CATEGORICAL JUDGMENTS AND PROPOSITIONS 247 



Sometimes the subject and predicate of one proposition serve as equi 

 valent determinants of the subject and predicate of another proposition. 

 When this is the case a third proposition may be inferred from the combina 

 tion of the two former. Thus, from &quot; Theft is deserving of punishment &quot; and 

 &quot; Unemployed workmen are poor,&quot; we may infer that &quot; Unemployed work 

 men who steal are poor men who deserve punishment &quot;.* 



(6) INFERENCE BY COMPLEX CONCEPTION is the process by 

 which we combine the subject and predicate of a given judgment 

 with some third concept in order to form a new judgment with the 

 complex concepts thus obtained. In the previous kind of inference 

 the subject and predicate of the original proposition were deter 

 mined by the third term ; here they rather determine the third 

 term. 



For example, from &quot; Arsenic is poison &quot; we infer that &quot; A 

 dose of arsenic is a dose of poison &quot; ; from &quot; A dog is a quadru 

 ped &quot; that &quot;The head of a dog is the head of a quadruped&quot; ; 

 from &quot; Poverty is a temptation to crime&quot; that &quot;The removal of 

 poverty is the removal of a temptation to crime&quot;. But here, 

 again, we cannot infer from &quot; Judges are lawyers &quot; that &quot; A 

 majority of judges are a majority of lawyers &quot; ; nor from &quot; A sheep 

 is not a dog &quot; to &quot; The owner of a sheep is not the owner of a 

 dog&quot;. 



(c] IMMEDIATE INFERENCE BY CONVERSE RELATION 2 is the 

 process by which we infer from any relation between one object and 

 another the corresponding relation between the latter and the 

 former. For example, &quot; A is greater than B, therefore B is less 

 than A &quot; ; &quot; Alexander is the son of Philip, therefore Philip is 

 the father of Alexander&quot; ; &quot;Belfast is north of Dublin, therefore 

 Dublin is south of Belfast &quot; ; &quot; John arrived before James, there 

 fore James arrived after John &quot;. 



These relations belong to the &quot;Logic of Relatives,&quot; and are 

 not analysed in ordinary logic, which is supposed to confine itself 

 to such relations, between objects of thought, as can be expressed 

 by the logical copula is (not), are (not). 



WELTON, Logic, i., pp. 248 sqq. KEYNES, Formal Logic , pp. 126 sqq. 

 pp. 420-423. JOSEPH, Logic, pp. 209 sqq. JOYCE, Logic, pp. 92 sqq. 



1 WELTON, op. cit., p. 269. 2 KEYNES, op. cit., pp. 149-51. 



