Page:The art of controversy and other posthumous papers (IA artofcontroversy00schouoft).pdf/26

 position as true, and then show what follows from it when we bring it into connection with some other proposition acknowledged to be true. We use the two propositions as the premisses of a syllogism giving a conclusion which is manifestly false, as contradicting either the nature of things, or other statements of our opponent himself; that is to say, the conclusion is false either ad rem or ad hominem. Consequently, our opponent's proposition must have been false; for, while true premisses can give only a true conclusion, false premisses need not always give a false one.

(b) The instance, or the example to the contrary.—This consists in refuting the general proposition by direct reference to particular cases which are included in it in the way in which it is stated, but to which it does not apply, and by which it is therefore shown to be necessarily false.

Such is the framework or skeleton of all forms of disputation; for to this every kind of controversy may be ultimately reduced. The whole of a controversy may, however, actually proceed in the manner described, or only appear to do so; and it may be supported by genuine or spurious arguments. It is just because it is not easy to make out the truth in regard to this matter, that debates are so long and so obstinate.

Nor can we, in ordering the argument, separate actual from apparent truth, since even the disputants are not certain about it beforehand. Therefore I