PHYSICAL AND LITERARY. r<? 



to the inertnefs and paffive nature of mat • 

 ter, andconfiderthe prefent ftate of a piec-e 

 -of matter, whether of motion or of reft, to 

 be an efFed:, which, once produced, mull 

 continue to exift as it is, till it be changed or 

 deftroyed by the operation of a new caufe. 

 But, as this conception of the matter is 

 liable to iT:rong objedlions, which fliall by 

 and by be mentioned, the moft rational 

 writers admit of a power in matter to 

 preferve itfelf in its prefent ftate ; but 

 then, confidering the perfeverence in reft and 

 in motion to be eSeds of the fame kind, 

 they, without making any diftincflion, 

 attribute both to the fame power or caufe, 

 I cannot fubfcribe to either of thefe no- 

 tions. It is obvious to me, that the 

 mere negation of a caufe, though it may 

 account for the continuance of a body at 

 reft, as it may account for its preferving 

 the fame figure or colour ; yet can never 

 account for the refiftance made in the 

 change from reft to motion, or from mo- 

 tion to reft. And it is equally obvious, 

 that a ftate of motion is very different 

 from a ftate of reft; and that the prefer- 



