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Philosophy Dictionary of ArgumentsHome | |||
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Identity: Two objects are never identical. Identity is a single object, to which may be referred to with two different terms. The fact that two descriptions mean a single object may be discovered only in the course of an investigation._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. | |||
Author | Concept | Summary/Quotes | Sources |
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Peter Geach on Identity - Dictionary of Arguments
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_____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments The note [Concept/Author], [Author1]Vs[Author2] or [Author]Vs[term] resp. "problem:"/"solution:", "old:"/"new:" and "thesis:" is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition. |
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 |