412 ANTIENT METAPHYSICS. Book V. 



is concerning the nature and conftitution of the external objedl, the 

 organs of our fenfes, and the medium through which the obje(!^ o- 

 perates upon the organ. But, as all thefe are body, and as we 

 know nothing of the nature or eflence of body, it is impoflible we 

 can demonftrate any thing concerning them, though we are aflured 

 that every thing concerning them is governed by fixed and invariable 

 laws *. 



From the reafon here given, why nothing material can be the fub- 

 je(5t of demonftration, it is evident, on the other hand, why ideas are 

 the proper fubjedt of fcience ; for, as ideas arc the creatures of the 

 mind, we know perfedly their nature and eflence, and therefore can 

 compare them fo, as to perceive their connedion, either intuitively, or 

 by the intervention of other ideas ; Whereas, body, being the work- 

 manlhip of God, we cannot penetrate into its eflence. 



But, do our fenfes give us no information ? and, do we know no- 

 thing at all of fenfible objeds ? My anfwer is, that our fenfes give us fo 

 much information, and fo valuable, that, without fuch information, we 

 could not exift in this world. And,berides, they furnifli to us the ma- 

 terials, out of which intelled forms its objeds : And it is by means 

 of the fenfes that we difcover the /pedes which informs all material 

 things, which alone is fixed and permanent, and which, therefore, is 

 the only objed of fcience. 



But ftill it will be afked, Do we know nothing at all of the matter 

 itfelf ? Can we apprehend nothing of the river as it pafles, to ufe 



the 



* This is the reafon (fays Philoponus, in his commentary upon the fir ft book of 



^^riftotle's firfl Analytics, page 18.) why Ariftotle, in enumerating the feveral fpeci* 



cfes of propofitions, of which the fyllogifm is compofed, has omitted to mention pro- 



. pofiticns concerning individuals, or of which individuals are the fubjcft ; for, fays 



rhiloponus, luch propofitions are entirely ufelefs in matters of fcience. 



