Chap. in. A N T I E N T METAPHYSICS. :i6s 



merely for the fake of argument and contradiction to received opi- 

 nions, but is founded upon fa(^ and obfervation, and the analogy of 

 other Motions in Nature.^ 



If it be admitted that the Motion of the Projedile is carried on by 

 Mind, and not by Body or Bodily Impulfe, I think it is of little 

 confequence how long that Motion is to laft, concerning which we 

 are only fure of one thing, that it will laft as long, and no longer, 

 than the bufinefs of Nature requires : And another thing we may 

 venture to affirm, that, when it flops, it will not flop at once, but 

 languilh and decay by degrees ; for there is a progrefs of every thing 

 in Nature, and particularly of the Movements of Mind in Body. 

 That this A'lotion is, by its nature, eternal here on earth, if there 

 were no obftacle in its way, or no power to countcrad it, I cannot 

 believe. It never can be proved by fad: or experiment j and there- 

 fore it is not to be believed, unlefs a good reafon could be affigned 

 why it fhould be fo. For, though I do not admit the argument 

 from final caufes, againft the exiflence of a thing which is proved by 

 fad and experience to exifl, I think we may very well argue in that 

 way againft the fuppofition of a fad which is neither proved nor 

 probable. As, therefore, in this cafe, no reafon can be given for 

 the eternity of fuch a Motion ; I think, to fuppofe it, is mere hypo- 

 thefis. I therefore hold that the Mind which moves the Body im- 

 pelled does not flop it ; for that would be to fuppofe that it would 

 otherwife, and by its own nature, continue in Motion; but it exerts 

 lefs and lefs its Motive Power, till at laft it does not exert at all, and 

 then the Motion ceafes, like all other Motions produced by Mind. 

 This Motion, therefore, according to my hypothefis, grows flower 

 and flower by degrees, till at laft the Body ftands ftill : But the 

 more violent the impulfe, the longer the Motion continues ; and its 

 velocity is likewife greater at firft, which no doubt is diminifhed by 

 the rcfiftence of the Medium, but it is alfo diminiflied by the lefs 



exertion 



