## Philosophy Dictionary of ArgumentsHome | |||

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Truth value: The truth value is that what is attributed to a statement or an interpreted logical formula with regard to whether it is true or false. In classical logic, there are two truth values, true and false. In multi-valued logics there can be three to infinitely many truth values. In the latter case, these are often regarded as probabilities. For trivalent logics, the third value is often "indeterminate", "neither true nor false" or "neither proved nor disproved". See also negation, strong negation, weak negation, intuitionism, probability, fuzzy logic, extensionality._____________ 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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W.V.O. Quine on Truth Values - Dictionary of Arguments VII (d) 71 Propositional Calculus/indistinguishability/theoretical terms/Quine: "p", "q" etc. refer to propositional concepts, whatever they may be. But we know that propositional concepts like truth values are not distinguishable in terms of the calculus, the expressiveness of the calculus is limited. - - - VII (f) 112 Truth Values/Quine: can be allowed as abstract entities. VII 115 Truth Value/Quine: is not an abstract entity to which we appeal with assertions. VII (h) 154 Range/Russell: a change in the range of a description is neutral to the truth value of any sentence. Quine: but only if the description designates something. - - - Lauener XI 38 Quantification/Lauener/(s): truth values can only be attributed to quantified sentences. - - - Quine I 226 Vagueness/Quine: leaves the truth values untouched. Therefore it can be useful. >Vagueness. I 263ff Truth Value/intension/extension/Quine: in extensional contexts a singular term may be replaced by a singular term with the same name without changing the truth value of the sentence. This is not possible in opaque (intensional) contexts. >Intensions, >Extensions, >Opacity. I 266 Opaque Contexts/Truth Value/Frege: in a construction with a propositional attitude, a sentence or term may not denote truth values, a class or an individual, but functions as the "name of a thought" or the name of a property or an "individual concept". ((s) In non-intensional contexts, a sentence in Frege's work designates a truth value, "The True," or "The False". > "Great Fact", >"Slingshot Argument"). - - - II 192 From today's point of view, quantifier logic is nothing more than a further development of the logic of truth functions. The truth value of a truth function can be calculated on the basis of the truth values of the arguments. Why then does quantifier logic not become decidable by truth tables? This validity criterion would be too strict because the quantified sub-expressions are not always independent of each other. Some sub-expressions may turn out to be untrue, but are unworthy of a closer look at an assignment to truth values. See also >Truth tables. - - - III 281 Truth value/Existence/Nonexistence/Ontology/Logic/Quine: which truth values have sentences like "Zerberus barking"? (See also >Unicorn example). The answer "wrong" would be premature. III 282 Problem: for all sentences that would be wrong, there would be a negation that would be true! Our derivation methods do not prove anything in case the object does not exist. What would have to be proved is based on an unfulfilled condition. Truth value gap/Quine: comes from everyday language, in logic we have to fill it. And be it arbitrary. Every sentence should have a truth value (true or false). >Everyday language. That was the reason for the convenient extension of the term conditional in § 3,m which generally allowed a truth value for the whole conditional. We now need a similar extension for singular terms, which do not describe anything. But this cannot be achieved by an all-encompassing decision. But this can be done for simple sentences, from which we derive rules for compound sentences. Def simple predicate: is a predicate if it does not explicitly have the form of a quantification, negation, conjunction, alternation etc. of shorter components. If a simple predicate is applied to a singular term that does not denote anything, the sentence in question is to be considered false. Then e.g. "Zerberus barks" is wrong, because it represents an application of the predicate "[1] barks" to "Zerberus". V 112 Truth values/Language learning/Quine: truth values correspond to a more advanced level of learning. Using different theories for different subject areas V 113 we finally learn (if at all) which judgement to make in the indeterminate cases of conjunction or alternation in the middle of the table. Logic/Learn languages/Quine: bivalent logic is a theoretical product which, like all theory, is only learned indirectly. How, we can only speculate about that. - - - VI 128 Singular terms/truth value/sense/divalued logic/unicorn/Quine: in the case of unrelated singular terms or failed descriptions, we may not know the truth value. It is not profitable to describe such sentences as meaningless, since the existence of the object could turn out (e.g. Pluto). It is alright to leave the truth value open, but not the meaning of a sentence! VI 129 Singular terms/truth value/sense/divalued logic/unicorn/Quine: in the case of unrelated singular terms or failed descriptions, we may not know the truth value. It is not profitable to describe such sentences as meaningless, since the existence of the object could turn out (e.g. Pluto). It is alright to leave the truth value open, but not the meaning of a sentence! VI 131 Antirealism/Sentence of the excluded Middle/Dummett/Quine: Dummett turns against the sentence of the excluded middle with epistemological arguments. (Also Brouwer): No sentence is true or false, as long as no procedure for the determination of the truth value is known. _____________ 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. |
Quine I W.V.O. Quine Word and Object, Cambridge/MA 1960 German Edition: Wort und Gegenstand Stuttgart 1980 Quine II W.V.O. Quine Theories and Things, Cambridge/MA 1986 German Edition: Theorien und Dinge Frankfurt 1985 Quine III W.V.O. Quine Methods of Logic, 4th edition Cambridge/MA 1982 German Edition: Grundzüge der Logik Frankfurt 1978 Quine V W.V.O. Quine The Roots of Reference, La Salle/Illinois 1974 German Edition: Die Wurzeln der Referenz Frankfurt 1989 Quine VI W.V.O. Quine Pursuit of Truth, Cambridge/MA 1992 German Edition: Unterwegs zur Wahrheit Paderborn 1995 Quine VII W.V.O. Quine From a logical point of view Cambridge, Mass. 1953 Quine VII (a) W. V. A. Quine On what there is InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (b) W. V. A. Quine Two dogmas of empiricism InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (c) W. V. A. Quine The problem of meaning in linguistics InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (d) W. V. A. Quine Identity, ostension and hypostasis InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (e) W. V. A. Quine New foundations for mathematical logic InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (f) W. V. A. Quine Logic and the reification of universals InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (g) W. V. A. Quine Notes on the theory of reference InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (h) W. V. A. Quine Reference and modality InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VII (i) W. V. A. Quine Meaning and existential inference InFrom a Logical Point of View, , Cambridge, MA 1953 Quine VIII W.V.O. Quine Designation and Existence, in: The Journal of Philosophy 36 (1939) German Edition: Bezeichnung und Referenz InZur Philosophie der idealen Sprache, J. Sinnreich (Hg), München 1982 Quine IX W.V.O. Quine Set Theory and its Logic, Cambridge/MA 1963 German Edition: Mengenlehre und ihre Logik Wiesbaden 1967 Quine X W.V.O. Quine The Philosophy of Logic, Cambridge/MA 1970, 1986 German Edition: Philosophie der Logik Bamberg 2005 Quine XII W.V.O. Quine Ontological Relativity and Other Essays, New York 1969 German Edition: Ontologische Relativität Frankfurt 2003 Quine XIII Willard Van Orman Quine Quiddities Cambridge/London 1987 Q XI H. Lauener Willard Van Orman Quine München 1982 Quine XIII Willard Van Orman Quine Quiddities Cambridge/London 1987 |

Ed. Martin Schulz, access date 2024-03-05