THE NEWTONIAN PHILOSOPHY. 529 



to put an end altogether to this mechanical phllofophy, I will go a little 

 farther in this chapter, and will endeavour to {how the faiiity, as well 

 as the dangerous tendency of that part ofSirlfaac's firft law of motion, 

 which aflerts, that body, once put in motion, will continue to move u- 

 niformly in a ftraight line, unlefs it be flopped, or its motion changed 

 by fomething external. This law of motion Des Cartes firft laid 

 down, by which he has made a machine of the whole univerle ; and 

 it has been adopted by Sir ifaac, in order to make a machine of the 

 heavens, and a machine of a moft extraordinary kind, of which there 

 is no other example in art or nature ; for all other machines that we 

 know are moved by the conftant agency of the moving ^ ower ; 

 whereas, both Des Cartes and Sir Ifaac's machines continue to be 

 moved after the moving power has ceaied to a£t. 



This is that original impreffed motion which Dr Clarke, in the paf- 

 fage I have quoted above, rejeds, in the great motions of the uni- 

 verfe. And it was the authority of fo great a fcholar and philoio- 

 pher that firft difpofed me to call in queftion this maxim, which I 

 before fubmitted to as an axiom that could not be difputed, not having 

 any propenfity to differ from opinions generally received, unlefs I fee 

 a very good reafon for it. And 1 was the lefs inclined to deny the 

 truth of the propofition altogether, that Dr Clarke, as I have obferved, 

 admits it, though he fays it does not apply to the motions of the cc- 

 leftial bodies. But, for the fame reafon, that it does not apply to 

 them, I am convinced, upon mature confideration, that it does not ap- 

 ply to any thing in nature, and is not only falfe, but tending, in its 

 confequences, towards abfolute materialifm, though, I am perfuaded, 

 that Sir Ifaac had no luch thing in view, whatever Des Cartes might 

 have had. 



This whole law of motion, as enunciated by Sir Ifaac, is as follows : 

 ' All bodies perfevcre in their ftate, whether of reft or of motion, 



X X X * uni- 



