Chap. XV. ANTIENTMETAPHYSICS. 189 



as draw the attention of the vulgar : But it is not, for that, the lefs 

 wonderful in the eyes of the philofopher ; for he knows that there 

 can be no effect without a caufe, and that the caufe mud: be corre- 

 fpondent to the efFed, and of etficacy fufficient to produce it ; and that, 

 therefore, when a tower falls to the ground, perhaps in a folid mafs,or 

 when a rock, of fome thoufand tons weight, tumbles from, tht: top of 

 a mountain, carrying every thing before it that ftands in its way, 

 there muft be fome power that impells it. Now, if this power be 

 that fuppofed fluid, how prodigious muft its mafs, or its velocity, or 

 both, be, to produce fo extraordinary an effed ? and it is to be obfer- 

 ved, in the morion of thofe falling bodies, that their velocity, and, by 

 confequence, their force, always increafes, as the time of the motion 

 continues, contrary to all other mechanical motions, which decreafe, 

 and grow weaker, the longer they are continued, and the tarther 

 they are propagated or carried on ; fo that here we have an iavifible 

 fluid, ading, not only with a prodigious force, but indefinently, and 

 with an accumulating force. A philofophy of this kind does not ex- 

 plain nature, fuch as God Almighty has made it, but creates a new 

 world, and makes new laws of matter and motion. And, indeed, it is to 

 be wondered, that Sir Ifaac fhould have propofed, even as a query, 

 this caufe of motion, after he had refuted fo folidly Des Carte-'s fyftein 

 of vortices ; for Sir Uaac's fluid is liable to the fame objedions which 

 ftrike againft thofe vortices \firft^ that there is no proof of its exiftence, 

 2iX\^^f£Condlyy if it did exift, it would not anlwer the purpofe. 



This proof, from the phaenomena of nature, applies equally to mo- 

 tion ot all bodies, wheiher animate or inanimate, as they are com- 

 monly called : Nor, indeed, dv) i thmk that any diflindion can be 

 made betwixt them, as to the quellion, Whether the principle of mo- 

 tion be material or immaterial ? Though 1 know it is very common to 

 make a great diflindion, and to fay that aninial bodies are moved by 

 mind and by intention', whereas inanimate bodies are moved by 7iature, 



But 



