CLASSIFICATION 709 



but need not be considered further here. The second supposes 

 that at some point or points in time species have been created 

 by an immaterial god. The commonest form of the hypothesis, 

 known as special creation, supposes that existing species, as 

 we now know them, were created more or less together, and that 

 since then there has been no change beyond the limits of the 

 species. This is illustrated by the biblical story of the creation, 

 but its development as a scientific hypothesis came after the 

 reformation and is mainly the work of the eighteenth century. 

 Another form of the hypothesis, known as catastrophism, was 

 developed by Cuvier (1769-1832) to account for the fossils of 

 extinct animals found in the rocks. It supposes that there have 

 been several creations, followed by complete or partial cataclysms, 

 leading to widespread extinction of forms. 



EVOLUTION 



Theories of creation are only possible to theists, and no 

 atheist before the nineteenth century seems to have had any 

 clear idea of what he would have put in their place. Some 

 eighteenth-century writers, such as Buffon (1707-88) and 

 Erasmus Darwin (1731-1802) had hazy ideas that one species 

 might be derived from another, but it was not until the nineteenth 

 century that the third hypothesis, that of organic evolution, 

 became of any importance. It postulates that all existing species 

 are derived by descent from other species, which are in general 

 simpler in structure. Its development was largely due to the 

 writings of Alfred Russell Wallace (1823-1913) and Charles 

 Robert Darwin (1809-82) who in 1858 contributed a joint paper 

 to the Linnean Society in which they put forward the view that 

 species had evolved by a process of natural selection of those 

 races most fitted to survive in particular surroundings. Darwin's 

 Origin of Species followed in 1859. It is often said that the strength 

 of argument and wealth of illustration which Darwin employed 

 compelled belief in organic evolution. This is in part true, but 

 at least as important is the time at which he wrote. As Lecky 

 says of the history of religious thought, the success of any opinion 

 depends ' much less upon the force of its arguments, or upon 

 the ability of its advocates, than upon the predisposition of 

 society to receive it '. Darwin lived at a time when there was 

 increasing distaste among the intellectual public for believing 

 in divine interference in the affairs of the world. Evolution is 



