40 ESSAYS AND OBSERVATIONS 



And if no facl can be condefcended on, 

 to prove the point with regard to hard 

 bodies, why ftiould we adapt this as an. 

 univerfal law of motion or of matter? 

 For furely it is irrational to admit of any 

 law or principle without evidence. 



These difficulties will be beft illuftra- 

 ted by entering upon particulars. And 

 with regard to Sir Ifaac's firft inftance, of 

 a man's preffing a (tone with his hand j 

 we mufl diftinguiih betwixt a moveable 

 and immoveable obftacle. If a man prefs 

 an immoveable obftacle with his hand, 

 I cannot here difcover any thing but mere 

 refiftance., which is not to be overcome by 

 the force of the hand. This is an efFed 

 which muft follow from the impenetra- 

 bility of matter, without neceffity of ta= 

 king under confideration any other of its 

 properties. I difcover here no readion. 

 There is no counter-adlion or impulfe in 

 the ftone, to correfpond to the adion or 

 impulfe of the hand. There is nothing 

 but reliftance, which is indeed an adlion, 

 but an adion which is not exerted upon 

 th'e hand : The adion is exerted within 



the 



