more from Penelope Maddy

### Single Idea 13013

#### [catalogued under 4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I]

Full Idea

Most writers agree that if any sense can be made of the distinction between analytic and synthetic, then the Axiom of Extensionality should be counted as analytic.

Gist of Idea

The Axiom of Extensionality seems to be analytic

Source

Penelope Maddy (Believing the Axioms I [1988], §1.1)

Book Reference

-: 'Journal of Symbolic Logic' [-], p.484

A Reaction

[Boolos is the source of the idea] In other words Extensionality is not worth discussing, because it simply tells you what the world 'set' means, and there is no room for discussion about that. The set/class called 'humans' varies in size.