No. 554] ADAPTATION IN LIVING AND NON-LIVING 79 



matter, so that we put the floating adaptation of these 

 pebbles entirely out of mind as soon as we begin our 

 search for the causes thereof. 



Geology, it seems, does not find purposeful action nec- 

 essary in its explanations. Neither does any progress 

 come from a consideration of purposeful changes in the 

 readjustments of atoms with which chemistry deals, nor 

 in the phenomena of heat migration which constitute a por- 

 tion of the field of physics. Modern astronomy sees no 

 purposeful activity in the motions of sidereal space, nor 

 does meteorology seek in the effects of a storm any sugges- 

 tion of the causes which brought it into being. Many 

 branches of biological science, however, although confess- 

 edly not dealing with human purposeful activity, seem 

 frequently to seek in the future the causes of the present. 

 Thus our science teems with purposeful reactions, and 

 this feature of the idea of adaptation adds its influence to 

 the ones already mentioned, playing an important role in 

 keeping the sciences of the non-living essentially and fun- 

 damentally separate from those of the living. 



The history of the idea of causation in the natural sci- 

 ences suggests much that may have a bearing on our 

 judgment as to whether this present distinction between 

 the two groups of sciences is necessary and permanent or 

 merely temporary and passing. To primitive man all 

 problems were too complex for adequate analysis, and 

 purposeful activities of many kinds were devised to ex- 

 plain not only the doings of his fellow men but also the 

 doings of all nature. The whole world was then a world 

 of teleological causation. The heavenly bodies moved 

 and the chemical elements combined or separated accord- 

 ing to the capricious wills of innumerable deities and 

 demons. Men then heard in the howling of the storm 

 and in the rumble of the earthquake the terrible voices of 

 the spirits of the air and earth. All living things were en- 

 dowed with a man-like consciousness and power of will- 

 ing to do, and everything struggled with everything else- 

 in a never-ending conflict of capricious wills. 



