THEORY OF CATASTROPHES. 77 



been just as different at every period as were the animals 

 and plants then inhabiting it. Combining this view with the 

 results of his own palaeontological and zoological researches, 

 and striving to understand clearly the whole course of the 

 evolution of Creation, Cuvier arrived at the hypothesis 

 usually called the Theory of Cataclysms or Catastrophes, or 

 the Doctrine of Violent Upheavals. According to it several 

 revolutions occurred on our earth at certain times, suddenly 

 destroying every living inhabitant ; and at the end of each 

 of these catastrophes an entirely new creation of organisms 

 took place. But as the latter cannot be conceived as 

 having been effected wholly by natural means, we must 

 suppose, in explanation, that the Creator supernaturally 

 interfered in the natural course of things. This Doctrine of 

 Revolutions, treated by Cuvier in a separate work, which 

 has been translated into several modern languages, was 

 soon generally accepted, and for half a century continued 

 to prevail among biologists ; there are even yet a few 

 prominent naturalists who advocate it. 



It is true that more than forty years ago Cuvier's 

 Doctrine of Catastrophes was altogether renounced by 

 geologists ; and first of all by the English geologist, Charles 

 Lyell, the most important authority in this branch of 

 natural science. As early as the year 1830, in his famous 

 "Principles of Geology," he proved that that doctrine is 

 utterly false so far as the crust of the earth itself is con- 

 cerned ; and he showed that in order to explain the structure 

 and evolution of mountains, there is no need of having re- 

 course to supernatural causes or universal catastrophes. On 

 the contrary, the ordinary causes which even now unceasingly 

 effect the transformation and reconstruction of the earth, are 



