i66 PROGRESS OF SCIENCE. 



the evolutionary principle into geology, instead of the sudden 

 cataclysms and new creations of former geologists, and at 

 their head Cuvier an immense stride forward. The 

 evolutionism of Lyell, however, was not that of the Spencer- 

 Darwin school for, where thorough evolutionists see an 

 efficient cause, Lyell, influenced by religious considerations, 

 saw a final cause; and the difference is, not important only, 

 but fundamental. For in the former case (in Lyell's 

 evolutionism), a supernatural power would be restraining a 

 warring chaos by a beneficent omnipresent and ubiquitous 

 interference ; whereas in the latter case, matter swayed by 

 natural laws is for ever effecting a new redistribution of its 

 elements, in harmony with its own inherent energy. The 

 evolutionary hypothesis explains the existence of evil, from 

 the presence of microbes which destroy life wholesale, to the 

 recurrence of earthquakes which destroy cities otherwise evil 

 would necessarily be prevented by the superior power. 

 METAMORPHISM, the name Lyell gave to his system of 

 gradual transformation, he based on entirely scientific ground. 

 He holds that nature has formed the crust of the earth, and 

 wrought all the successive changes, renovations, destructions 

 which it has undergone by the working of certain constant 

 and uniform laws, which are now what they ever were that 

 is, attraction, degradation, denudation, deposition, radiation, 

 evaporation, and contraction have done it all by their per- 

 manent action. This great principle of uniformitarianism, for 

 which Lyell stoutly fought, has been accepted by scientific 

 men, but, at present, with the reservation, however, that 

 variations in the energy and in the rate of activity may 

 have occurred, which played an important part in the 

 terrestrial history otherwise, how are we to account for the 

 Glacial period, which was comparatively sudden ? Physicists, 

 too, have sobered the minds of those geologists who claimed 

 a sort of "perpetual motion in the machinery of nature," to 

 use the words of Sir A. Geikie, by pointing out that the 

 gradual loss of solar heat must necessarily modify the laws 

 in future ages, and must likewise have done so in the past. 

 By a striking anomaly, Lyell, who recognised the modification 

 of the globe to be due to natural laws in fact to evolutionary 



