CHAPTER Ht. 501 5EcT. IL Two general Tests of true Syllogisms, and Methods of solving all Sophisms. BESIDES 'the special description of true syllogisms and sophisms already given, and the rules by which the one are framed, and, the other refuted, there are these two general me- thods of reducing all syllogisms whatsoever to a test of their truth or falsehood. I. The first is, that the " premises must, at least implicitly, ebntain the conclusion ; or thus, one of the premises must con- tain the conclusion, and the other must skew that the conclusion is contained in it." The reason of this rule is this ; when any proposition is offered to be proved, it is necessary to find another proposition which confirms it, which may be called the containing proposition ; but because the second must not contain the first in an express manner, and in the same words '5, therefore it is ne- cessary that a third or ostensive proposition be found out, to shew that the second proposition contains the first, which was to be proved. Let us make an experiment of this syllogism " Who- soever is a slave to his natural inclinations is miserable ; the wicked man is a slave to his natural inclinations : therefore the Wicked man is miserable." Here it is evident that the major proposition contains the conclusion ; for under the general cha- racter of a slave to natural inclinations, a wicked man is con- tained or included ; and the minor proposition declares it ; whence the conclusion is evidently deduced, that the wicked man is miserable. In many affirmative syllogisms we may suppose either the major or the minor to contain the conclusion, and the other to spew it ; for there is no great difference. But in negative syllo- gisms it is the negative proposition that contains the conclusion, and the affirmative proposition shows it ; as " every wise, man masters his passions ; no angry man masters his passions ; there- fore no angry man is wise." Here it is more natural to suppose the minor to be the containing proposition ; it is the minor im- plicitly denies wisdom concerning an angry min, because mas- tering the passions is included in wisdom, and the major shews it. Note, This rule may be applied to complex and conjunc- tive, as well as simple- syllogisms, and is adapted to shew the truth or falsehood of any ofthem. II. The second is this ; " As the terms in every syllogism are usually repeated twice, so they must be taken precisely in the same sense in both places :" for the greatest part of mistakes that arise in forming syllogisms, is derived from some * It is confessed that conditional and diajanctive major propositions do ex- pressly contain all that is in the conclusion; but then it is not in a certain and conclusive manner, but only in a dubious form of speech, and mingled sub ether terms ; and therefore it is not the came express proposition. ti3
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