CHAPTEK II. 



OF RATIOCINATION, OR SYLLOGISM. 



1. THE analysis of the Syllogism has been so accurately 

 and fully performed in the common manuals of Logic, that in 

 the present work, which is not designed as a manual, it is suf- 

 ficient to recapitulate, memorise causa, the leading results of 

 that analysis, as a foundation for the remarks to be afterwards 

 made on the functions of the syllogism, and the place which it 

 holds in science. 



To a legitimate syllogism it is essential that there should be 

 three, and no more than three, propositions, namely, the con- 

 clusion, or proposition to be proved, and two other propositions 

 which together prove it, and which are called the premises. It 

 is essential that there should be three, and no more than three, 

 terms, namely, the subject and predicate of the conclusion, and 

 another called the middleterin, which must be found in both 

 premises, since it is by means of it that the other two terms are 

 to be connected together. The predicate of the conclusion is 

 called the major term of the syllogism ; the subject of the con- 

 clusion is called the minor term. As there can be but three 

 terms, the major and minor terms must each be found in one, 

 and only one, of the premises, together with the middleterm 

 which is in them both. The premise which contains the mid- 

 dleterm and the major term is called the major premise ; that 

 which contains the middleterm and the minor term is called 

 the minor premise. 



Syllogisms are divided by some logicians into three figures, 

 by others into four, according to the position of the middle- 

 term, which may either be the subject in both premises, the 

 predicate in both, or the subject in one and the predicate in 

 the other. The most common case is that in which the middle- 

 term is the subject of the major premise and the predicate of 



