Willard Van Orman Quine (/kwaɪn/KWYNE; known to his friends as "Van";[3] June 25, 1908 – December 25, 2000) was an American philosopher andlogician in theanalytic tradition, recognized as "one of the most influential philosophers of the twentieth century".[4] He was the Edgar Pierce Chair of Philosophy atHarvard University from 1956 to 1978.
Quine was a teacher of logic andset theory. He was famous for his position thatfirst-order logic is the only kind worthy of the name, and developed his own system of mathematics and set theory, known asNew Foundations. In thephilosophy of mathematics, he and his Harvard colleagueHilary Putnam developed theQuine–Putnam indispensability argument, an argument for thereality of mathematical entities.[5] He was the main proponent of the view that philosophy is notconceptual analysis, but continuous with science; it is the abstract branch of the empirical sciences. This led to his famous quip that "philosophy of science is philosophy enough".[6] He led a "systematic attempt to understand science from within the resources of science itself"[7] and developed an influentialnaturalized epistemology that tried to provide "an improved scientific explanation of how we have developed elaborate scientific theories on the basis of meager sensory input".[7] He also advocated holism in science, known as theDuhem–Quine thesis.
His major writings include the papers "On What There Is" (1948), which elucidatedBertrand Russell'stheory of descriptions and contains Quine's famous dictum ofontological commitment, "To be is to be the value of avariable", and "Two Dogmas of Empiricism" (1951), which attacked the traditionalanalytic-synthetic distinction and reductionism, undermining the then-popularlogical positivism, advocating instead a form ofsemantic holism andontological relativity. They also include the booksThe Web of Belief (1970), which advocates a kind ofcoherentism, andWord and Object (1960), which further developed these positions and introduced Quine's famousindeterminacy of translation thesis, advocating abehavioristtheory of meaning.
Quine's parents were Robert Cloyd Quine and Harriet Ellis Van Orman. Quine grew up inAkron, Ohio, where he lived with his parents and older brother Robert Cloyd. His father was a manufacturing entrepreneur (founder of the Akron Equipment Company, which produced tire molds) and his mother was a schoolteacher andhousewife.[8][3] Quine became an atheist around the age of 9[9] and remained one for the rest of his life.[10]
Quine received hisB.A.summa cum laude in mathematics fromOberlin College in 1930, and his Ph.D. in philosophy fromHarvard University in 1932. His thesis supervisor wasAlfred North Whitehead. He was then appointed aHarvard Junior Fellow, which excused him from having to teach for four years. During the academic year 1932–33, he travelled in Europe thanks to a Sheldon Fellowship, meeting Polish logicians (includingJan Łukasiewicz,Stanislaw Lesniewski andAlfred Tarski) and members of theVienna Circle (includingRudolf Carnap), as well as thelogical positivistA. J. Ayer.[3] It was inPrague that Quine developed a passion for philosophy, thanks to Carnap, whom he called his "true and onlymaître à penser".[11]
Quine arranged forTarski to be invited to the September 1939Unity of Science Congress in Cambridge, for which the Jewish Tarski sailed on the last ship to leaveDanzig beforeNazi Germany invaded Poland and triggeredWorld War II. Tarski survived the war and worked another 44 years in the US. During the war, Quine lectured on logic inBrazil, in Portuguese, and served in theUnited States Navy in amilitary intelligence role, deciphering messages from German submarines, and reaching the rank of lieutenant commander.[3] Quine could lecture in French, German, Italian, Portuguese, and Spanish as well as his native English.
He had four children by two marriages.[3] GuitaristRobert Quine was his nephew.
Quine was politically conservative, but the bulk of his writing was in technical areas of philosophy removed from direct political issues.[12] He did, however, write in defense of several conservative positions: for example, he wrote in defense ofmoral censorship;[13] while, in his autobiography, he made some criticisms of American postwar academics.[14][15]
At Harvard, Quine helped supervise the Harvardgraduate theses of, among others,David Lewis,Gilbert Harman,Dagfinn Føllesdal,Hao Wang,Hugues LeBlanc,Henry Hiz andGeorge Myro. For the academic year 1964–1965, Quine was a fellow on the faculty in the Center for Advanced Studies atWesleyan University.[16] In 1980Quine received anhonorary doctorate from the Faculty of Humanities atUppsala University, Sweden.[17]
Quine's student Dagfinn Føllesdal noted that Quine suffered from memory loss towards his final years. The deterioration of his short-term memory was so severe that he struggled to continue following arguments. Quine also had considerable difficulty in his project to make the desired revisions toWord and Object. Before dying, Quine noted toMorton White: "I do not remember what my illness is called, Althusser orAlzheimer, but since I cannot remember it, it must be Alzheimer." He died from the illness on Christmas Day in 2000.[18][19]
Quine's Ph.D. thesis and early publications were onformal logic andset theory. Only after World War II did he, by virtue of seminal papers onontology,epistemology and language, emerge as a major philosopher. By the 1960s, he had worked out his "naturalized epistemology" whose aim was to answer all substantive questions of knowledge and meaning using the methods and tools of the natural sciences. Quine roundly rejected the notion that there should be a "first philosophy," a theoretical standpoint somehow prior to natural science and capable of justifying it. These views are intrinsic to hisnaturalism.
Like the majority of analytic philosophers, who were mostly interested in systematic thinking, Quine evinced little interest in thephilosophical canon: only once did he teach a course in the history of philosophy, onDavid Hume, in 1946.[20][clarification needed]
Over the course of his career, Quine published numerous technical and expository papers on formal logic, some of which are reprinted in hisSelected Logic Papers and inThe Ways of Paradox. His most well-known collection of papers isFrom A Logical Point of View. Quine confined logic to classical bivalentfirst-order logic, hence to truth and falsity under any (nonempty)universe of discourse. Hence the following were not logic for Quine:
Quine wrote three undergraduate texts on formal logic:
Mathematical Logic is based on Quine's graduate teaching during the 1930s and 1940s. It shows that much of whatPrincipia Mathematica took more than 1000 pages to say can be said in 250 pages. The proofs are concise, even cryptic. The last chapter, onGödel's incompleteness theorem andTarski's indefinability theorem, along with the article Quine (1946), became a launching point forRaymond Smullyan's later lucid exposition of these and related results.
Quine's work in logic gradually became dated in some respects. Techniques he did not teach and discuss includeanalytic tableaux,recursive functions, andmodel theory. His treatment ofmetalogic left something to be desired. For example,Mathematical Logic does not include any proofs ofsoundness andcompleteness. Early in his career, the notation of his writings on logic was often idiosyncratic. His later writings nearly always employed the now-dated notation ofPrincipia Mathematica. Set against all this are the simplicity of his preferred method (as exposited in hisMethods of Logic) for determining the satisfiability of quantified formulas, the richness of his philosophical and linguistic insights, and the fine prose in which he expressed them.
Most of Quine's original work in formal logic from 1960 onwards was on variants of hispredicate functor logic, one of several ways that have been proposed for doing logic withoutquantifiers. For a comprehensive treatment of predicate functor logic and its history, see Quine (1976). For an introduction, see ch. 45 of hisMethods of Logic.
Quine was very warm to the possibility that formal logic would eventually be applied outside of philosophy and mathematics. He wrote several papers on the sort ofBoolean algebra employed inelectrical engineering, and withEdward J. McCluskey, devised theQuine–McCluskey algorithm of reducingBoolean equations to a minimum covering sum ofprime implicants.
While his contributions to logic include elegant expositions and a number of technical results, it is inset theory that Quine was most innovative. He always maintained that mathematics required set theory and that set theory was quite distinct from logic. He flirted withNelson Goodman'snominalism for a while[21] but backed away when he failed to find a nominalist grounding of mathematics.[22]
Over the course of his career, Quine proposed three axiomatic set theories.
All three set theories admit a universal class, but since they are free of anyhierarchy oftypes, they have no need for a distinct universal class at each type level.
Quine's set theory and its background logic were driven by a desire to minimize posits; each innovation is pushed as far as it can be pushed before further innovations are introduced. For Quine, there is but one connective, theSheffer stroke, and one quantifier, theuniversal quantifier. All polyadicpredicates can be reduced to one dyadic predicate, interpretable as set membership. His rules of proof were limited tomodus ponens and substitution. He preferredconjunction to eitherdisjunction or theconditional, because conjunction has the least semantic ambiguity. He was delighted to discover early in his career that all of first order logic and set theory could be grounded in a mere two primitive notions:abstraction andinclusion. For an elegant introduction to the parsimony of Quine's approach to logic, see his "New Foundations for Mathematical Logic", ch. 5 in hisFrom a Logical Point of View.
Quine has had numerous influences on contemporarymetaphysics. He coined the term "abstract object".[23]
In his famous essay "On What There Is", he connected each of the three main metaphysical ontological positions—realism/conceptualism/nominalism—with one of three dominant schools in the modernphilosophy of mathematics:logicism,intuitionism, andformalism respectively. In the same work, he coined the term "Plato's beard" to refer to the problem ofempty names:
Suppose now that two philosophers, McX and I, differ overontology. Suppose McX maintains there is something which I maintain there is not. McX can, quite consistently with his own point of view, describe our difference of opinion by saying that I refuse to recognize certain entities ... WhenI try to formulate our difference of opinion, on the other hand, I seem to be in a predicament. I cannot admit that there are some things which McX countenances and I do not, for in admitting that there are such things I should be contradicting my own rejection of them ... This is the old Platonic riddle of nonbeing. Nonbeing must in some sense be, otherwise what is it that there is not? This tangled doctrine might be nicknamedPlato's beard; historically it has proved tough, frequently dulling the edge of Occam’s razor.[24][25]
Quine was unsympathetic, however, to the claim that saying 'X does not exist' is a tacit acceptance of X's existence and, thus, a contradiction. Appealing toBertrand Russell and his theory of "singular descriptions", Quine explains how Russell was able to make sense of "complex descriptive names" ('the present King of France', 'the author ofWaverly', etc.) by thinking about them as merely "fragments of the whole sentences". For example, 'The author ofWaverly was a poet' becomes 'some thing is such that it is the author ofWaverly and was a poet, and nothing else is such that it is the author ofWaverly'.[26]
Using this sort of analysis with the word 'Pegasus' (that which Quine is wanting to assert does not exist), he turns Pegasus into a description. Turning the word 'Pegasus' into a description is to turn 'Pegasus' into a predicate, to use a term ofFirst-order logic: i.e. a property. As such, when we say 'Pegasus', we are really saying 'the thing that is Pegasus' or 'the thing thatPegasizes'. This introduces, to use another term from logic, bound variables (ex: 'everything', 'something,' etc.) As Quine explains, bound variables, "far from purporting to be names specifically...do not purport to be names at all: they refer to entities generally, with a kind of studied ambiguity peculiar to themselves."[27]
Putting it another way, to say 'I hate everything' is a very different statement than saying 'I hate Bertrand Russell', because the words 'Bertrand Russell' are aproper name that refer to a very specific person. Whereas the word 'everything' is a placeholder. It does not refer to a specific entity or entities. Quine is able, therefore, to make a meaningful claim about Pegasus' nonexistence for the simple reason that the placeholder (a thing) happens to be empty. It just so happens that the world does not contain a thing that is such that it is winged and it is a horse.
In the 1930s and 40s, discussions withRudolf Carnap,Nelson Goodman andAlfred Tarski, among others, led Quine to doubt the tenability of the distinction between "analytic" statements[28]—those true simply by the meanings of their words, such as "No bachelor is married"— and "synthetic" statements, those true or false by virtue of facts about the world, such as "There is a cat on the mat."[29] This distinction was central tological positivism. Although Quine is not normally associated withverificationism, some philosophers believe the tenet is not incompatible with his general philosophy of language, citing his Harvard colleagueB. F. Skinner and his analysis of language inVerbal Behavior.[30] But Quine believes, with all due respect to his "great friend"[31] Skinner, that the ultimate reason is to be found in neurology and not in behavior. For him, behavioral criteria establish only the terms of the problem, the solution of which, however, lies inneurology.[31]
Like other analytic philosophers before him, Quine accepted thedefinition of "analytic" as "true in virtue of meaning alone." Unlike them, however, he concluded that ultimately the definition wascircular. In other words, Quine accepted that analytic statements are those that are true by definition, then argued that the notion of truth by definition was unsatisfactory.
Quine's chief objection to analyticity is with the notion ofcognitive synonymy (sameness of meaning). He argues that analytical sentences are typically divided into two kinds; sentences that are clearly logically true (e.g. "no unmarried man is married") and the more dubious ones; sentences like "no bachelor is married." Previously it was thought that if you can prove that there is synonymity between "unmarried man" and "bachelor," you have proved that both sentences are logically true and therefore self evident. Quine however gives several arguments for why this is not possible, for instance that "bachelor" in some contexts means aBachelor of Arts, not an unmarried man.[32]
ColleagueHilary Putnam called Quine'sindeterminacy of translation thesis "the most fascinating and the most discussed philosophical argument sinceKant'sTranscendental Deduction of the Categories".[33] The central theses underlying it areontological relativity and the relateddoctrine ofconfirmation holism. The premise of confirmationholism is that all theories (and the propositions derived from them) areunder-determined by empirical data (data,sensory-data, evidence); although some theories are not justifiable, failing to fit with the data or being unworkably complex, there are many equally justifiable alternatives. While theGreeks' assumption that (unobservable)Homeric gods exist is false and our supposition of (unobservable)electromagnetic waves is true, both are to be justified solely by their ability to explain our observations.
Thegavagaithought experiment tells about a linguist, who tries to find out, what the expressiongavagai means, when uttered by a speaker of a yet unknown, native language upon seeing a rabbit. At first glance, it seems thatgavagai simply translates withrabbit. Now, Quine points out that the background language and its referring devices might fool the linguist here, because he is misled in a sense that he always makes direct comparisons between the foreign language and his own. However, when shoutinggavagai, and pointing at a rabbit, the natives could as well refer to something likeundetached rabbit-parts, orrabbit-tropes and it would not make any observable difference. The behavioural data the linguist could collect from the native speaker would be the same in every case, or to reword it, several translation hypotheses could be built on the same sensoric stimuli.
Quine concluded his "Two Dogmas of Empiricism" as follows:
As an empiricist I continue to think of the conceptual scheme of science as a tool, ultimately, for predicting future experience in the light of past experience. Physical objects are conceptually imported into the situation as convenient intermediaries not by definition in terms of experience, but simply as irreducible posits comparable, epistemologically, to the gods of Homer …. For my part I do,qua lay physicist, believe in physical objects and not in Homer's gods; and I consider it a scientific error to believe otherwise. But in point of epistemological footing, the physical objects and the gods differ only in degree and not in kind. Both sorts of entities enter our conceptions only as cultural posits.
Quine's ontologicalrelativism (evident in the passage above) led him to agree withPierre Duhem that for any collection ofempirical evidence, there would always be many theories able to account for it, known as theDuhem–Quine thesis. However, Duhem'sholism is much more restricted and limited than Quine's. For Duhem,underdetermination applies only tophysics or possibly tonatural science, while for Quine it applies to all of human knowledge. Thus, while it is possible to verify orfalsify whole theories, it is not possible to verify or falsify individual statements. Almost any particular statement can be saved, given sufficiently radical modifications of the containing theory. For Quine, scientific thought forms acoherent web in which any part could be altered in the light of empirical evidence, and in which no empirical evidence could force the revision of a given part.
Theproblem of non-referring names is an old puzzle in philosophy, which Quine captured when he wrote,
A curious thing about the ontological problem is its simplicity. It can be put into three Anglo-Saxon monosyllables: 'What is there?' It can be answered, moreover, in a word—'Everything'—and everyone will accept this answer as true.[24]
More directly, the controversy goes:
How can we talk aboutPegasus? To what does the word 'Pegasus' refer? If our answer is, 'Something', then we seem to believe in mystical entities; if our answer is, 'nothing', then we seem to talk about nothing and what sense can be made of this? Certainly when we said that Pegasus was a mythological winged horse we make sense, and moreover we speak the truth! If we speak the truth, this must be truthabout something. So we cannot be speaking of nothing.
Quine resists the temptation to say that non-referring terms are meaningless for reasons made clear above. Instead he tells us that we must first determine whether our terms refer or not before we know the proper way to understand them. However,Czesław Lejewski criticizes this belief for reducing the matter to empirical discovery when it seems we should have a formal distinction between referring and non-referring terms or elements of our domain. Lejewski writes further:
This state of affairs does not seem to be very satisfactory. The idea that some of our rules of inference should depend on empirical information, which may not be forthcoming, is so foreign to the character of logical inquiry that a thorough re-examination of the two inferences [existential generalization and universal instantiation] may prove worth our while.
Lejewski then goes on to offer a description offree logic, which he claims accommodates an answer to the problem.
Lejewski also points out that free logic additionally can handle the problem of the empty set for statements like. Quine had considered the problem of the empty set unrealistic, which left Lejewski unsatisfied.[34]
The notion ofontological commitment plays a central role in Quine's contributions to ontology.[35][36] A theory is ontologically committed to an entity if that entity must exist in order for the theory to be true.[37] Quine proposed that the best way to determine this is by translating the theory in question intofirst-order predicate logic. Of special interest in this translation are the logical constants known asexistential quantifiers ('∃'), whose meaning corresponds to expressions like "there exists..." or "for some...". They are used tobind the variables in the expression following the quantifier.[38] The ontological commitments of the theory then correspond to the variables bound by existential quantifiers.[39] For example, the sentence "There are electrons" could be translated as "∃xElectron(x)", in which the bound variablex ranges over electrons, resulting in an ontological commitment to electrons.[37] This approach is summed up by Quine's famous dictum that "[t]o be is to be the value of a variable".[40] Quine applied this method to various traditional disputes in ontology. For example, he reasoned from the sentence "There are prime numbers between 1000 and 1010" to an ontological commitment to the existence of numbers, i.e.realism about numbers.[40] This method by itself is not sufficient for ontology since it depends on a theory in order to result in ontological commitments. Quine proposed that we should base our ontology on our best scientific theory.[37] Various followers of Quine's method chose to apply it to different fields, for example to "everyday conceptions expressed in natural language".[41][42]
Inphilosophy of mathematics, he and his Harvard colleagueHilary Putnam developed theQuine–Putnam indispensability thesis, an argument for thereality of mathematical entities.[5]
The form of the argument is as follows.
The justification for the first premise is the most controversial. Both Putnam and Quine invokenaturalism to justify the exclusion of all non-scientific entities, and hence to defend the "only" part of "all and only". The assertion that "all" entities postulated in scientific theories, including numbers, should be accepted as real is justified byconfirmation holism. Since theories are not confirmed in a piecemeal fashion, but as a whole, there is no justification for excluding any of the entities referred to in well-confirmed theories. This puts thenominalist who wishes to exclude the existence ofsets andnon-Euclidean geometry, but to include the existence ofquarks and other undetectable entities of physics, for example, in a difficult position.[43]
Just as he challenged the dominant analytic–synthetic distinction, Quine also took aim at traditionalnormativeepistemology. According to Quine, traditional epistemology tried to justify the sciences, but this effort (as exemplified byRudolf Carnap) failed, and so we should replace traditional epistemology with an empirical study of what sensory inputs produce what theoretical outputs:[44]
Epistemology, or something like it, simply falls into place as a chapter of psychology and hence of natural science. It studies a natural phenomenon, viz., a physical human subject. This human subject is accorded a certain experimentally controlled input—certain patterns of irradiation in assorted frequencies, for instance—and in the fullness of time the subject delivers as output a description of the three-dimensional external world and its history. The relation between the meager input and the torrential output is a relation that we are prompted to study for somewhat the same reasons that always prompted epistemology: namely, in order to see how evidence relates to theory, and in what ways one's theory of nature transcends any available evidence... But a conspicuous difference between old epistemology and the epistemological enterprise in this new psychological setting is that we can now make free use of empirical psychology.[45]
As previously reported, in other occasions Quine used the term "neurology" instead of "empirical psychology".[31]
Quine's proposal is controversial among contemporary philosophers and has several critics, withJaegwon Kim the most prominent among them.[46]
In my third year of high school I walked often with my new Jamaican friends, Fred and Harold Cassidy, trying to convert them from their Episcopalian faith to atheism.
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