Chap. IV. ANTIENT METAPHYSICS, 221 



metaphors taken from Body, we frequently fpeak of impreflions up- 

 on Mind ; and even Ariftotle, whofe philofophical language is lefs 

 metaphorical than any I know, often fpeaks in that way. Whatever 

 perceptions, therefore, were once in our Mind, we cannot conceive 

 to be worn out of it, or effaced, as we are fure all impreflions 

 upon Body will he fooner or later : And it is for this reafon that 

 we cannot conceive that any perception of the Mind, whether Idea 

 or Senfation, which was once in it, can ever go out of it, though it 

 may not be actually prefent to it for a reafon that ihall be immedi- 

 ately given. 



On the other hand. Body is, by its nature, fleeting and tranfitory, 

 in fo much that it is not precifely the fame Body for two moments 

 together, but is in a confliant flux and viciflltude of change and 

 fuccefl^ion. 



This being the nature of Mind and Body, the next thing 

 to be confidered is, what the confequence muft be of their being 

 fo clofely joined, as they are, in our wonderful compofition. And, 

 in the jirji place, as the union is fo intimate, it feems- to be ne- 

 cefl*ary that the Mind fhould fo far partake of the nature of its com- 

 panion, as not to have its perceptions fixed and permanent, but 

 tranfitory as the particles are, which compofe the body to which it 

 is joined. And, accordingly, its perceptions of Senfe it has only by 

 fucceflTion, one after another ; nor does any perception of that kind 

 laft longer than the imprefllon, made by the external objed upon the 

 organs of fenfe, continues : And, in like manner, our Ideas, which 

 are excited by thofe perceptions, are fleeting and tranfitory. 



But, if thefe perceptions, thus excited, were to be carried away 

 by the flux of the body, as by a ftream, fo that we could not recall 

 them again and prefent them anew to the Mind, it is evident that 



