84 Thomas Henry Huxley 



interaction of causes which had brought the world into 

 its present condition. He gave a striking display of 

 the wide knowledge of his reading by going back to 

 the foundation of this branch of modern science, and 

 giving a masterly account of the then little-known 

 treatise of Inimanuel Kant, who in 1775 had written 

 A/i Attempt to Account for the Constitutional and 

 Mechanical Origin of the Universe upon Nezvtonian 

 Principles. Next he declared that evolution embraced 

 all that was sound in both catastrophism and uniform- 

 itarianism while rejecting the arbitrary limits and 

 assumptions of both. 



Finally he came to the great question to which these 

 observations upon the existing schools of geology had 

 led. The most distinguished physicist of the age, then 

 Sir William Thomson, now L,ord Kelvin, and Huxley's 

 immediate successor in the Presidential Chair of the 

 Royal Society, had stated that the English school of 

 geology had assumed an impossible age for the earth. 

 By physical reasonings, Thomson stated that he was 

 able to prove " That the existing state of things on the 

 earth — all geological history showing continuity of life 

 — must be limited within some such period of time as 

 one hundred million years." This pronouncement had 

 been received wnth acclamation by those who feared the 

 geological and biological sciences, as a sign of internal 

 dissensions within the house of science. Huxley, then, 

 as all through the latter part of his life, at once con- 

 stituted himself the champion of science, and, taking 

 Thomson's arguments one by one, shewed by a series 

 of masterly deductions from known facts that there was 

 a great deal to be said for the other side, and that phy- 

 sicists were as little certain as geologists could be of the 

 exact duration of time that had elapsed since the dawn 



