116 WHAT IS LIFE 



bye-products without in any way interfering with 

 its own existence or work. In the free play of 

 powers to be met within the living organism lies 

 a profound difference between it and the limited 

 capabilities of the machine. Such, in paraphrase, 

 are the views of the distinguished German biolo- 

 gist and the differences on which he insists, one 

 would have thought, would have been such as 

 would have appealed to most observers. Such, 

 however, is not the case, as we may easily see by 

 referring to the books of those who uphold the 

 Mechanical mechanical theory and how difficult it is to justify 

 tiontT tnat th eor y ma y perhaps be best seen by studying 

 the explanations of their views which have been 

 given by some of the most distinguished amongst 

 them. 



Let us examine two instances, one from the 

 writings of a living, the other from those of a 

 recently deceased writer, and we will take the 

 former first, in due order of time. Herbert 

 Spencer Spencer 1 declines to admit the existence of a nisus 

 formativus or vital force or principle, and is con- 

 fronted with the necessity of accounting for the 

 phenomena which he sees before him. How does 

 he do it ? He tells us that " the polarities of the 

 molecules determine the direction in which the 

 power (of environing forces) is turned ". l This ex- 

 1 See Principles of Biology, vol. i., App. D., p. 705. 



