8 , COS3IOS. 



aud distinct evidence will always appear where the laws 

 of phenomena admit of being referred to mathematical prin- 

 ciples of explanation. Physical cosmography constitutes 

 merely in some of its parts a cosmology. The two expres- 

 sions cannot yet be regarded as identical. The great and 

 solemn spirit that pervades the intellectual labour, of which 

 the limits are here denned, arises from the sublime conscious- 

 ness of striving towards the infinite, and of grasping all that is 

 revealed to us amid the boundless and inexhaustible fulness 

 of creation, development, and being. 



This active striving which has existed in all ages, must 

 'frequently and under various forms, have deluded men into the 

 idea, that they had reached the goal, and discovered the prin- 

 ciple which could explain all that is variable in the organic 



vol. of this work (p. 694), on the relation borne by Newton 

 to Kepler^ cannot, I think, leave a doubt that I clearly 

 distinguish between the discovery and interpretation of 

 natural laws, i. e., the explanation of phenomena. I there 

 said of Kepler: "The rich abundance of accurate observations 

 furnished by Tycho Brahe, the zealous opponent of the 

 Copernican system, laid the foundation for the discovery 

 of those eternal laws of the planetary movements which 

 prepared imperishable renown for the name of Kepler, and 

 which, interpreted by Newton, and proved to be theoretically 

 and necessarily true, have been transferred into the bright 

 and glorious domain of thought, as the intellectual recognition 

 of nature:' Of Newton, I said (p. 736): "We close it 

 [the great epoch of Galileo, Kepler, Newton, and Leibnitz,] 

 with the figure of the earth as it was then recognized from 

 theoretical conclusions. Newton was enabled to give an 

 explanation of the system of the universe, because he suc- 

 ceeded in discovering the force from whose action the laws 

 of Kepler necessarily result." Compare on this subject (" On 

 Laws and Causes") the admirable remarks in Sir John Hers- 

 chel's address at the fifteenth meeting of the British Associa- 

 tion at Cambridge, 1845, p. xlii.; and Edinb. Rev. vol. 87, 

 1848, pp. 180-183. 



