1 8 THE DOCTRINE OF DESCENT. 



the atoms, is likewise included in the incomprehensibil- 

 ity 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 in- 

 vestigation of nature, is merely the arrangement of mole- 

 cules 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 transferred from 

 without. It is a misapprehension to see anything super- 

 natural 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 physi- 

 ologist, A. Fick : * " Are the characteristics 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 hy- 

 drogen, 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 to 



