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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    know the meaning of ‘ quadruped ’ learns something from this proposition. To him it conveys information, and a knowledge of fact. It seems clear that to say that a triangle is a three-angled figure, or that the functions of an archdeacon are archi-diaconal functions, is to use propositions that are ‘ verbal ’ in quite another sense than that in which ‘ A quadruped is a four-footed animal1 is * verbal ’; and in my view, propositions may be classified, with respect to their significance, in the following way. A proposition may express a relation between words alone, without regard to their meaning. Such propositions may be termed Insignificant. Or it may express a relation between the meanings of words as words, without more reference to the things to which the words refer than is inseparable from the use of the words. Such a proposition may be termed Definitive, or Defining. Or it may refer primarily, not to the words, but to the things named by the words; and is then a Substantial proposition. Insignificant Propositions. These are propositions in which a relation is predicated between words alone, without regard to the meanings of the words. Strictly speaking, such propositions are not true propositions, but bastard, pseudo, or quasi-propositions, since the relation such a proposition purporte to express has no answering relation in the mind. Since, however, such propositions are occasionally used either legitimately, with full knowledge of their emptiness ; or illegitimately, without appreciation by the user that they are but empty forms of words, it is necessary to include them in an enumeration of propositions. Insignificant propositions are of three kinds,—the Synonymous proposition, the Unintelligible proposition, and the Contradiction in terms. The Synonymous Proposition. This forms one kind of the propositions that are called verbal by logicians. It is a proposition whose terms are synonymous on the face of them, such as ‘ The functions of an archdeacon are archi- diaconal ’; ‘ Opium causes sleep by means of its soporific virtue ’; ‘ A quadruped is a four-footed animal ’; ‘ A brighter light implies increased luminosity.’ In each of these quasi-propositions, there