Chap. T. APPENDIX. 289 



wifdom and power, being fucli that it difordered itfelf, and there- 

 fore needed the mending hand of the artificer from time to 

 time *. 



The later interpreters of Sir Ifaac's phiiofophy have thought 

 that they improved it by fuppofing that one of the Motions, viz. 

 the Centripetal, was produced by the conftant agency of Mind. 

 But, whether they have really improved Sir Ifaac's fyftem by ma- 

 king the Planetary Motion fo much m.ore complicated, as that two 

 parts of three of it (I mean the Projed:ile Motion by which the 

 Planet is carried on in its orbit, and its Motion round its centre,) 

 are mechanical, and the third, that is, the Centripetal Motion, by 

 Mind, may, I think, with good reafon, be doubted t. But, be that 

 as it will, there is one thing, in which I underftand that all the New- 

 tonians are at prefent agreed, (unlefs, perhaps, fome few of them, 

 that are philofophers as well as mathematicians, fuch as Dr Horfley 

 is, and Dr Clarke wasj, that the ProgrelTive Motion of the Planet 

 goes on by virtue of an original impulfe, in confequence of Sir I- 

 faac's firft law of Motion. And the only queftion among them is, 

 whether this be the effect of the original impulfe alone ? Or whether 

 there be not alfo a 'uis injita, or poiver inherent in the body, and 

 eflential to it, by which the Motion has been carried on for fo many 

 thoufand years after the original impulfe had ceafed ? 



When I wrote my fecond volume, the Newtonians, with whom I 

 liad converfed and correfponded, were unwilling to allow that Mat- 

 ter had any fuch Power in itfelf, by which it could carry on Mo- 

 tion without any agency either of Mind or of other Bodies ; and 

 therefore they fuppofed that the continuance of the Motion was the 

 Vol. III. O effed 



* Vol. ii. p. 329. 

 t Vol. ii. p. 331. 



