LIFE 343 



not be sufficient to enable us on the basis of the laws of 

 atomic motion to describe our perceptual experience of 

 life. Such a broad generalisation as that of the con- 

 servation of energy does not appear to be contradicted by 

 our experience of the action of living organisms ; but then 

 the conservation of energy is not the sole factor of 

 mechanism, as some fetish-worshippers nowadays imagine 

 it to be. 



For example, there is the principle of inertia, the state- 

 ment that no physical corpuscle need be conceived as 

 changing its motion except in the presence of other 

 corpuscles, that there is no need of attributing to it any 

 power of self-determination (p. 287). There are probably 

 those who think some power of self-determination must 

 be ascribed to the elementary organic corpuscle, but this 

 seems very doubtful. Placed in a certain field, environed 

 with other organic or inorganic corpuscles, the life-germ 

 moves relatively to them in a certain manner, but there 

 seems no reason to assert (indeed there are facts pointing 

 in the exactly opposite direction) that any change of 

 movement need be postulated were the life-germ entirely 

 removed from this environment. Indeed the whole notion 

 of self-determination as an attribute of living organisms 

 seems to have arisen from those extremely complex 

 systems of organic corpuscles, where the environment in 

 the form of immediate sense -impressions determines 

 change through a chain of stored sense-impresses peculiar 

 to the individual or self (p. 124). But if this be self- 

 determination we can hardly consider it to have any 

 bearing on the simplest forms of life. 



We see, then, that biological change can probably be 

 conceptually described by the change of motion of certain 

 organic corpuscles in the presence of other corpuscles, 

 either organic or inorganic. The structure of these organic 

 corpuscles can further, to a great extent, be described in 

 terms of physical corpuscles. But whether the laws of 

 this motion can be deduced from the laws of motion of 

 physical corpuscles remains at present, and may long 

 remain, an unsolved problem. If the one set of laws 



