IX THE HISTORY AND SCOPE OF ZOOLOGY 381 



of " fiats " delivered by an anthropomorphic Creator. 

 It was not until the end of the eighteenth century 

 that Schelling (as quoted above) conceived that unity 

 of nature and general law of development which is 

 now called the doctrine of evolution. 



In England Erasmus Darwin (Zoonomia, published 

 in 1794-1796), in France Lamarck (Philosophic Zoo- 

 logique, 1809) and Geoffrey Saint-Hilaire (Principes 

 de Philosophic Zoologique, 1830), and in Germany 

 Oken (Lehrbuch der Natur- Philosophic, 1809-1811), 

 Goethe (Zur Natur Wissensch. Stuttgart, 1817), and 

 Treviranus (Biologic, 1802-1805) were the authors of 

 more or less complete systems of a philosophy of 

 nature in which living things were regarded as the 

 outcome of natural law, that is, of the same general 

 processes which had produced the inanimate universe. 

 The " Natur-philosophen," as they were called in Ger- 

 many, demand the fullest recognition and esteem. 

 But, just in proportion as the " Natur-philosophen " 

 failed to produce an immediate effect on the study of 

 Zoology 'by their theory of natural development, so 

 was the doctrine of evolution itself deprived of com- 

 pleteness and of the most important demonstration of 

 its laws by the long-continued delay in the final intro- 

 duction of Biology into the area of that doctrine. 



Darwin by his discovery of the mechanical prin- 

 ciple of organic evolution, namely, the survival of the 

 fittest in the struggle for existence, completed the 

 doctrine of evolution, and gave it that unity and 

 authority which was necessary in order that it should 

 reform the whole range of philosophy. The detailed 



