Single Idea 9403

[catalogued under 4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic]

Full Idea

Since to belong, to belong of necessity, and to be possible to belong are different, ..there will be different deductions for each; one deduction will be from necessary terms, one from terms which belong, and one from possible terms.

Gist of Idea

There are three different deductions for actual terms, necessary terms and possible terms

Source

Aristotle (Prior Analytics [c.328 BCE], 29b29-35)

Book Reference

Aristotle: 'Prior Analytics', ed/tr. Smith,Robin [Hackett 1989], p.13


A Reaction

Fitting and Mendelsohn cite this as the earliest thoughts on modal logic. but Kneale and Kneale say that Aristotle got into a muddle, and so was unable to create a workable system.