From Inorganic Matter to Life. 1 65 



the very property or principle to be accounted for 

 life, in assuming the production of protoplasm which 

 is a form of living matter as an intermediate step in 

 the progress towards life. The assumption is in direct 

 conflict with a quite uniform experience. 



3. But granting Mr. Spencer his "still more com- 

 posite, still more sensitive, still more variously 

 changeable portions of organic matter," we cannot 

 at once allow him that they "displayed actions 

 varying little by little into those called vital." He 

 takes for granted that by variations added by little 

 and little the actions displayed by the minute aggre- 

 gates of protein molecules would in the end reach 

 actions properly called vital. This is to take for 

 granted the very point at issue. To assume that the 

 addition of a sufficiently prolonged series of changes, 

 each in itself infinitesimal, to action which is not 

 vital, will constitute vital action, is to assume that the 

 difference between mechanical and vital action is one 

 of minute variation and not of kind. The two kinds 

 of action are altogether diverse. To assume that they 

 are similar, that they are but varieties of the same, 

 is another of the instances so frequently occurring in 

 the evolution doctrine of obliterating dividing lines 

 when they run across the doctrine and break its 

 continuity. It is the business of science not to bury 

 facts but to explain them. 



Motion internal to the aggregates called molecules 

 may be conceived as changed in many ways : it may 



