more from Peter Geach

### Single Idea 16075

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

Full Idea

Geach's denial of absolute identity has drastic implications for logic, semantics and set theory. He must deny the axiom of extensionality in set theory, for example.

Gist of Idea

Denial of absolute identity has drastic implications for logic, semantics and set theory

Source

comment on Peter Geach (Reference and Generality (3rd ed) [1980]) by Ryan Wasserman - Material Constitution 6

Book Reference

'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.17

A Reaction

I'm beginning to think we have two entirely different concepts here - the logicians' and mathematicians' notion of when two things are identical, and the ordinary language concept of two things being 'the same'. 'We like the same music'.