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Disquotational Principle
The disquotational principle is a philosophical principle which holds that a rational speaker will accept "''p''" if and only if he or she believes ''p''. The quotes indicate that the statement ''p'' is being treated as a sentence, and not as a proposition. This principle is presupposed by claims that hold that substitution fails in certain intensional contexts. Overview Consider the following argument: :(1) Sally accepts the assertion that "Cicero was a famous orator" while dissenting from the assertion that "Tully was a famous orator". :(2) Cicero is Tully :Therefore, (3) Sally believes that Tully was a famous orator. To derive (3), we have to assume that when Sally accepts that "Cicero was a famous orator", she believes that Cicero was a famous orator. Then we can exchange Cicero for Tully, and derive (3). Bertrand Russell thought that this demonstrated the failure of substitutivity of identicals in intensional contexts. In "A Puzzle about Belief,"Kripke, Saul. "A Puzzle ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
If And Only If
In logic and related fields such as mathematics and philosophy, "if and only if" (shortened as "iff") is a biconditional logical connective between statements, where either both statements are true or both are false. The connective is biconditional (a statement of material equivalence), and can be likened to the standard material conditional ("only if", equal to "if ... then") combined with its reverse ("if"); hence the name. The result is that the truth of either one of the connected statements requires the truth of the other (i.e. either both statements are true, or both are false), though it is controversial whether the connective thus defined is properly rendered by the English "if and only if"—with its pre-existing meaning. For example, ''P if and only if Q'' means that ''P'' is true whenever ''Q'' is true, and the only case in which ''P'' is true is if ''Q'' is also true, whereas in the case of ''P if Q'', there could be other scenarios where ''P'' is true and ''Q'' is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disquotational Theory Of Truth
According to the redundancy theory of truth (also known as the disquotational theory of truth), asserting that a statement is true is completely equivalent to asserting the statement itself. For example, asserting the sentence "'Snow is white' is true" is equivalent to asserting the sentence "Snow is white". The philosophical redundancy theory of truth is a deflationary theory of truth. Overview Redundancy theorists infer from this premise that truth is a redundant concept—in other words, that "truth" is merely a word that it is conventional to use in certain contexts but not one that points to anything in reality. The theory is commonly attributed to Frank P. Ramsey, who argued that the use of words like ''fact'' and ''truth'' was nothing but a roundabout way of asserting a proposition, and that treating these words as separate problems in isolation from judgment was merely a "linguistic muddle", though there remains some debate as to the correct interpretation of his position (Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theorems
In mathematics, a theorem is a statement that has been proved, or can be proved. The ''proof'' of a theorem is a logical argument that uses the inference rules of a deductive system to establish that the theorem is a logical consequence of the axioms and previously proved theorems. In the mainstream of mathematics, the axioms and the inference rules are commonly left implicit, and, in this case, they are almost always those of Zermelo–Fraenkel set theory with the axiom of choice, or of a less powerful theory, such as Peano arithmetic. A notable exception is Wiles's proof of Fermat's Last Theorem, which involves the Grothendieck universes whose existence requires the addition of a new axiom to the set theory. Generally, an assertion that is explicitly called a theorem is a proved result that is not an immediate consequence of other known theorems. Moreover, many authors qualify as ''theorems'' only the most important results, and use the terms ''lemma'', ''proposition'' and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belief
A belief is an attitude that something is the case, or that some proposition is true. In epistemology, philosophers use the term "belief" to refer to attitudes about the world which can be either true or false. To believe something is to take it to be true; for instance, to believe that snow is white is comparable to accepting the truth of the proposition "snow is white". However, holding a belief does not require active introspection. For example, few carefully consider whether or not the sun will rise tomorrow, simply assuming that it will. Moreover, beliefs need not be ''occurrent'' (e.g. a person actively thinking "snow is white"), but can instead be ''dispositional'' (e.g. a person who if asked about the color of snow would assert "snow is white"). There are various different ways that contemporary philosophers have tried to describe beliefs, including as representations of ways that the world could be (Jerry Fodor), as dispositions to act as if certain things are true (Rod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principles
A principle is a proposition or value that is a guide for behavior or evaluation. In law, it is a rule that has to be or usually is to be followed. It can be desirably followed, or it can be an inevitable consequence of something, such as the laws observed in nature or the way that a system is constructed. The principles of such a system are understood by its users as the essential characteristics of the system, or reflecting system's designed purpose, and the effective operation or use of which would be impossible if any one of the principles was to be ignored. A system may be explicitly based on and implemented from a document of principles as was done in IBM's 360/370 ''Principles of Operation''. Examples of principles are, entropy in a number of fields, least action in physics, those in descriptive comprehensive and fundamental law: doctrines or assumptions forming normative rules of conduct, separation of church and state in statecraft, the central dogma of molecular biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philosophy Of Language
In analytic philosophy, philosophy of language investigates the nature of language and the relations between language, language users, and the world. Investigations may include inquiry into the nature of meaning, intentionality, reference, the constitution of sentences, concepts, learning, and thought. Gottlob Frege and Bertrand Russell were pivotal figures in analytic philosophy's "linguistic turn". These writers were followed by Ludwig Wittgenstein ('' Tractatus Logico-Philosophicus''), the Vienna Circle, logical positivists, and Willard Van Orman Quine. In continental philosophy, language is not studied as a separate discipline. Rather, it is an inextricable part of many other areas of thought, such as phenomenology, structural semiotics, language of mathematics, hermeneutics, existentialism, deconstruction and critical theory. History Ancient philosophy In the West, inquiry into language stretches back to the 5th century BC with Socrates, Plato, Aristotl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-schema
The T-schema ("truth schema", not to be confused with "Convention T") is used to check if an inductive definition of truth is valid, which lies at the heart of any realisation of Alfred Tarski's semantic theory of truth. Some authors refer to it as the "Equivalence Schema", a synonym introduced by Michael Dummett. The T-schema is often expressed in natural language, but it can be formalized in many-sorted predicate logic or modal logic; such a formalisation is called a "T-theory." T-theories form the basis of much fundamental work in philosophical logic, where they are applied in several important controversies in analytic philosophy. As expressed in semi-natural language (where 'S' is the name of the sentence abbreviated to S): 'S' is true if and only if S. Example: 'snow is white' is true if and only if snow is white. The inductive definition By using the schema one can give an inductive definition for the truth of compound sentences. Atomic sentences are assigned truth v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convention T
A semantic theory of truth is a theory of truth in the philosophy of language which holds that truth is a property of sentences. Origin The semantic conception of truth, which is related in different ways to both the correspondence and deflationary conceptions, is due to work by Polish logician Alfred Tarski. Tarski, in "On the Concept of Truth in Formal Languages" (1935), attempted to formulate a new theory of truth in order to resolve the liar paradox. In the course of this he made several metamathematical discoveries, most notably Tarski's undefinability theorem using the same formal technique Kurt Gödel used in his incompleteness theorems. Roughly, this states that a truth-predicate satisfying Convention T for the sentences of a given language cannot be defined ''within'' that language. Tarski's theory of truth To formulate linguistic theories without semantic paradoxes such as the liar paradox, it is generally necessary to distinguish the language that one is talking ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Use–mention Distinction
The use–mention distinction is a foundational concept of analytic philosophy, according to which it is necessary to make a distinction between a word (or phrase) and it.Devitt and Sterelny (1999) pp. 40–1 W.V. Quine (1940) p. 24 Many philosophical works have been "vitiated by a failure to distinguish use and mention". The distinction can sometimes be pedantic, especially in simple cases where it is obvious. The distinction between use and mention can be illustrated with the word ''cheese'': * ''Use'': Cheese is derived from milk. * ''Mention'': 'Cheese' is derived from (the Anglian variant of) the Old English word ''ċēse'' (). The first sentence is a statement about the substance called "cheese": it ''uses'' the word 'cheese' to refer to that substance. The second is a statement about the word 'cheese' as a signifier: it ''mentions'' the word without ''using'' it to refer to anything other than itself. Note the quotation marks. Grammar In written language, ''menti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignacy Jan Paderewski
Ignacy Jan Paderewski (; – 29 June 1941) was a Polish pianist and composer who became a spokesman for Polish independence. In 1919, he was the new nation's Prime Minister and foreign minister during which he signed the Treaty of Versailles, which ended World War I. A favorite of concert audiences around the world, his musical fame opened access to diplomacy and the media, as possibly did his status as a freemason, and charitable work of his second wife, Helena Paderewska. During World War I, Paderewski advocated an independent Poland, including by touring the United States, where he met with President Woodrow Wilson, who came to support the creation of an independent Poland in his Fourteen Points at the Paris Peace Conference in 1919, which led to the Treaty of Versailles.Hanna Marczewska-Zagdanska, and Janina Dorosz, "Wilson – Paderewski – Masaryk: Their Visions of Independence and Conceptions of how to Organize Europe," ''Acta Poloniae Historica'' (1996), Issue 73, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saul Kripke
Saul Aaron Kripke (; November 13, 1940 – September 15, 2022) was an American philosopher and logician in the analytic tradition. He was a Distinguished Professor of Philosophy at the Graduate Center of the City University of New York and emeritus professor at Princeton University. Since the 1960s, Kripke has been a central figure in a number of fields related to mathematical logic, modal logic, philosophy of language, philosophy of mathematics, metaphysics, epistemology, and recursion theory. Much of his work remains unpublished or exists only as tape recordings and privately circulated manuscripts. Kripke made influential and original contributions to logic, especially modal logic. His principal contribution is a semantics for modal logic involving possible worlds, now called Kripke semantics. He received the 2001 Schock Prize in Logic and Philosophy. Kripke was also partly responsible for the revival of metaphysics after the decline of logical positivism, claiming necessity i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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