xii.] THE METAPHYSICS OF SENSATION. 289 



Anthony Collins, Toland, Tinclal, "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 " Principes 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 govern 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 

 nature are expressible in terms of matter and motion. 



" Would that the rest, of the phenomena of nature 

 could be deduced by a like kind of reasoning from 

 mechanical principles. For many circumstances lead me 

 to suspect that all these phenomena may depend upon 

 certain forces, in virtue of which the particles of bodies, 

 by causes not yet known, are either mutually impelled 

 against one another and cohere into regular figures, or 

 repel and recede from one another ; which forces being 

 unknown, philosophers have as yet explored nature 

 in vain. But I hope that, either by this method of 

 philosophizing, or by some other and better, the prin- 

 ciples here laid down may throw some light upon the 

 matter." 1 



But the doctrine that all the phenomena of nature 

 are resolvable into mechanism is what people have 



1 " Utinam csotera naturae phenomena ex principiis mechanicis, eodera argu- 

 mentandi genere, derivare licet. Nam multa me mo vent, ut nonnihil suspicer 

 ea omnia ex viribus quibusdain pendere posse, quibus corporum particulae, per 

 causas nondum cognitas, vel in se mutuo impelluntur et secundum figuras regu- 

 lares cohserent vel ab kivicem fugantur et recedunt ; quibus viribus ignotis, 

 Pkilosophi hactenus Naturam frustra tentarunt. Spero autem qu6d vel huic 

 philosopliandi modo, vel veriori; alicui, principia hie posita lucem aliquam prae- 

 bebunt," Preface to First Edition of Principia, May 8, 1686. 



