Chap. V. ANTIENT METAPHYSICS. 393 



Motion muft neceflarily be combined one way or another. But, I 

 think, I have fhown very evidently, that this Axiom of theirs can 

 only apply to Motion produced by Bodily Impulfe, not to Motion 

 by Mind, of which only we are fpeaking at prefent. We muft, 

 therefore, feek fome reafon for this ftrange combination of Motion, 

 other than that it is neceflary for fupporting the Newtonian fyftem of 

 Aftronomy, which, if it were true, as I hope to fhow it is not, would 

 certainly not be a good reafon. 



And the more extraordinary fuch a compofition of Motion is, the 

 ftronger the reafons fhould be to fupport it. Indeed, the reafons 

 ought to be the moft forcible imaginable, to convince any man of 

 common fenfe, though not a philofopher, that two Minds of the 

 fame kind, that is, Minds which only move, fhould animate the 

 fame Body, and that thefe Minds, which, though not intelligent 

 themfelves, muft be fuppofed to be under the direction of Supreme 

 Intelligence, fhould a£t againft one another, and fhould both be em- 

 ployed to perform a Motion that might be performed by one of them. 



The only anfwer, that I have ever heard made to this argument, is, 

 by denying that the Circular or Elliptical Motion can be produced 

 from one power ; but that the Motion being compounded of two 

 Motions, one toivards the centre, and the other yrw« it, there muft 

 necefTarily be two Powers employed to produce thefe two Mo- 

 tions. 



In anfwer to this argument I have faid a good deal, more perhaps 

 than enough, in the Firft Volume * ; and I fhall now only add here, 

 that, if the Motion be compounded, the figure defcribed by it muft 

 alfo neceflarily be compounded. Now, this is a geometrical theorem, 

 which, if true, could certainly be demonftrated : But it never has 

 been demonftrated, nor ever will. And, if it fhould, Euclid muft be 

 in a miftake, who has' defined a circle to be a flam figure^ contained 



D d d under 



* Appendix, chap. 3. p. 515;. 



