THE METAPHYSICS OF SENSATION 245 



inquiry, with which the people of our race are 

 naturally endowed, developed itself vigorously ; 

 and at least two of its products have had a 

 profound and a permanent influence upon the 

 subsequent course of thought in the world. The 

 one of these was English Freethinking ; the 

 other, the Theory of Gravitation. 



Looking back to the origin of the intellectual 

 impulses of which these were the results, we are 

 led to Herbert, to Hobbes, to Bacon ; and to one 

 who stands in advance of all these, as the most 

 typical man of his time Descartes. It is the 

 Cartesian doubt the maxim that assent may 

 properly be given to no propositions but such as 

 are perfectly clear and distinct which, becoming 

 incarnate, so to speak, in the Englishmen, Anthony 

 Collins, Toland, Tindal, Woolston, and in the 

 wonderful Frenchman, Pierre Bayle, reached its 

 final term in Hume. And, on the other hand, 

 although the theory of Gravitation set aside the 

 Cartesian vortices yet the spirit of the "Prin- 

 cipes de Philosophic " attained its apotheosis 

 when Newton demonstrated all the host of heaven 

 to be but the elements of a vast mechanism, 

 regulated by the same laws as those which ex- 

 press the falling of a stone to the ground. There 

 is a passage in the preface to the first edition 

 of the "Principia" which shows that Newton 

 was penetrated, as completely as Descartes, 

 with the belief that all the phenomena of 



