The metalogical hexagon of opposition

Authors

  • Jean-Yves Beziau

Keywords:

Hexagon of opposition. Triangle of contrarities. Logical truth. Wittgenstein. Philosophy of Logic.

Abstract

The difference between truth and logical truth is a fundamental distinction of modern logic promoted by Wittgenstein. We show here how this distinction leads to a metalogical triangle of contrariety which can be naturally extended into a metalogical hexagon of oppositions, representing in a direct and simple way the articulation of the six positions of a proposition vis-à-vis a theory. A particular case of this hexagon is a metalogical hexagon of propositions which can be interpreted in a modal way. We end by a semiotic hexagon emphasizing the value of true symbols, in particular the logic hexagon itself.

Author Biography

Jean-Yves Beziau

Department of Philosophy – PPGF-UFRJ.

Published

2013-07-01

Issue

Section

Philosophy of Logic and Mathematics