Single Idea 6020

[catalogued under 5. Theory of Logic / E. Structures of Logic / 1. Logical Form]

Full Idea

Definitions are identical to universal propositions in meaning, and only differ in syntax, for whoever says 'Man is a rational mortal animal' says the same thing in meaning as whoever says 'If something is a man, that thing is a rational mortal animal'.

Gist of Idea

'Man is a rational mortal animal' is equivalent to 'if something is a man, that thing is a rational mortal animal'

Source

Sextus Empiricus (Against the Professors (six books) [c.180], 11.8)

Book Reference

'The Hellenistic Philosophers:Vol.1 translations', ed/tr. Long,A. /Sedley,D. [CUP 1987], p.180


A Reaction

How strikingly like Bertrand Russell's interest and solutions. Sextus shows a straightforward interest in logical form, of a kind we associate with the twentieth century. Did Sextus Empiricus invent quantification?