6 THE THEORY OF EVOLUTION 



of modern biological opinions, excepting that of the 

 strictly Darwinian school. They suffice, however, to 

 show how little support such opinions offer to those 

 who would cast aside the theory of evolution as a 

 worn-out hypothesis. It is clear that the differences 

 of belief are almost wholly concerned with the 

 problems of modes and factors, not with the theory 

 itself. The duality of meaning attached to the term 

 "Darwinism' is largely responsible for the popular 

 misapprehension as to the present status of the theory 

 among naturalists. Darwinism is frequently em- 

 ployed as synonymous with evolution, but this is an 

 inexact usage, and the term should be restricted to 

 Darwin's explanation of the evolutionary process. 

 Owing to this inaccurate use of the word, many 

 people, when they hear that such and such prominent 

 biologists have rejected and attacked Darwinism, 

 jump to the entirely false conclusion that the attack 

 is directed against the theory of development. 



The theory of organic evolution made its appear- 

 ance very early in the history of Greek philosophy 

 and reappeared from time to time in Roman and 

 mediaeval writers, because of the charm which the 

 conception of uniformity and continuity in nature 

 exercises over many minds. But these early sugges- 

 tions were merely speculative; no attempt was made 

 to support the theory by evidence, or to gather a 

 systematic body of observed facts which demanded 

 explanation. Each writer was content to quote from 

 such predecessors as appealed to his fancy or his 



