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Single Idea 12152

[filed under theme 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'

Source

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

Book Ref

'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.


The 18 ideas with the same theme [identity can only ever be in respect of some feature]:

As an infant, Socrates was not the same body, but he was the same human being [Hobbes]
Same person, man or substance are different identities, belonging to different ideas [Locke]
Geach denies Frege's view, that 'being the same F' splits into being the same and being F [Perry on Frege]
Things can only be judged the 'same' by citing some respect of sameness [Goodman]
Denial of absolute identity has drastic implications for logic, semantics and set theory [Wasserman on Geach]
Identity is relative. One must not say things are 'the same', but 'the same A as' [Geach]
If diachronic identities need covering concepts, why not synchronic identities too? [Ayers]
An act of ostension doesn't seem to need a 'sort' of thing, even of a very broad kind [Cartwright,R]
Statements of 'relative identity' are really statements of resemblance [Perry]
Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P]
Relativity of Identity makes identity entirely depend on a category [Wiggins]
To identify two items, we must have a common sort for them [Wiggins]
Gallois is committed to identity with respect to times, and denial of simple identity [Gallois, by Sider]
A clear idea of the kind of an object must precede a criterion of identity for it [Lowe]
We sometimes apply identity without having a real criterion [Hale]
We aren't clear about 'same stuff as this', so a principle of individuation is needed to identify it [Sidelle]
If identity is based on 'true of X' instead of 'property of X' we get the Masked Man fallacy ('I know X but not Y') [Baggini /Fosl, by PG]
Relative identity may reject transitivity, but that suggests that it isn't about 'identity' [Wasserman]