8 ESSAYS AND OBSERVATIONS 



is an ejBfedl which every one, who has not 

 Itudied philofophy,win attribute to a/JO-u;- 

 tr in the ftone itfelf One would not hefi- 

 tate to draw this conclufion, fhould the 

 llone move upwards j and yet, fetting a- 

 fide habit and cuftom, it muft be evident^ 

 that a ftone can as little move downwards 

 as upwards without a vis matrix. And 

 that this is a juft, as well as natural way 

 of thinking, will appear by analogy. When 

 a man is in motion, we readily afcribe the 

 efFe(5l produced to a power which he pof- 

 fefles to move his limbs. Why then do 

 philofophers deny to the ftone, in the adl 

 of falling, the power of beginning motion, 

 a power which they fo readily alcribe ta 

 the roan ? If ic be objedled, that man is a 

 being endued with a power of moving 

 himfelf and of moving other things, the 

 plain anfwer is, that we are indebted for 

 the knowledge of thefe fac^s to experience; 

 and we have the fame experience for a 

 voucher, that a ftone fet free in the air will 

 move itfelf. And if it be farther urged, 

 that man is a thinking being, the anfwer 

 will readily occur, that a power of be- 

 ginning 



