1 86 HOLISM AND EVOLUTION chap. 



meant a greater difference for human thought and action 

 than any other single thinker. But even he is not final. 

 He even less than Newton is final. He has pointed the 

 great way, and on that way we are already travelling beyond 

 his great vision. 



Let me first state Darwin's law, which was just as simple 

 as Newton's, and much more easily intelligible. Among 

 living beings there is a tendency to vary and over-multiply; 

 in consequence, a struggle for survival becomes inevitable, 

 and in this struggle for existence the fittest survive. This 

 explains the origin of species and all organic differences in 

 the world. The tendency to variations is a fact patent to 

 everyone; so is the over-multiplication of individuals under 

 favourable conditions and in the absence of external 

 restraints; the resulting struggle which Darwin calls 

 Natural Selection is well known to everyone who has the 

 least knowledge of animate Nature. These are the simple 

 bricks of fact with which the Darwinian theory is con- 

 structed. Surely as striking a case of Columbus' egg as 

 was ever presented. The genius of the Master was shown 

 by the vastness of the structure he produced from these 

 simple materials of common-sense and common experience. 

 From these simple commonplace facts he explained the 

 infinite variety of the forms of life which occupy the earth, 

 their geographical distribution both in the past and in the 

 present over the face of the globe, and the marvellous close- 

 ness of their adaptation to the physical and other conditions 

 among which they live — adaptation to land and sea, to 

 fresh and to salt water, to conditions of soil and climate 

 embracing the extremes of heat and cold, to the widest 

 range of wet, arid and desert conditions, and to all the 

 innumerable facts and situations which lead to the inter- 

 weaving of the mysterious web of life. 



The whole Darwinian theory is summarised in the last 

 sentences of the Origin of Species with a simplicity 

 and beauty of statement worthy of the simple but pro- 

 found genius of the Master, and they raise before us 

 in a few touches the great Darwinian vision. They have 



