Single Idea 6047

[catalogued under 9. Objects / F. Identity among Objects / 6. Identity between Objects]

Full Idea

All identity is necessary, although there can be contingently true identity statements - those that contain non-rigid designators.

Clarification

'Rigid designators' baptise things across all possible worlds (e.g. Aristotle, water) [Idea 4949]

Gist of Idea

All identity is necessary, though identity statements can be contingently true

Source

Colin McGinn (Logical Properties [2000], Ch.1 n5)

Book Reference

McGinn,Colin: 'Logical Properties' [OUP 2003], p.3


A Reaction

A nice case of the need to keep epistemology and ontology separate. An example might be 'The Prime Minister wears a wig', where 'Prime Minister' may not be a rigid designator. 'Winston wears a wig' will be necessary, if true (which it wasn't).