Chap. XIX. A N T I E N T METAPHYSICS. - r^ 



Sir Ifaac's aHironomy fappofes, that the power of gravitation, by 

 ^hich bodies tend towards fome center, extends through the whole 

 univerfe, at leaft, through all our fyftem. ' This power,* fays Sir 

 Ifaac, * I do not affirm to be effential to matter, or inherent in its na- 



* ture-^* I wifh he had faid the thing more ftrongly, and had affirmed 

 pofitively, ' That a power of moving itfelf was not eiTential to rnat- 



* ter ;* as evevy body v;ho fays the contrary is plainly an AtheiH;, in 

 confequence of that principle, whether he knows it or not. The New^ 

 tonians, therefore, to avoid that imputation, muft admit, that the 

 motion of gravitation is- from nriirid, " mediately or immediately, as 

 well as the projedile motion of the planets ; and, as their phiiofophy 

 does not fuppofe that the Deity acts indefinently upon matter^ far 

 lefs that there is any mind, or internal principle, ading conflantly 

 upon body, they, muft needs fuppofe, that gravitation, as v-ell as the 

 projedile motion, is produced by one. impulfe given by the Deity, and' 

 which (till continues to operate with undiminifhed force. But this, 

 as I have faid, is mere hypothefis, not at all neceflary, nor even pro- 

 bable. It might have been faid to be neceffary, if we could hare dlf- 

 covered no other- natural inovement in body, except a tendency to- 

 wards a center ; but^ as there are io many other natural movements ia 

 body, one diredtly oppofite to this, it is far from being ncceifary to. 

 fuppofe this fingle movement to be univerlal in Nature; and, not 

 only it is not rieceifary, but it is very ii!>probable, when weconfidcr,. 

 that animals here qn earth perforin fuch motions as ihofe ot the planets,. 

 tho' not conftantly, but occalionally, nor with the Tame regularity, as 

 may be well fuppofed. Why, then, ought we nut to believe, that the 

 heavenly bodies perform the tame motion, animaied by the Ian. c principle 

 — -w/?W, and even intelligaice, as the antient philol ph. I!^ lappo.cu ? u 

 is a comn>on way of arguing among the Newioniai.s, that, where wc 

 fee the fame effeds produced, we are to luppolc the iauic caule. JNow, 



K k the 



* Gravitatem corporihus effentiatem efle, minime affirmo. Piinclpia Mathcmaticafi 

 ziol. 3. Regula Philofophandi ^tia* 



