20 INTRODUCTORY 



question whether Life should be considered as 

 an impulse a special energy which acts upon 

 Matter, or as the resultant of a particular com- 

 pound of Matter whether, in short, Life creates 

 protoplasm or is created by it. Apart from this 

 nitrogenous substance, Life does not occur ; but 

 the composition of protoplasm is by no means 

 uniform, and those who assert that it must be the 

 origin of Life may be mistaking a necessary 

 condition for an essential cause. We speak of 

 a current of electricity as " generated " by 

 chemical action; but we do not mean that, 

 apart from this action, electricity is non-existent. 

 To give a homely illustration of the difference 

 between a condition and a cause : I cannot go 

 out unless I find my boots, but I do not go out 

 because I find them. We have, it may be repeated, 

 no direct knowledge of Life : in itself it lies beyond 

 the field of our sensations. The view that is taken 

 of its nature may, then, depend very greatly upon 

 the predilections of the philosopher : if he is 

 inclined towards a mechanical theory of the 

 Universe he may be discomposed by the eccentri- 

 cities of Life, but will endeavour to explain them 

 as the inevitable, although complicated, results 

 of mechanical causes. 



There is, however, an argument, derived from 

 our observations of the manifestations of Life, 

 which appears to tell strongly against these materi- 

 alistic conclusions. If Life is the result of Matter 

 we should not expect it capriciously to disregard 

 the tendency to uniformity which enables us to cal- 

 culate the sequences of material phenomena, and 

 even to make quantitative estimates of the things 

 which underlie them. But Life seems to delight in 

 displaying its indifference to rule. It provides 

 animals with special organs for particular pur- 

 poses for instance, with eyes for seeing, with 



