46 EVOLUTION 



world to the * Danvinian theory.' Before Darwin, many 

 men of science were evolutionists : after Darwin, all men of 

 science became so at once, and the rest of the world is 

 rapidly preparing to follow their leadership. 



As applied to life, then, the evolutionary idea is briefly 

 this — that plants and animals have all a natural origin 

 from a single primitive living creature, which itself was 

 the product of light and heat acting on the special chemical 

 constituents of an ancient ocean. Starting from that single 

 early form, they have gone on developing ever since, from 

 the homogeneous to the heterogeneous, assuming ever more 

 varied shapes, till at last they have reached their present 

 enormous variety of tree, and shrub, and herb, and seaweed, 

 of beast, and bird, and fish, and creeping insect. Evolution 

 throughout has been one and continuous, from nebula to 

 sun, from gas-cloud to planet, from early jelly-speck to man 

 or elephant. So at least evolutionists say — and of course 

 they ought to know most about it. 



But evolution, according to the evolutionists, does not 

 even stop here. Psychology as well as biology has also its 

 evolutionary explanation : mind is concerned as truly as 

 matter. If the bodies of animals are evolved, their minds 

 must be evolved likewise. Herbert Spencer and his 

 followers have been mainly instrumentoi in elucidating 

 this aspect of the case. They have shown, or they have 

 tried to show (for I don't want to dogmatise oritlie subject), 

 how mind is gradually built up from the snnplest raw 

 elements of sense and feeling ; how emotions and intellect 

 slowly arise ; how the action of the environment on the 

 organism begets a nervous system of ever greater and 

 greater complexity, culminating at last in the brain of a 

 Newton, a Shakespeare, or a Mendelssohn. Step by step, 

 nerves have built themselves up out of the soft tissues as 

 channels of communication between part and part. Sense- 



