1 8 THE DOCTRINE OF DESCENT. 



the atoms, is likewise included in the incomprehensi- 

 bility of matter. 



" If we pass over this," says Dubois-Reymond again, 

 " the universe is approximately comprehensible. Even 

 the appearance on the earth of life in the abstract does 

 not render it incomprehensible. For life in the abstract, 

 contemplated from the standpoint of the theoretical 

 investigation of nature, is merely the arrangement of 

 molecules in a state of more or less stable equilibrium, 

 and the introduction of an exchange of material, partly 

 by their own elastic force, partly by motion trans- 

 ferred from without. It is a misapprehension to see 

 anything supernatural in this." 



This is the point which is usually contested with the 

 greatest vehemence. If all the motions and states of 

 quiescence of the inanimate world can be thoroughly 

 explained, the inexplicable must commence with the 

 basis of life. The imputation cast upon the reasoning 

 powers by this assumption may be formularized as 

 follows, in the question put by another sound and 

 thoughtful physiologist, A, Fick : * " Are the charac- 

 teristics of such a particle, as already explained, 

 applicable and effective during the period of its sojourn 

 in an organism ? Thus, for instance, will the motions 

 of a particle of oxygen be affected and altered by a 

 neighbouring particle of hydrogen, in accordance with 

 the same laws, when one or both form part of an 

 organism, as when they are out of it ? " 



To reply in the negative is to avow the vitalistic 

 conception of life, that is, to take refuge in unknown 

 forces quite extraneous to matter, and to admit that 

 the self-same particle can vary its nature, according 



