SCIENCE AND PHILOSOPHY 153 



hand of the past has left its impress on them, but 

 the living hand of the past is on the organism 

 for ever. In the organism, as Bergson says, the 

 past is prolonged into the present. Thus we pass 

 on to a new level of explanation or interpretation 

 which is historical. 



And whenever we mention that the eel is one 

 of a deep-sea race which has adventurously 

 taken to colonizing the fresh waters just as 

 the salmon is one of a freshwater race which has 

 taken to exploiting the sea, and notice further 

 that animals in general return to their birthplace 

 to breed then at once a biological light begins 

 to be shed on the eel's strange story. 



THE "SouL AND BODY" PROBLEM. No one 

 understands how living creatures began to be 

 in pre-Cambrian ages in a lifeless world, and 

 no one understands the innermost secret of their 

 activity. Similarly at a higher level: No one 

 understands how thinking creatures began to 

 be, nor understands what the innermost secret 

 of thinking is. But just as the scientific inquirer 

 has a contribution to make to the discussion of 

 the origin of life and the autonomy of the organ- 

 ism, so he has something to say in regard to the 

 perennial question of the relation between body 

 and mind, a question which is, however, essentially 

 metaphysical. 



The scientific contribution is threefold: 



