94 ESSAYS AND OBSERVATIONS 



ly momentary, when they everywhere ap- 

 pear to be fo permanent? When motion 

 is begun in any body, we attribute it to 

 a certain action which we cannot pofTi- 

 bly explain ; when a body continues in 

 the motion which it has once received; it 

 appears to be a neceiTary coniequence of 

 that action. We commonly indeed fay, 

 that the body then moves on of ititlf j 

 but the only (jueftion in debate is, Whe- 

 ther there be occalion for a continual re- 

 cruit of force, new impreilions, new folli- 

 citations to motion, like to what were at 

 firft exerted by the moving power ? 



Unless this account of the continu- 

 ation of motion can be fliewn to involve, 

 fome abfurdity, why fhould we feek for 

 any other caufe of it, than the force im- 

 prefTed by the external agent r We may 

 be told perhaps, " That motion is a con- 

 " tinued adlion ;" and therefore body con- 

 tinuing to move, is adive. But is not 

 this either a begging of the queftion, or 

 taking hold of the ambiguity of language 

 to fupport it ; inftead of explaining, vrhj 

 a motion once excited fhould ceafe of it- 



felf? 



