not for the moment be better served by confining the 

 subject-matter and terms of analysis to behaviour 

 alone, it is a very foolhardy "behaviorist" indeed who 

 denies the existence of emotion and conscious process! 



But the practical value of this method of thinking 

 is, as I say, an arguable point; it is indeed clear that 

 a great immediate advance, especially in non-human 

 biology, has been and may still be made by translat- 

 ing the uncertain and often risky terms of subjective 

 psychology into those based upon the objective de- 

 scription of directly observable behaviour. How- 

 ever, it is equally easy to maintain, and I for one 

 maintain it, that to omit a whole category of phe- 

 nomena from consideration is unscientific, and must 

 in the long run lead to an unreal, because limited, 

 view of things; and that, when great detail of analy- 

 sis is not required, but only broad lines and general 

 comparison, the psychological terminology, of mem- 



