THE NEWTONIAN PHILOSOPHY. 545 



belief (and I am perfuaded very fincerely) in the exiftence of an Im- 

 material being, the author of the univerfe : But, when we look into 

 the fyftem to which the Scholium is annexed, we find that, however 

 pure his theology may be, his phyftology is altogether material and 

 mechanical ; for there is not a word of Mind from the beginning of 

 the Principia to the end of it. He has fald nothing, as I have obfer- 

 ved, in his Principia, of the caufe of gravitation ; but it is evident, 

 from the account he gives of the manner of its operating, that he fup- 

 pofes it to be produced by bodily impulfe conftantly repeated : As to 

 the projedile force, whatever his followers may fay, it is evident, from 

 the name he gives it, of i;ij imprejj'a^ that he fuppofed it to be a force 

 external ading..upon the furface of the body, not internally, and up- 

 on every particle of the body, in the manner that Dr Clarke fup- 

 pofes Mind to move body. The projedile force, therefore, is the 

 operation of body upon body : And, accordingly, the continuance 

 of the projedile motion, after the impulfe which produced it has 

 ceafed, is grounded upon Sir Ifaac's firft law of motion, which is 

 derived from the obfervation of the effedt of the Impulfe of body 

 upon body here on earth. All the great motions, therefore, in the 

 univerfe are produced, according to Sir Ifaac, by bodily impulfe. 

 And even animal motion, and fenfation, are produced, he fays, in 

 the fame manner : For, if matter be the caufe of them, though fo 

 fubtile, as to be called, by Sir Ifaac, fpirit^ they muft be produced 

 by impulfe likewife j fmce matter, as 1 have fhown, cannot other- 

 wife a6t upon matter. And, even In his lafl: thoughts upon the fub- 

 je<3:, 1 mean the Queries fubjolned to his Optics, he does not fpeak 

 of Mind as producing any motion, though he mentions an adive 

 principle in matter, to which he there afcrlbes all the motions In 

 the univerfe. It is, therefore, evident to me, that Sir Ifaac had no 

 conception how .motion could be produced othcrwife than by impulfe, 

 that is, by body moving body, and therefore proceeded upon the no- 

 tion that the celeftial bodies were moved by other bodies, which con- 

 fequently muft themfelves have been moved. His example fhows 

 how neceffary it is that thofe who carry their fpeculations be- 



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