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Single Idea 9853

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

Full Idea

Part of Frege's profound new idea of identity is that the criteria for identity of objects of a given kind is not a consequence of the way that kind of object is characterised, but has to be expressly stipulated as part of that characterisation.

Gist of Idea

Identity between objects is not a consequence of identity, but part of what 'identity' means

Source

report of Gottlob Frege (Grundlagen der Arithmetik (Foundations) [1884]) by Michael Dummett - Frege philosophy of mathematics Ch.13

Book Ref

Dummett,Michael: 'Frege: philosophy of mathematics' [Duckworth 1991], p.162

A Reaction

This makes identity a relative concept, rather than an instrinsic concept. Does a unique object have an identity? Do properties have intrinsic identity conditions, making them usable to identify two objects. Deep waters. Has Frege muddied them?

The 20 ideas with the same theme [two objects turning out to be one object]:

15847 Two things relate either as same or different, or part of a whole, or the whole of the part [Plato]
15825 Carneades denied the transitivity of identity [Carneades, by Chisholm]
9853 Identity between objects is not a consequence of identity, but part of what 'identity' means [Frege, by Dummett]
18440 Identity of physical objects is just being coextensive [Quine]
17038 If Hesperus and Phosophorus are the same, they can't possibly be different [Kripke]
17036 Identity statements can be contingent if they rely on descriptions [Kripke]
9905 Identity statements make sense only if there are possible individuating conditions [Benacerraf]
16224 There can't be vague identity; a and b must differ, since a, unlike b, is only vaguely the same as b [Evans, by PG]
16521 A is necessarily A, so if B is A, then B is also necessarily A [Wiggins]
14073 Claims on contingent identity seem to violate Leibniz's Law [Gibbard]
15969 Two things can never be identical, so there is no problem [Lewis]
6047 All identity is necessary, though identity statements can be contingently true [McGinn]
5494 'Lightning is electric discharge' and 'Phosphorus is Venus' are synthetic a posteriori identities [Lycan]
15074 We would understand identity between objects, even if their existence was impossible [Fine,K]
16027 If two things are equal, each side involves a necessity, so the equality is necessary [Gallois]
16231 Occasional Identity: two objects can be identical at one time, and different at others [Gallois, by Hawley]
14081 Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J]
16360 Identity statements are informative if they link separate mental files [Recanati]
14477 Identical entities must be of the same category, and meet the criteria for the category [Thomasson]
14476 Identity claims between objects are only well-formed if the categories are specified [Thomasson]