@misc{Lexicon of Arguments, title = {Quotation from: Lexicon of Arguments – Concepts - Ed. Martin Schulz, 28 Mar 2024}, author = {Geach,Peter}, subject = {Identity}, note = {I 218 Identity/GeachVsFrege: identity is not a relation - "Is an A" does not mean "has identity with A" - (whereby "A" is a name). VsFrege: (in Frege, basic principles of artihmetics) instead of "There are just as many Fs as Gs": "Either any given object F iff it is a G, or there is a relation that is a one-to-one correspondence between the Fs and Gs". But this must not be an identity. I 226 Identity/Geach: only objects can be strictly identical. - In terms, there is only analogous identity: if they are coextensive. >Coextensive. I 238 Identity/GeachVsQuine: Thesis: Identity is relative. - If someone says "x is identical to y", this is an incomplete expression. - It is an abbreviation for "x is the same as y". - (Weird, that Frege did not represent this). >Identity/Quine. Identity/tradition/Geach: can be expressed by a single schema. (1) l- Fa (x)(Fx u x = a) - everyday-language: whatever is true of something which is identical with an object y is true of a and vice versa. From this we derive the law of self-identity: "l-a = a". Because we take "Fx" for "x unequal a", then schema (1) gives us: (2) l- (a unequal a) Vx(y unequal a u x = a) - this,of course, gives "l-a = a" I 240 Identity/Geach: if we demand strict identity, regardless of the theory in which we move, we get into the semantic paradoxes such as Grelling's or Richard's >Grelling's paradox. Solution: relative identity on theory or language, indissibility/"indiscernibility"/Quine -> Partial identity. 1. Frege, G. (1893). Grundgesetze der Arithmetik. Jena: Hermann Pohle. --- Tugendhat I 37 Identity/Dummett/Geach: "=" can only be used with reference to objects. >Equal sign. - - - Habermas IV 158 Identity/Geach/Habermas: Peter Geach argues that identity predicates can only be used meaningfully in connection with the general characterization of a class of objects.(1) (See also Criteria/Henrich, HenrichVsGeach). E.g. Person/Identification/Habermas: Persons cannot be identified under the same conditions as observable objects. In the case of persons, spatiotemporal identification is not sufficient. Also see >Identity/Henrich. 1.P.Geach, Ontological Relativity and Relative Identity, in: K. Munitz, Logic and Ontology, NY. 1973}, note = { Gea I P.T. Geach Logic Matters Oxford 1972 Tu I E. Tugendhat Vorlesungen zur Einführung in die Sprachanalytische Philosophie Frankfurt 1976 Tu II E. Tugendhat Philosophische Aufsätze Frankfurt 1992 Ha I J. Habermas Der philosophische Diskurs der Moderne Frankfurt 1988 Ha III Jürgen Habermas Theorie des kommunikativen Handelns Bd. I Frankfurt/M. 1981 Ha IV Jürgen Habermas Theorie des kommunikativen Handelns Bd. II Frankfurt/M. 1981 }, file = {http://philosophy-science-humanities-controversies.com/listview-details.php?id=231021} url = {http://philosophy-science-humanities-controversies.com/listview-details.php?id=231021} }