more from Engelbretsen,G/Sayward,C

Single Idea 13914

[catalogued under 4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic]

Full Idea

It has often been claimed (e.g. by Leibniz) that a single rule governs all syllogistic validity, called 'dictum de omni et null', which says that what is affirmed or denied of any whole is affirmed or denied of any part of that whole.

Gist of Idea

Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts


Engelbretsen,G/Sayward,C (Philosophical Logic: Intro to Advanced Topics [2011], 8)

Book Reference

Engelbretsen,G/Sayward,C: 'Philosophical Logic: Intro to Advanced Topics' [Continuum 2011], p.143

A Reaction

This seems to be the rule which is captured by Venn Diagrams.