188 A MODEL OF NATURE. 



THE PHENOMENA OF LIFE. 



But it may be asked- -nay, it has been asked — may not the type of 

 our theories be radically changed ? If this question does not merely 

 imply a certain distrust in our own powers of reasoning, it should be 

 supported by some indication of the kind of change which is conceivable. 



Perhaps the chief objection which can be brought against physical 

 theories is that they deal only with the inanimate side of nature, and 

 largel} ignore the phenomena of life. It is therefore in this direction, 

 if in any. that a change of type may be expected. I do not propose to 

 enter at length upon so difficult a question, but, however we may 

 explain or explain away the characteristics of life, the argument for 

 the truth of the atomic theory would only be affected if it could be 

 shown that living matter does not possess the thermal and mechanical 

 properties, to explain which the atomic theory has been framed. This 

 is so notoriously not the case that there is the gravest doubt whether 

 life can in any way interfere with the action within the organism 

 of the laws of matter in bulk belonging to the domain of mechanics, 

 physics, and chemistry. 



Probably the most cautious opinion that could now be expressed on 

 this question is that, in spite of some outstanding difficulties which have 

 recently given rise to what is called Neovitalism, there is no conclusive 

 evidence that living matter can suspend or modify any of the natural 

 laws which would affect it if it were to cease to live. It is possible 

 that though subject to these laws the organism while living may be able 

 to employ, or even to direct, their action within itself for its own 

 benefit, just as it unquestionably does make use of the processes of 

 external nature for its own purposes. But if this be so, the seat of 

 the controlling influence is so withdrawn from view that on the one 

 hand its very existence may be denied, while on the other hand, Pro- 

 fessor Haeckel, following Vogt, has recently asserted that "Matter 

 and ether are not dead, and only moved by extrinsic force; but the}'' 

 are endowed with sensation and will; they experience an inclination 

 for condensation, a dislike for strain: they strive after the one and 

 struggle against the other."" 



But neither unproved assertions of this kind nor the more refined 

 attempts that have been made by others to bring the phenomena of 

 life and of dead matter under a common formula touch the evidence 

 for the atomic theory. The question as to whether matter consists of 

 elements capable of independent motion is prior to and independent of 

 the further questions as to what these elements are and whether they 

 are alive or dead. 



The physicist, it' he keeps to his business, asserts, as the bases of 

 the atomic theory, nothing more than that he who declines to admit 

 that matter consists of separate moving parts must regard many of 



* Riddle of the Universe (English translation), 1900, p. 380. 



