Single Idea 7690

[catalogued under 10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions]

Full Idea

If sets exist, then the conventional concept of a logically possible world as a proposition set requires a counterintuitive distinction between existence and actuality, between what exists and what is actual.

Gist of Idea

If sets exist, then defining worlds as proposition sets implies an odd distinction between existing and actual


comment on David Lewis (On the Plurality of Worlds [1986]) by Dale Jacquette - Ontology Ch.2

Book Reference

Jacquette,Dale: 'Ontology' [Acumen 2002], p.79

A Reaction

This pinpoints the obvious difficulty that most people have with Lewis's claim that possible worlds exist. Russell's claim that universals 'subsist' (Idea 5409) is a similar attempt to have two different sorts of existence in your ontology.

Related Idea

Idea 5409 Normal existence is in time, so we must say that universals 'subsist' [Russell]