THE PROBLEM OF BODY AND MIND 231 



ico-physical description has yet been given of any distinc- 

 tively vital process. A new aspect of reality wells up within 

 organisms, which are material systems none the less, and 

 we require new concepts for its description. Even in their 

 simplest forms organisms are integrated systems, capable 

 of unified regulatory action and of registering experiences. 

 But just as the mechanical description has its limitations, 

 so is it with the biological. In our study of Animal Be- 

 haviour we have seen evidence of the gradual disclosure 

 of another aspect of reality which transcends the biological. 

 Mentality wells up from the spring. It appears at first in 

 traces only, so that we are not quite sure whether it is there 

 or not, just as it is not very easy to be sure whether a 

 calcareous Alga, or a dormant chrysalis, or a hibernating 

 snail is living or not. But by and by there is a copious 

 flow, and we have no hesitation in saying that the rook or 

 the parrot, the dog or the elephant, has a mind of its own. 

 The student of science is organically more interested in es- 

 tablishing the fact that the study of living things requires 

 concepts which are not needed in the study of the heavenly 

 bodies, than in a discussion of what, in principle, is meant 

 by Life. Similarly he is more interested in establishing the 

 fact that the study of animal behaviour and not in its 

 higher reaches only requires concepts which are not needed 

 in the study of the everyday functions of the body, than 

 in a discussion of what we mean by Mind. But we cannot 

 be satisfied without at least facing the old problem of the 

 relation between body and mind. It is in reality a meta- 

 physical question, but the metaphysical interpretation must 

 be consistent with what we know of the facts, and we shall 

 begin by stating what must be recognised from the bio- 

 logical side. 



