110 NAMES AND PROPOSITIONS. 



condition or proviso, it is not a proposition at all, 

 but a plurality of propositions ; since what it expresses 

 is not a single assertion, but several assertions, which, 

 if true when joined, are true also when separated. 

 But there is a kind of proposition which, although it 

 contains a plurality of subjects and of predicates, and 

 may be said in one sense of the word to consist of 

 several propositions, contains but one assertion ; and 

 its truth does not at all imply that of the simple pro- 

 positions which compose it. An example of this is, 

 when the simple propositions are connected by the 

 particle or; as, either A is B or C is D ; or by the 

 particle if; as A is B if C is D. In the former case, 

 the proposition is called disjunctive, in the latter 

 conditional: the name hypothetical was originally 

 common to both. As has been well remarked by 

 Archbishop Whately and others, the disjunctive form 

 is resolvable into the conditional ; every disjunctive 

 proposition being equivalent to two or more condi- 

 tional ones. " Either A is B or C is D," means, 

 " if A is not B, C is D; and if C is not D, A is B." 

 All hypothetical propositions, therefore, though dis- 

 junctive in form, are conditional in meaning; and the 

 words hypothetical and conditional may be, as indeed 

 they generally are, used synonymously. Propositions 

 in which the assertion is not dependent upon a condi- 

 tion, are said, in the language of logicians, to be 

 categorical. 



An hypothetical proposition is not, like the pre- 

 tended complex propositions which we previously 

 considered, a mere aggregation of simple propositions. 

 The simple propositions which form part of the words 

 in which it is couched, form no part of the assertion 

 which it conveys. When we say, If the Koran comes 

 from God, Mahomet is the prophet of God, we do not 



