14 ANTIENT METAPHYSICS. Book I. 



which is not extended, nor has any quality of any kind, but is fuf- 

 eeptible of all qualities. And, indeed, the antients thought this di- 

 ftindion was fo real, that they made it the foundation of their natu- 

 val philofophy ; for they faid all Bodies, and the whole material 

 world, wctc compofed oi inatter and/orm. This diftindlion is fo im- 

 portant, that it appears to me to be the foundation of the whole phi- 

 lofophy of Mind, and all the dodrlne of ideas ; for an idea is nothing 

 clfe but the form of the thing feparated from the matter*. — That part 

 of Space, which Body occupies, is called its p/ace^ 



Anotherconfequence ofBodyheingmoved^ormoveahk^ is,that,when 

 it is moved, it muft neceflarily impel any other Body that maybe in its 

 way, and which, therefore, obftrudls it in that change of place which 

 is eflential to Motion. And, accordingly, it is a matter of daily ob- 

 fervation, that Bodies in motion either difplace other Bodies, or their 

 motion is flopped by them. From thence refults another neceffary 

 property of Body, viz, refijiance ; for it is impoflible that Body can 

 either impel, or be impelled, without Refiflance. 



With refiftance is neceflarily joined what is called impenetrahd'ity y 

 by which it is impolFible that one Body can occupy the fame portion 

 of fpace with another. Without this quality there could be no re- 

 fiftence in body, nothing ai/riTUTo?, to ufe the expreffion of Greek 

 philofophy, but every Body would pafs through another, as it does 

 through empty fpace. 



Solidity is commonly enumerated among the qualities of Body, as 

 diftindt from Refiftance: I hold it, however, to be the fame in philofo- 

 phical language; but, in common language, a Body is faid to be folid, 

 which refifts more than fome other Bodies do, and has a ftronger and 



firmer 



♦ See what I have further faid upon the fubjeft of Matter, Vol. I. p. 47. 



