What are Animals and Plants f 369 



action, using that term in a wide analogical sense. But truly 

 instinctive actions take place in us at the dawn of life. It is 

 by the aid of such alone that the infant lives. Instinctive 

 also are many of the phenomena of adolescence and those of 

 the earlier years of our own race — for no one can maintain 

 that the first beginnings of Hterature, art, science, or politics 

 were ever deliberately invented. 



How, then, are we to regard that great world of living 

 creatures, both the lower and the higher members of which 

 present phenomena so different from anything to be found in 

 the whole inorganic world ? Are, or are not, the bodies of 

 animals and plants vehicles for the exhibition of some force 

 or energy radically different from any to be found in the non- 

 living world about them, or are aU their actions to be re- 

 garded as only the very curious activities of very complex 

 machines, moved by no other power than such as are in- 

 herent in the inanimate matters of this planet ? Are we, 

 in a word, to accept a merely mechanical explanation of the 

 universe, or must we demand something more, and if so, what ? 



To many of our readers it may seem altogether absurd to 

 attempt to explain the phenomena of life in terms of the 

 movements of sohd particles. Their common-sense revolts at 

 such an explanation, but ' common-sense ' cannot be allowed 

 by itself to decide any question when an appeal has once 

 been made to the higher tribunal of pure reason, and such an 

 appeal has been made. 



For there can be no question but that a thoroughly 

 mechanical conception of nature is the scientific ideal of a 

 very large and a very influential school of thinkers, and is 

 the goal towards which they strive — following the footsteps 

 of their great predecessor Descartes. Thus, as we have 

 elsewhere noted,^ Kirchhoff tells us that ' the highest object 

 at which the natural sciences are constrained to aim is the 



I 



1 See ante. p. 338. 

 VOL. II. 2 A 



