Chap. I. A N T I E N T METAPHYSICS. 179 



there are many things that we are fure do certainly exift, and yet 

 wc have no clear conception of the manner of their exiftcncc. This 

 is the cafe with refpedt to the Supreme Mind, and even our own 

 Minds, of the exiftence of which we have much greater certain- 

 ty than of the exiftence of Body. And, as to our knowledge, it 

 would be exceedingly imperfedt without the Idea of Subftance, or 

 rather we fhould have no knowledge at all : For we could not con- 

 ceive Qualities, without, at the fame time, having an Idea of fome 

 Subftance in which they are inherent ; and I hope I have already 

 fhown, and will further fhow, that, by diftinguifhing the feveral 

 fubftances of which we are compofed, there is fomething to be ad- 

 ded to our knowledge. 



There are other two Ideas of the greateft importance to philofo- 

 phy ; but which likewife are neither Senfations nor Reflexions. 

 Thefe are the Ideas of Matter and Form^ of which the whole 

 Material world is compofed : For it is only the compofite of thefe 

 two that is perceived by the Senfes ; but it is Intellect alone that 

 can make the feparation, and conceive each of them by itfelf. Mat- 

 ter, without form of any kind, is not only no Perception of the 

 Brute, but it is an Idea of the Human Mind, fo remote from com- 

 mon fenfe and obfervation, that I doubt very few of our modern 

 philofophers have any fuch Idea : And, as to Form without Mat- 

 ter, 1 do not believe that Mr Locke was learned enough to know, 

 that Ider.s, of which he fpcaks fo much, are nothing elfe but Forms 

 of that kind. And, as to fubftaniial Forms, it is plain from what 

 he fays, that he had not the leaft Idea of them ; for he did not 

 •know enough of the fyftem of Nature, to know, that, in all natu- 

 ral Subftances, there is a certain Form from which all the qualities 

 of the Subftance refult: And this is what is called, in the language of 

 the Peripatetics, the Siihjl ant nil Form of the thing. In every fubjed of 

 Science this Form muft be difcovercd, otherwife there could be no 

 ^Science. Thus, for example, the Geometer muft know the Effence 



Z 2 or 



