Chap. II. AN TIEN T METAPHYSICS. 63 



that is, joining to one another, and having one common boundary. 

 Extenfion, as I have faid, is threefold, lengthy breadth, and depths 

 which are called the three dimenfions of body^ and which I have already 

 explained. 



This is the Srft ftep of nature's progrefs in the formation of things; 

 for matter, extended into thefe three dimenfions, becomes what we 

 call body. 



Again, if body were infinite, there would be no fgure ; for fj^ure 

 is body bounded and limited : Figure, therefore, is the fecond Hep of 

 this progrefs of nature *. , ~ 



But matter, thus extended and bounded, though it be body, is not 

 phyftcal body ; in order to make it that, the addition of certain quali- 

 ties is neceffary, and then it becomes one or other of the four elements, 

 commonly fo called, earth, air, fire, ivater ; which are fo called, be- 

 caufe they are the only elements that, as far as we know, have any 

 exiftence by themfelves : For we have hitherto difcovered nothing that 

 is not either earth, air, fire, or ivater^ or refolveable into thefe. 



It is, as we have fai.d, by the addition of certain qualities, that mat- 

 ter extended and figured becomes the four elements. But, what are 

 thefe qualities ? They are, according to the dodrineof antient philofo- 

 phy, oppofttes, fuch as heat and cold, moifi and dry, denfc and rare, 

 heavy and light. Thefe, in that fragment of antient Pythagorean 

 philofophy which I have fo often mentioned, viz. Ocellus Lucanus, 

 arc reckoned among the principles of nature ; the four firft of which, 

 according to Ocellus, conftitute the firjl phyfical bodies, and the four 

 laft, fecondary phyfical bodies; which, according to him, are rough or 



fimooth^ 



* See what Mr Harris fays further upon thefe different forms which matter aflumes; 

 <:ap. 5. PhilofophiCiil Arrangements. 



