396 ANTIENT METAPHYSICS. Book V. 



the Bodies upon thofe Planets may be of natures very different from 

 the Bodies here, and Laws of Nature may obtain there very diffcr- 

 •cnt from thofe which obtain here. 



Fyrther, this argument, from the Motion of Bodies here, would 

 have more fhow of reafon, if there was no. other Motion on this our 

 Earth except Gravitation, But there are feveral other kinds of Mo- 

 tion here, fuch as that of Fire, which is the diredl oppofite to Gravi- 

 tation ; for it is not to the centre, hut from the centre : And there 

 are Bodies, which, fo far from attradling one another, repel one an- 

 other. Now, what reafon from analogy is there to choofe one of 

 thefe Motions, more than another, and to fuppofe that our Earth is 

 moved in that way, with refpedt to the Sun ? I do not know but 

 the Gentleman at Geneva, who, I am told, is writing a Syftem of 

 Aftronomy upon the principles of Rcpulfion, inftcad of Attradion, 

 proceeds upon as probable grounds. 



And here I think the argument from Final Caufes may be very well 

 urged againfi: this hypothefis. This way of arguing, as I have elfe- 

 where obferved, is not to be admitted againft fad;s, which are either 

 certain, or very probable. But, when a fadt is laid down, that is 

 neither one nor other, I think we are entitled to deny it, unlefs the 

 perfon who avers It can affign fome good reafon why it fhould be. 

 In the cafe of Projediles, the reafon is evident why all Bodies here 

 on earth fhould have that tendency : For, otherwife, neither the bu- 

 fmefs of Nature nor of Art could be carried on; and the whole order 

 and oeconomy of things below mufl: be altered. Whereas, no reafon, 

 •which I can think of, can be devifed, for the Planets having that ten- 

 dency towards the Sun, If, indeed, it could be fhown that, without 

 fuch tendency, they could not defcribe their Elliptical Orbits round 

 the Sun, that would be a reafon unanfwerable. But, I hope I have 

 clearly Ihown that not to be the cafe ; And, if fo, the only confe- 



quence, 



