A new logic / by Charles Mercier.

  • Mercier, Charles Arthur, 1852-1919.
Date:
1912
Catalogue details

Licence: In copyright

Credit: A new logic / by Charles Mercier. Source: Wellcome Collection.

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    two processes—Deduction and Induction—that they do admit, are not clearly or completely distinguished by any logician, nor has the proper distinction between them ever been identified. No logician but Hamilton, and he only dubiously and incompletely, has recognised that Deduction has no function except to explicate the implications of propositions. Every logician regards the syollogism as a means of proceeding from the known to the unknown—a means of discovering fact; every logician takes for granted that Induction, or part of Induction, is an application of the syllogism, speaks of the Inductive syllogism, or considers that Induction is reached by syllogistic reasoning. It has never hitherto been made clear that Deduction is nothing more than inference from postulates, whose truth or falsity is immaterial to the argument; and though it has been recognised by some logicians, in some connections, that Induction is based on propositions that are materially true, the Universal of Induction, as a relation found in experience to be constant, has never been clearly or consistently distinguished from the Universal of Deduction, which is a general rule postulated for the purpose of the argument. The whole of the secular Scholastic discussion of Universals proceeded upon the assumption that the Universal of Deductive reasoning must be true, or ought to be true, in fact. The assumption of Modern Logic, that every proposition refers to reality, or Reality, is a crude attempt to settle the question by dogmatic assertion. As far as it is possible to understand the mysterious and involved phraseology of Modern Logic, new Identity is old Universal writ differently. In short, in Traditional Logic, in Inductive Logic, and in Modern Logic, Deduction, Induction and Analogy are all muddled up together, and endless confusion results. A conspicuous example of this confusion is the riddle of the petitio principii in the syllogism, which Aristotle and all his successors have tried to solve; which every one of them has failed to solve; and which must remain insoluble until the argument from postulates is clearly distinguished from the argu- ment from fact. As Logic makes no clear distinction between Deductive reasoning and Inductive reasoning—between the argwncntum ex postulate), and the argumentum in materiel,—it is not to be expected that it will distinguish between the two “imports,” or modes or degrees of reference to externality, of propositions, on which the