THE PREDICABLES. 73 



we may refer to the fourfold classification implied by Aristotle who did not 

 explicitly treat of the predicables. It may be summed up as follows : * 



(1) When P (the predicate) agrees both in denotation and in connota 

 tion with -S&quot; (the subject), thus giving all the attributes which fully explain the 

 nature of the subject, its relation to the latter is called definition (opos), e.g. 

 man is a rational animal. 



(2) When P agrees in denotation with S while differing wholly from it 

 in connotation, thus giving some attribute that necessarily follows from the 

 connotation of S, the relation of P to S is described as property -, proprium 

 (ZSiov) ; e.g. men use tools? 



(3) When P differs in denotation from 5 but partially agrees with it in 

 connotation by giving that portion of the connotation of S which the latter 

 has in common with some other things, then the relation of P to S is called 

 genus (ytvos) , e.g. man is an animal? 



(4) Finally when P differs in denotation from 5, and also in connotation 

 by giving some attribute that may or may not be found in 5, then the relation 

 of P to 6* is called accidens (a-vp-^e^Kos) ; e.g. some men are red-haired. 



The analysis of this four-fold division will be included in our exposition 

 of the traditional scheme of Porphyry^ Five Predicables. It is briefly summed 

 up thus by Mr. Joseph : 4 &quot; where the predicate of a judgment is commen 

 surate with the subject, there it is either the definition or a property of it : 

 where it is not commensurate, there it is either part of the definition, i.e. genus 

 or differentia, or an accident &quot;. 



44. THE FIVE PREDICABLES: How TO ARRIVE AT THEM. 

 ESSENCE AND CONNOTATION. The following simple considera 

 tion will enable us to see that there are five and only five pos 

 sible relations between the intension of the predicate and the 

 intension of the subject of a logical proposition. The predicate 

 of any affirmative proposition is an attribute (or group of attri 

 butes) which (a} either belongs to the nature or essence of the 

 subject as connoted by the class name of the latter, or (&) does 

 not belong to it. In the former case it will either give us (i) the 

 whole nature or essence of the subject, or (2) the part of that nature 



1 WELTON, Logic, i., p. 78. 



2 If P partly agreed in connotation with S by giving that part of the connotation 

 of S which differentiated S from other things that also agreed partially in connotation 

 with S, the relation of P to S would be called differentia (Suupopd) ; e.g. man is 

 rational. Porphyry s scheme differs from the present one in making distinct and 

 explicit mention of this predicable. 



3 When P gives the portion of the connotation of S which differentiates the 

 latter from other things, e.g. its differentia, this latter will sometimes not have the 

 same denotation as S. For example, angels are rational as well as men. Only 

 when the differentia is such that it can belong to S alone, is it identical in denota 

 tion with the latter ; and it is only in such cases that we have the ideally perfect 

 differentia from the point of view of scientific knowledge. Cf. 47, 58, 62; also 

 JOSEPH, cp. cit., p. 116. 



4 op. cit., p. 59. 



