350 ANTIENT METAPHYSICS. Book V. 



Caufe for every thing, and that nothing in nature can be produced 



without a Caufe. 



From thefe principles, I argue thus: As all Motion is by fuccef- 

 fion, as well as Time is, every Motion, however fmall, muft confift 

 of fo many Changes of Place, as well as every portion of Time of 

 fo fnany hours, minutes, or fcconds ; and, if we conceive the 

 Motion to be infinite in its duration, there muft be an infinite num- 

 ber of thofe Changes of Place. Now, as Body cannot move itfelf, 

 that is, make itfelf to change its Place, there muft be fome other 

 Caufe, external or internal, for thofe feveral Changes. The origi- 

 nal impulfe may account for the change from the place A, where 

 the Body is in the beginning of the Motion, to the place B. But 

 there muft likewife be a Caufe for the Motion from B to C. Now, 

 this caufe cannot be the original impulfe, which no longer exifts ; 

 for nothing can be a caufe efficient, actually operating after it has 

 ceafed to exift. There muft therefore be fome other caufe ; and 

 this, as it is not the Body itfelf, muft be either fomething external 

 to it, fuch as an Ether or a Fluid, which I believe is an hypothefis 

 now univerfally rejedted, or it muft be an internal principle, which 

 I call Mind. 



This appearstG me to be ftridly a demonftration a priori^ and fhould, 

 I think, convince every Newtonian, if they would confider only two 

 things. The firft is, That every Motion is truly not one Motion, 

 though it be faid to be one^ but many Motions ; for it is not only 

 divifible into parts, but it is atlually divided into parts not co-ex- 

 iftent but fucceffive ; in which refpedt it differs eftentially from Body, 

 which is not adually divided, but is only divifible, and into parts 

 not fucceffive but co-exiftent. It is, however, faid to be one, as 

 well as Body, not from the co-exiftence of its parts, but from 

 their continued fucceffion, without ftop or interval ; in the fame 

 manner as wc fay Time is one^ fuch as a day or an hour, though it 



certainly 



