I 



Chap. VI. ANTIENT METAPHYSICS. 421 



though I fliould not be able, nor any the moft complete Geometer 

 or Aftronomer, to deduce thofe qualities of the Motion from its 

 nature and eirence, that would be no rcafon for making fuch ftrange 

 fuppofitions ; and it would be much better fairly to acknowledge 

 that we are not able to make a Syftem or Science of Aftronomy, 

 and fo leave it in the ftate it was in before Sir Ifaac meddled with it. 



Nor would this be anywife extraordinary; for there are many 

 things in Nature, of which we are fure that there is a Syftem and 

 a governing Principle, but which hitherto we have not been able to 

 difcover. This is the cafe of Eledlricity, and of Magnetifm, and of 

 all the phaenomena which chemiftry exhibits to us; yet, of thefe, 

 as well as of other things, every man, who believes that Supreme In- 

 telligence prefides in the univerfe, muft likewife. believe that there is. 

 a Syftem and a Science. 



But, in this cafe, I believe there is a Syftem, which Sir Ifaac has 

 difcovered ; but it is to me evident that his Syftem can be as well 

 fupported, upon the hypothejis of the Planets being moved towards 

 their Centre, as if they were aclually fo. From what I have already 

 faid, I think it is evident that it is impoflible to difcover the Mo- 

 ving Force of the Planets in their Orbits, without refolving their 

 Motion into Straight Lines. Now, this cannot be done except by 

 Hypothefis, as- their Motion is certainly not actually compofed of 

 Motions in Straight Lines ; and, if fo, there can be no hypothefis 

 more natural than the hypothefis which I make : For, in the Jirjl 

 place, the fadt is certain, that the Planets do defcend from the 

 Tangent towards their Centre ; 2^/)', It is evident that this defcent 

 Is according to the Law of falling Bodies here on Earth. Now, as 

 there is nothing in Nature without a Caufe, there muft be fome 

 Caufe producing this Defcent ; and, where the Effe£l is the fame as 

 in the cafe of falling Bodies, there is nothing more natural than to 

 fuppofe, by way of Hypothefis, the fame caufe. And the only Dif- 

 ference, 



