Natural Selection 275 



Chambers, whose " Vestiges of Creation " remained anonymous 

 until after his death, strongly pressed the view that new 

 species of animals were being evolved from simpler types. 



During the incubatory period of Darwin's great work, as 

 Alfred Newton has remarked, systematists, both in zoology 

 and botany, had been feeling great searchings of heart as 

 to the immutability of species. There was a general feeling 

 in the air that some light on this subject would shortly appear. 

 As a recent writer has reminded us, 



" in studying the history of evolutionary ideas, we 

 must keep in mind two distinct lines of thought, first, 

 the conviction that species are not immutable, and that 

 by some means or other new forms of life are derived 

 from pre-existing ones. Secondly, the conception of some 

 process or processes by which this change of old forms and 

 new ones may be explained." 



Now, as we have seen, the first of these lines of thought 

 had been accepted by many writers. Darwin's great merit 

 was that he conceived a process by means of which this 

 evolution in the organic kingdom could be explained. 



It has been somewhat shallowly said, said in fact on the 

 day of the centenary of Darwin's birth, that " we are upon 

 very unsafe ground when we speculate upon the manner in 

 which organic evolution has proceeded without knowing 

 in the least what was the variable organic basis from which 

 the whole process started." Such statements show a certain 

 misconception, not confined to the layman, as to the scope 

 and limitations of scientific theories in general, and to the 

 theory of organic evolution in particular. The idea that 

 it is fruitless to speculate about the evolution of species 

 without determining the origin of life is based on an erroneous 

 conception of the true nature of scientific thought and of the 

 methods of scientific procedure. For Science, the world of 

 natural phenomena is a complex of procedure going on in 

 time, and the sole function of Natural Science is to construct 

 systematic schemes forming conceptual descriptions of 

 actually observed processes. Of ultimate origins Natural 

 Science has no knowledge and can give no account. The 

 question whether living matter is continuous or not with 

 what we call non-living matter is certainly one to which an 



S 2 



