Single Idea 9615

[catalogued under 4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets]

Full Idea

In current set theory Russell's Paradox is avoided by saying that a condition can only be defined on already existing sets.

Clarification

See Idea 6407 for Russell's Paradox

Gist of Idea

Nowadays conditions are only defined on existing sets

Source

James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)

Book Reference

Brown,James Robert: 'Philosophy of Mathematics' [Routledge 2002], p.19


A Reaction

A response to Idea 9613. This leaves us with no account of how sets are created, so we have the modern notion that absolutely any grouping of daft things is a perfectly good set. The logicians seem to have hijacked common sense.

Related Idea

Idea 9613 Naïve set theory assumed that there is a set for every condition [Brown,JR]