more from Peter Geach

Single Idea 12152

[catalogued under 9. Objects / F. Identity among Objects / 3. Relative Identity]

Full Idea

Identity is relative. When one says 'x is identical with y' this is an incomplete expression. It is short for 'x is the same A as y', where 'A' represents some count noun understood from the context of utterance.

Gist of Idea

Identity is relative. One must not say things are 'the same', but 'the same A as'


Peter Geach (Reference and Generality (3rd ed) [1980], p.39), quoted by John Perry - The Same F I

Book Reference

'Metaphysics - An Anthology', ed/tr. Sosa,E. /Kim,J. [Blackwell 1999], p.90

A Reaction

Perry notes that Geach's view is in conscious opposition to Frege, who had a pure notion of identity. We say 'they are the same insofar as they are animals', but not 'they are the same animal'. Perfect identity involves all possible A's.