Qiap.IX. ANTIENT METAPHYSICS. 455 



fame Moving Power, that is, Body, to produce the Motion, but 

 alfo that Power ading in the fame way, that is, by Pulfion. 



The lafl: pofTible cafe upon this Hypothefis is, that the Planets 

 fhould be moved in the one Line, by PuIfion, and, in the other, by 

 Trufion ; for, as to its being moved by Drawing * in either of the 

 Lines, it is fuppofed, I behevc, by nobody. This Syftem has not the 

 unifonnity of the kift meutioned ; for, though it employ the fame 

 Power to move the Planet, that Po^.er operates differently in each of 

 the. Motions. 



I come now to the fourth and laft H)'pothefis, which fuppofes the. 

 Planet to be moved both by Mind and Body. The common way of 

 dividing the Motion, thus compounded of thefc different Powers is 

 to fuppofe that the Projedile Motion is from Bodily Impulfe, but 

 the Centripetal Motion by Mind. But here, too, there is a confi- 

 derable variety of poffible cafes; for the Projedile Motion may be 

 fuppofed to be produced, either by Pulfion or by Trufion, and if 

 by Impulfe,. either by one PulHvtion, or by repeated Puliations : 

 Or, the Hypothefis may be changed with refpedl to the two Motions 

 and the Centripetal Motion may be fuppofed to be produced by Body • 

 and this in two ways, either by Pulfion, or by Trufion while the 

 Projedile Motion is carried on by Mind ; and this, by Mind ading 

 either by one Impulfe, as Body ads, or by conftant and unceafing 

 energy. 



Thefe are all the poffible ways in which the Planets can be mo- 

 ved ; fo many, and fo various, that, I am afraid, I have wearied 



my 



* Drawing, as I have explained if, p. 343. is, when the Moving Force aflj 

 upon that part of the Body which is next to the dircaion in which- the Body is 

 cd, not upon the oppofite fide ; for then it is Protruft^n, not Drawing, 



mov 



