THE WORLD INTO WHICH DARWIN WAS BORN 7 



biology, had frankly and perhaps unthinkingly accepted 

 this current and almost universal dogma of the fixity and 

 immutability of species. Indeed, by defining a kind as 

 a group of plants or animals so closely resembling one 

 another as to give rise to the belief that they might all 

 be descended from a single ancestor or pair of ancestors, 

 he implicitly gave the new sanction of his weighty 

 authority to the creation hypothesis, and to the pre- 

 valent doctrine of the unchangeability of organic forms. 

 To Linnaeus, the species into which he mapped out all 

 the plants and animals then known, appeared as the 

 descendants each of a solitary progenitor or of a 

 primitive couple, called into existence at the beginning 

 of all things by the direct fiat of a designing Creator. 

 He saw the world of organic life as composed of so 

 many well-demarcated types, each separate, distinct, 

 and immutable, each capable of producing its like ad 

 infinitum, and each unable to vary from its central 

 standard in any of its individuals, except perhaps 

 within very narrow and unimportant limits. 



But towards the close of the eighteenth century, 

 side by side with the general awakening of the human 

 intellect and the arrival of a new era of free 

 social investigation, which culminated in a fresh order 

 of things, there was developed a more critical and 

 sceptical attitude in the world of science, which soon 

 produced a notable change of front among thinking 

 naturalists as to the origin and meaning of specific 

 distinctions. 



Bufibn was the first great biological innovator who 

 ventured, in very doubtful and tentative language, to 

 suggest the possibility of the rise of species from one 



