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Susanne Bobzien
Susanne Bobzien (born 1960) is a German-born philosopherWho'sWho in America 2012, 64th Edition whose research interests focus on philosophy of logic and language, determinism and freedom, and ancient philosophy. She currently is senior research fellow at All Souls College, Oxford and professor of philosophy at the University of Oxford. Early life Bobzien was born in Hamburg, Germany, in 1960. She graduated in 1985 with an M.A. at Bonn University, and in 1993 with a doctorate in philosophy (D.Phil.) at Oxford University, where from 1987–1989 she was affiliated with Somerville College. Academic career Bobzien currently holds the position of senior research fellow at All Souls College, Oxford and is professor of philosophy at Oxford University. She was appointed to a senior professorship in philosophy at Yale in 2001 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Susanne Bobzien
Susanne Bobzien (born 1960) is a German-born philosopherWho'sWho in America 2012, 64th Edition whose research interests focus on philosophy of logic and language, determinism and freedom, and ancient philosophy. She currently is senior research fellow at All Souls College, Oxford and professor of philosophy at the University of Oxford. Early life Bobzien was born in Hamburg, Germany, in 1960. She graduated in 1985 with an M.A. at Bonn University, and in 1993 with a doctorate in philosophy (D.Phil.) at Oxford University, where from 1987–1989 she was affiliated with Somerville College. Academic career Bobzien currently holds the position of senior research fellow at All Souls College, Oxford and is professor of philosophy at Oxford University. She was appointed to a senior professorship in philosophy at Yale in 2001 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Problem Of Multiple Generality
The problem of multiple generality names a failure in traditional logic to describe certain intuitively valid inferences. For example, it is intuitively clear that if: :''Some cat is feared by every mouse'' then it follows logically that: :''All mice are afraid of at least one cat''. The syntax of traditional logic (TL) permits exactly four sentence types: "All As are Bs", "No As are Bs", "Some As are Bs" and "Some As are not Bs". Each type is a quantified sentence containing exactly one quantifier. Since the sentences above each contain two quantifiers ('some' and 'every' in the first sentence and 'all' and 'at least one' in the second sentence), they cannot be adequately represented in TL. The best TL can do is to incorporate the second quantifier from each sentence into the second term, thus rendering the artificial-sounding terms 'feared-by-every-mouse' and 'afraid-of-at-least-one-cat'. This in effect "buries" these quantifiers, which are essential to the inference's validity, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modal Companion
In logic, a modal companion of a superintuitionistic (intermediate) logic ''L'' is a normal modal logic that interprets ''L'' by a certain canonical translation, described below. Modal companions share various properties of the original intermediate logic, which enables to study intermediate logics using tools developed for modal logic. Gödel–McKinsey–Tarski translation Let ''A'' be a propositional intuitionistic formula. A modal formula ''T''(''A'') is defined by induction on the complexity of ''A'': :T(p)=\Box p, for any propositional variable p, :T(\bot)=\bot, :T(A\land B)=T(A)\land T(B), :T(A\lor B)=T(A)\lor T(B), :T(A\to B)=\Box(T(A)\to T(B)). As negation is in intuitionistic logic defined by A\to\bot, we also have :T(\neg A)=\Box\neg T(A). ''T'' is called the Gödel translation or Gödel–McKinsey– Tarski translation. The translation is sometimes presented in slightly different ways: for example, one may insert \Box before every subformula. All such variants are prova ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intuitionistic Logic
Intuitionistic logic, sometimes more generally called constructive logic, refers to systems of symbolic logic that differ from the systems used for classical logic by more closely mirroring the notion of constructive proof. In particular, systems of intuitionistic logic do not assume the law of the excluded middle and double negation elimination, which are fundamental inference rules in classical logic. Formalized intuitionistic logic was originally developed by Arend Heyting to provide a formal basis for L. E. J. Brouwer's programme of intuitionism. From a proof-theoretic perspective, Heyting’s calculus is a restriction of classical logic in which the law of excluded middle and double negation elimination have been removed. Excluded middle and double negation elimination can still be proved for some propositions on a case by case basis, however, but do not hold universally as they do with classical logic. The standard explanation of intuitionistic logic is the BHK interpretati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Logic
Classical logic (or standard logic or Frege-Russell logic) is the intensively studied and most widely used class of deductive logic. Classical logic has had much influence on analytic philosophy. Characteristics Each logical system in this class shares characteristic properties: Gabbay, Dov, (1994). 'Classical vs non-classical logic'. In D.M. Gabbay, C.J. Hogger, and J.A. Robinson, (Eds), ''Handbook of Logic in Artificial Intelligence and Logic Programming'', volume 2, chapter 2.6. Oxford University Press. # Law of excluded middle and double negation elimination # Law of noncontradiction, and the principle of explosion # Monotonicity of entailment and idempotency of entailment # Commutativity of conjunction # De Morgan duality: every logical operator is dual to another While not entailed by the preceding conditions, contemporary discussions of classical logic normally only include propositional and first-order logics. Shapiro, Stewart (2000). Classical Logic. In Stanford Encyclop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorites Paradox
The sorites paradox (; sometimes known as the paradox of the heap) is a paradox that results from vague predicates. A typical formulation involves a heap of sand, from which grains are removed individually. With the assumption that removing a single grain does not cause a heap to become a non-heap, the paradox is to consider what happens when the process is repeated enough times that only one grain remains: is it still a heap? If not, when did it change from a heap to a non-heap? The original formulation and variations Paradox of the heap The word ''sorites'' ('' grc-gre, σωρείτης'') derives from the Greek word for 'heap' ('' grc-gre, σωρός''). The paradox is so named because of its original characterization, attributed to Eubulides of Miletus. The paradox is as follows: consider a heap of sand from which grains are removed individually. One might construct the argument, using premises, as follows: :'' grains of sand is a heap of sand'' (Premise 1) :''A heap of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Cresswell
Maxwell John Cresswell (born 19 November 1939) is a New Zealand philosopher and logician, known for his work in modal logic.''Festschrift for Max Cresswell on the occasion of his 65th birthday.'' In: ''Logique et Analyse.'' Number 181, March 2003 (published November 2004). See the introduction by Thomas Forster. Education and career Cresswell received his B.A. in 1960 and M.A. in 1961 from the University of New Zealand and then with the support of a Commonwealth Scholarship attended the Victoria University of Manchester, where he received in 1964 his PhD under the supervision of A. N. Prior. Cresswell's thesis was titled ''General and Specific Logics of Functions of Propositions''. After returning to New Zealand, Cresswell was at the Victoria University of Wellington, from 1963 to 1967 as a lecturer, from 1968 to 1972 as a senior lecturer (also receiving in 1972 Lit.D. from the Victoria University), becoming a reader in 1973, and then a professor from 1974 to 2000, interrupte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagueness
In linguistics and philosophy, a vague predicate is one which gives rise to borderline cases. For example, the English adjective "tall" is vague since it is not clearly true or false for someone of middling height. By contrast, the word "prime" is not vague since every number is definitively either prime or not. Vagueness is commonly diagnosed by a predicate's ability to give rise to the Sorites paradox. Vagueness is separate from ambiguity, in which an expression has multiple denotations. For instance the word "bank" is ambiguous since it can refer either to a river bank or to a financial institution, but there are no borderline cases between both interpretations. Vagueness is a major topic of research in philosophical logic, where it serves as a potential challenge to classical logic. Work in formal semantics has sought to provide a compositional semantics for vague expressions in natural language. Work in philosophy of language has addressed implications of vagueness for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bistability
In a dynamical system, bistability means the system has two stable equilibrium states. Something that is bistable can be resting in either of two states. An example of a mechanical device which is bistable is a light switch. The switch lever is designed to rest in the "on" or "off" position, but not between the two. Bistable behavior can occur in mechanical linkages, electronic circuits, nonlinear optical systems, chemical reactions, and physiological and biological systems. In a conservative force field, bistability stems from the fact that the potential energy has two local minima, which are the stable equilibrium points. These rest states need not have equal potential energy. By mathematical arguments, a local maximum, an unstable equilibrium point, must lie between the two minima. At rest, a particle will be in one of the minimum equilibrium positions, because that corresponds to the state of lowest energy. The maximum can be visualized as a barrier between them. A sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liar Paradox
In philosophy and logic, the classical liar paradox or liar's paradox or antinomy of the liar is the statement of a liar that they are lying: for instance, declaring that "I am lying". If the liar is indeed lying, then the liar is telling the truth, which means the liar just lied. In "this sentence is a lie" the paradox is strengthened in order to make it amenable to more rigorous logical analysis. It is still generally called the "liar paradox" although abstraction is made precisely from the liar making the statement. Trying to assign to this statement, the strengthened liar, a classical binary truth value leads to a contradiction. If "this sentence is false" is true, then it is false, but the sentence states that it is false, and if it is false, then it must be true, and so on. History The Epimenides paradox (circa 600 BC) has been suggested as an example of the liar paradox, but they are not logically equivalent. The semi-mythical seer Epimenides, a Cretan, reportedly stated t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modal Logic
Modal logic is a collection of formal systems developed to represent statements about necessity and possibility. It plays a major role in philosophy of language, epistemology, metaphysics, and natural language semantics. Modal logics extend other systems by adding unary operators \Diamond and \Box, representing possibility and necessity respectively. For instance the modal formula \Diamond P can be read as "possibly P" while \Box P can be read as "necessarily P". Modal logics can be used to represent different phenomena depending on what kind of necessity and possibility is under consideration. When \Box is used to represent epistemic necessity, \Box P states that P is epistemically necessary, or in other words that it is known. When \Box is used to represent deontic necessity, \Box P states that P is a moral or legal obligation. In the standard relational semantics for modal logic, formulas are assigned truth values relative to a ''possible world''. A formula's truth value at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
