Chap. III. ANTIENT METAPHYSICS. 69 



To illuftrate this by fome examples : — In the relation of dotibk and 

 h'ilf, it is evident, that there muft be two diftind things ; for the lame 

 thing eannot be the do7if?/e of itfelf and the half of itfelt : And, fur- 

 ther, it is evident, that they muH. exift together, or not at all ; for, if 

 there be a double^ there muli be a half ; and, if there be a half^ there 

 muft be a double. Again, in the relation of father and Jon^ ewety 

 one muft conceive the perfons to be diftindt, and to exift together ; 

 for, if there be not a father^ there cannot be ixjon ; and, it there be 

 not ayo72, there cannot be ajather. In like manner, in the relation of 

 underjlanding, and the being underjiood ; v^hat underftands muit necef- 

 farily be diltind from what is underftood; and the one cannot be con- 

 ceived to exift without the other. Alfo, if there be that which de- 

 7/r^j, there muft be a different thing which is defired\ and the two 

 muft neceffarily exift together. Likewife, if there be an agents that 

 is, a thing that a6ls^ there muft neceflarily be a different thing, that 

 is 'patient^ or a5ied upon ; nor can we conceive the one to exift with- 

 out the other : And, for the fatne reafon, if there be that which monjes 

 there muft be a different thing that is moved ; and, wherever the one 

 is, the other muft neceffarily be. 



And 



fenfes^ox that v:hich perceives. All which, he fays, may exifl: feparately and inde. 

 peiuienily one of another. But Ammonius, his commentator, has .inlwercd this ob- 

 jc<5lion moft fatisf.actorily, page iro. by making the obvious diftindion betwixt the 

 things related, and the relation betwixt them; for the things related may fubfill fepa- 

 rately, and altogether independent of one another; but the relation betwixt them 

 cannot cxifl, unlefs the things related exift both at the fame time. Thus, for example, 

 the mind or the underftanding has undoubtedly a feparate cxiftence from the objedt of 

 the undorltanding, or the thing underftood. But the relation betwixt them cannot exift, 

 unlefs they both exift; at the fame time. The fame is true cf what is perceived by 

 fenfe, and the fenfe itfelf. And, in like manner, what moves, confidered by itfelf, 

 has a feparare cxiftence, diftintl: from what is moved. J he human mind, for ex.>m- 

 ple, is, ly its nature, and confidered in itfelf, diftind from the body which it mows ; 

 but the relation betwixt the two, by which the one movesy and the other is viovej, 

 cannot exift but in conjunction with them both. 



