354 THE CONCEPT OF EVOLUTION 



tionary hypotheses concretely is hardly older than Darwin, 

 and the shortness of human life is discouraging to experi- 

 mentation with organisms. The results of many years are 

 usually small in amount It is only now and then that a 

 pioneer like Mendel is able to take a great stride, and to 

 give his successors a clue that enables them to take others. 

 Impatient therefore of the slow but sure inductive method, 

 naturalists are ever flying kites of hypotheses and there is 

 no department of science so wordy as aetiology. 



On the other hand, one of the difficulties is that we have 

 too few words. The same word is used with many meanings, 

 and, like a tool put to many uses, becomes blunted and falla- 

 cious. So is it with the word ' evolution '. 



Whatever be his personal classification every one recog- 

 nises that there are in our world three spheres which overlap 

 one another. There is the cosmosphere from the solar sys- 

 tem to the dew-drop, from the moon to the moonstone, from 

 the sea to the snow-crystal the Domain of the Inorganic, 

 where formulations are in terms of matter and motion 

 formulations, which, whether they exhaust the reality or not, 

 get close enough to it to be thoroughly reliable for practical 

 purposes and ventures. 



Secondly, there is the biosphere, the Realm of Organisms, 

 where the laws of matter and motion still hold, but are no 

 longer exhaustive, since another aspect of reality has welled- 

 up, which we call life. And since even simple un-bodied 

 creatures go a-hunting and show purposive behaviour, we 

 find it difficult to separate off life from mind. We cannot 

 say much about plants which we do not know how to waken 

 from their dreams, but for the animal world we have clearly 

 to do in any typical case with a Body-Mind or Mind-Body. 



Thirdly, there is the sociosphere, the Kingdom of Man, 



