THE DOGMA OF EVOLUTION 



in a man who is engaged in a difficult philosophical 

 problem not to be able to comprehend philosophical 

 thinking; the virtue lies merely in the recognition of 

 such inability. 



Darwin, himself, attempted only once to invade 

 the field of philosophy. Although he usually admitted 

 an unknown principle of variation, he advanced an 

 hypothesis to account for heredity by what he called 

 pangenesis. In brief, his idea was that each cell of an 

 individual contributes minute particles, pangenes or 

 gemmules, to the reproductive organs so that each 

 ovum or sperm contains within itself all the distin- 

 guishing features of its parent body. There is hardly 

 any need to discuss it, as pangenesis obviously was so 

 improbable that it never lived except in the affection 

 of its author. Huxley immediately saw the futility of 

 the idea and begged Darwin not to emphasize it, lest 

 such an explanation of evolution by natural selec- 

 tion would lower the probability of the larger theo- 

 ry and retard the great work of its acceptance; but 

 Darwin clung to pangenesis with the blind affection 

 of a parent for a defective child. In the first place, we 

 have never had the slightest evidence that the organic 

 cell does detach from itself such a part as a gemmule. 

 In the next place, such a gemmule must be potentially 

 the same as its parent cell, and we are left to explain 

 the gemmule; we have merely changed the organism 

 from an aggregation of cells to one of gemmules ; we 

 should, to say the least, have some difficulty in find- 



