Western Philosophy 20th-century philosophy
Name	David Kellogg Lewis
Birth	September 28, 1941 Oberlin, Ohio
Death	October 14, 2001 Princeton, New Jersey
School/tradition	Analytic
Main interests	Logic · Language · Metaphysics Epistemology · Ethics
Notable ideas	Possible worlds · Modal realism
Influenced by	Leibniz · Hume · Carnap · Ryle Quine · Strawson

David Kellogg Lewis (September 28, 1941 – October 14, 2001) is considered to have been one of the leading analytic philosophers of the latter half of the 20th century. Western philosophy is a term that refers to philosophical thinking in the Western or Occidental world, as distinct from Eastern or Oriental philosophies See also [[Analytic philosophy]] and [[Continental philosophy]] The 20th century brought with it upheavals that produced a series of conflicting developments within Philosophy Events 48 BC - Pompey the Great is assassinated on orders of King Ptolemy of Egypt after landing in Egypt. Year 1941 ( MCMXLI) was a Common year starting on Wednesday (the link will display 1941 calendar of the Gregorian calendar. Oberlin is a city in Lorain County, Ohio, United States, to the south and west of Cleveland. Ohio ( is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads Events 1066 - Norman Conquest: Battle of Hastings - In England on Senlac Hill seven miles from Hastings, the forces Year 2001 ( MMI) was a Common year starting on Monday according to the Gregorian calendar. See also Princeton Township New Jersey, Borough of Princeton New Jersey Princeton Borough New Jersey Princeton Township New Jersey this New Jersey ( is a state in the Mid-Atlantic and Northeastern regions of the United States. Analytic philosophy (sometimes analytical philosophy) is a generic term for a style of Philosophy that came to dominate English-speaking countries in the 20th century Logic is the study of the principles of valid demonstration and Inference. A language is a dynamic set of visual auditory or tactile Symbols of Communication and the elements used to manipulate them Metaphysics is the branch of Philosophy investigating principles of reality transcending those of any particular science Epistemology (from Greek επιστήμη - episteme, "knowledge" + λόγος, " Logos " or theory of knowledge Ethics is a major branch of Philosophy, encompassing right conduct and good life Modal realism is the view notably propounded by David Lewis, that Possible worlds are as real as the actual world David Hume (26 April 1711 25 August 1776 Scottish Philosopher, Economist, and Historian is an important figure in Western philosophy Rudolf Carnap ( May 18, 1891 &ndash September 14, 1970) was an influential German -born philosopher who was active in Gilbert Ryle ( 19 August 1900 - 6 October 1976) was a British Philosopher, and a representative of the generation of Willard Van Orman Quine (June 25 1908 Akron, Ohio &ndash December 25 2000 (known to intimates as "Van" Sir Peter Frederick Strawson ( 23 November 1919  &ndash 13 February 2006) was an English philosopher Events 48 BC - Pompey the Great is assassinated on orders of King Ptolemy of Egypt after landing in Egypt. Year 1941 ( MCMXLI) was a Common year starting on Wednesday (the link will display 1941 calendar of the Gregorian calendar. Events 1066 - Norman Conquest: Battle of Hastings - In England on Senlac Hill seven miles from Hastings, the forces Year 2001 ( MMI) was a Common year starting on Monday according to the Gregorian calendar. Analytic philosophy (sometimes analytical philosophy) is a generic term for a style of Philosophy that came to dominate English-speaking countries in the 20th century The twentieth century of the Common Era began on Lewis taught briefly at UCLA and then at Princeton from 1970 until his death. The University of California Los Angeles (generally known as UCLA) is a public research university located in Westwood Los Angeles, California, United Princeton University is a private Coeducational research university located in Princeton, New Jersey. He is also closely associated with Australia, whose philosophical community he visited almost annually for more than thirty years. For a topic outline on this subject see List of basic Australia topics. He is most famous for his theory of modal realism but also made ground-breaking contributions in philosophy of language, philosophy of mind, general metaphysics, epistemology, and philosophical logic. Modal realism is the view notably propounded by David Lewis, that Possible worlds are as real as the actual world Philosophy of language is the reasoned inquiry into the nature origins and usage of Language. Philosophy of mind is the branch of Philosophy that studies the nature of the Mind, Mental events Mental functions mental properties Metaphysics is the branch of Philosophy investigating principles of reality transcending those of any particular science Epistemology (from Greek επιστήμη - episteme, "knowledge" + λόγος, " Logos " or theory of knowledge This article is about Philosophical logic not Philosophy of logic Philosophical logic is the study of the more specifically philosophical aspects of Lewis's best known, and most controversial theory is that there exist an infinite number of concrete and causally isolated parallel universes, of which ours is just one, and which play the role of possible worlds in the analysis of necessity and possibility. The multiverse (or meta-universe) is the hypothetical set of multiple possible Universes (including our universe that together comprise all of Reality. He has also made lasting contributions to an incredible number of fields of philosophy. Indeed, a significant part of contemporary analytic philosophical work betrays the extent of his impact on the field.

Early life and education

Lewis was born in Oberlin, Ohio, to John D. Oberlin is a city in Lorain County, Ohio, United States, to the south and west of Cleveland. Ohio ( is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads Lewis, a Professor of Government at Oberlin College, and Ruth Ewart Kellogg Lewis, a distinguished medieval historian. Oberlin College is a private Liberal arts college in Oberlin Ohio. The formidable intellect for which he was known later in his life was already manifest during his years at Oberlin High School, when he attended college lectures in chemistry. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties He went on to Swarthmore College and spent a year at Oxford (1959-1960), where he was tutored by Iris Murdoch and attended lectures by Gilbert Ryle, H.P. Grice, P.F. Strawson, and J.L. Austin. Swarthmore College is a private, independent, liberal arts college in the United States with an enrollment of about 1500 students Dame Jean Iris Murdoch DBE ( 15 July 1919 &ndash 8 February 1999) was a Dublin -born writer and philosopher Gilbert Ryle ( 19 August 1900 - 6 October 1976) was a British Philosopher, and a representative of the generation of Herbert Paul Grice ( March 13, 1913, Birmingham, England - August 28, 1988, Berkeley California) usually publishing under Sir Peter Frederick Strawson ( 23 November 1919  &ndash 13 February 2006) was an English philosopher John Langshaw Austin ( March 26, 1911 – February 8, 1960) was a British philosopher of language, born in Lancaster and It was his year at Oxford that played a seminal role in his decision to study philosophy, and which made him the quintessentially analytic philosopher that he would soon become. The University of Oxford (informally "Oxford University" or simply "Oxford" located in the city of Oxford, Oxfordshire, England is the Analytic philosophy (sometimes analytical philosophy) is a generic term for a style of Philosophy that came to dominate English-speaking countries in the 20th century Lewis went on to receive his Ph. D from Harvard in 1967, where he studied under W.V.O. Quine, many of whose views he came to repudiate. Willard Van Orman Quine (June 25 1908 Akron, Ohio &ndash December 25 2000 (known to intimates as "Van" It was there that his connection with Australia was first established when he took a seminar with J.J.C. Smart, a leading Australian philosopher. For a topic outline on this subject see List of basic Australia topics. John Jamieson Carswell "Jack" Smart AC (born 1920 often referred to as J "I taught David Lewis," Smart would say in later years, "Or rather, he taught me. "

Early work on convention

Lewis's first monograph was Convention: A Philosophical Study (1969), which is based on his doctoral dissertation and uses concepts of game theory to analyze the nature of social conventions; it won the American Philosophical Association's first Franklin Matchette Prize for the best book published in philosophy by a philosopher under 40 years old. Game theory is a branch of Applied mathematics that is used in the Social sciences (most notably Economics) Biology, Engineering, The American Philosophical Association is the main professional organization for Philosophers in the United States. Lewis claimed that social conventions, such as the convention in most states that one drives on the right (not on the left), the convention that the original caller will re-call if a phone conversation is interrupted, etc. , are solutions to so-called "'co-ordination problems'". Co-ordination problems were at the time of Lewis's book a much under-discussed kind of game-theoretical problem; most of the game-theoretical discussion had circulated around problems where the participants are in conflict, such as the prisoner's dilemma. The Prisoner's Dilemma constitutes a problem in Game theory. It was originally framed by Merrill Flood and Melvin Dresher

Now co-ordination problems are problematic, for, though the participants have common interests, there are several solutions. Sometimes, one of the solutions may be "'salient'" a concept invented by the game-theorist Thomas Schelling (by whom Lewis was much inspired). Thomas Crombie Schelling (born 14 April 1921) is an American Economist and professor of Foreign affairs, National security For example, a co-ordination problem that has the form of a meeting may have a salient solution if there is only one possible spot to meet in town. But in most cases, we must rely on what Lewis calls "precedent" in order to get a salient solution. If both participants know that a particular co-ordination problem, say "which side should we drive on?" has been solved in the same way numerous times before, both know that both know this, both know that both know that both know this, etc. (this particular state Lewis calls common knowledge, and it has since been much discussed by philosophers and game theorists), then they will easily solve the problem. Common knowledge is a special kind of Knowledge for a group of agents There is common knowledge of p in a group of agents G That they have solved the problem successfully will be seen by even more people, and thus the convention will spread in society. A convention is thus a behavioural regularity that sustains itself because it serves the interests of everyone involved. Another important feature of a convention is that a convention could be entirely different: one could just as well drive on the left; it is more or less arbitrary that one drives on the right in the USA, for example.

Lewis's main goal in the book, however, wasn't simply to provide an account of convention but rather to investigate the "platitude that language is ruled by convention" (Convention, p. 1. ) The last two chapters of the book (Signalling Systems and Conventions of Language; cf. also "Languages and Language", 1975) make the case that the use of a language in a population consists of conventions of truthfulness and trust among members of the population. Lewis recasts in this framework notions as those of truth and analyticity, claiming that they are better understood as relations between sentences and a language, rather than as properties of sentences.

Work on counterfactuals and modal realism

Lewis went on to publish Counterfactuals (1973), which contained an analysis of counterfactual conditionals in terms of the theory of possible worlds. He had already proposed it in some of his earlier papers - "Counterpart Theory and Quantified Modal Logic" (1968), "Anselm and Actuality" (1970), and "Counterparts of Persons and their Bodies" (1971). In spite of significant technical advantages promised by this approach, the theory was widely considered to be too implausible to be taken literally, as Lewis urged it should be. Most often the idea that there exists an infinite number of causally isolated universes, each as real as our own but different from it in some way, and that furthermore that alluding to objects in this universe is necessary in order to explain what makes certain counterfactual statements true but not others, meets with what Lewis calls the "incredulous stare" (Lewis, OPW, 2005, pg. 135-137). Lewis defends and elaborates his theory of extreme modal realism, while insisting that there is nothing extreme about it, in On the Plurality of Worlds (1986). Modal realism is the view notably propounded by David Lewis, that Possible worlds are as real as the actual world On the Plurality of Worlds (1986 is an influential book by the Philosopher David Lewis that defends the thesis of Modal realism, "the thesis Lewis acknowledges that his theory is contrary to common sense, but believes that its advantages far outweigh this disadvantage, and that therefore we should not be hesitant to pay this price.

According to Lewis, what makes a counterfactual conditional of the form 'Had I made that shot our team would have won the game. A counterfactual conditional, Subjunctive conditional or remote conditional is a conditional (or "if-then" statement indicating what would be ' true is that there is a world, as concrete as ours and significantly similar to it, in which my counterpart makes rather than misses the shot and the counterpart of our team wins the game. Had there been a world even more similar to ours in which my counterpart makes the shot but the counterpart of our team still loses the counterfactual would have been false. When we speak of counterfactual possibilities we speak of what is the case in some possible world or worlds. "Actual", according to Lewis, is merely an indexical label we give to a world when we locate ourselves in it. Things are necessarily true when they are true in all possible worlds. (Note that Lewis is not the first one to speak of possible worlds in this context. Leibniz and C. I. Lewis, for example, both speak of possible worlds as a way of thinking about possibility and necessity, and some of David Kaplan's early work is on the counterpart theory. Clarence Irving Lewis ( April 12, 1883 Stoneham Massachusetts - February 3, 1964 Cambridge Massachusetts) usually David Kaplan is the name of David Kaplan (philosopher (born 1933 an American philosopher David Kaplan (film critic Counterpart theory ( CT) is a theoretical framework It uses the counterpart relation (hereafter C-relation to replace the identity relation between objects in different Lewis's original suggestion was that all possible worlds are equally concrete, and the world in which we find ourselves is no more real than any other possible world. )

This theory has faced a number of criticisms. In particular, it is not clear how we could know what goes on in other worlds. After all, they are causally disconnected from ours; we can't look into them to see what is going on there. ^[1] A related objection is that, while people are concerned with what they could have done, they are not concerned with what some people in other worlds, no matter how similar to them, do. As Saul Kripke once put it, a presidential candidate could not care less whether someone else, in another world, wins an election, but with whether he himself could have won it (Kripke 1980, p. Saul Aaron Kripke (born on November 13, 1940 in Bay Shore New York) is an American philosopher and Logician now Emeritus 45). A more basic criticism is that introducing so many entities into our ontology violates the maxim of Occam's razor, which tells us not to multiply theoretical entities beyond what is necessary to explain the facts our theories aim to explain. In Philosophy, ontology (from the Greek, genitive: of being (part Occam's razor (sometimes spelled Ockham's razor) is a principle attributed to the 14th-century English Logician and Franciscan Friar, One of the main concerns of Lewis (1986) is to address some of these criticisms.

Possible worlds are employed in the work of Saul Kripke (Naming and Necessity, 1972, 1980), Gideon Rosen ("Modal Fictionalism", 1990), Nathan Salmon (Reference and Essence, 1979), Robert Stalnaker (Inquiry, 1984), and many others, but not in the concrete sense propounded by Lewis. Saul Aaron Kripke (born on November 13, 1940 in Bay Shore New York) is an American philosopher and Logician now Emeritus Naming and Necessity is a book by the philosopher Saul Kripke that was first published in 1980 Nathan U Salmon (né Nathan Salmon Ucuzoglu 1951 - is an American philosopher in the analytic tradition specializing in Philosophy of language Robert Culp Stalnaker is Laurance S Rockefeller Professor of Philosophy at the Massachusetts Institute of Technology. While none of these alternative approaches has found anything near universal acceptance, very few philosophers accept Lewis's particular brand of modal realism.

Works

Convention: A Philosophical Study (1969; Harvard University Press) Counterfactuals (1973 [revised printing 1986]; Blackwell & Harvard U. P. ) Semantic Analysis: Essays Dedicated to Stig Kanger on His Fiftieth Birthday (1974; Reidel)) On the Plurality of Worlds (1986; Blackwell)

Lewis published five volumes containing 99 papers - almost all of the papers he published during his lifetime. These papers discuss his counterfactual theory of causation, the concept of semantic score, a contextualist analysis of knowledge, and a dispositional theory of value.

• Philosophical Papers, Vol. I (1983) includes his early work on counterpart theory, and the philosophy of language and of mind;
• Philosophical Papers, Vol. Counterpart theory ( CT) is a theoretical framework It uses the counterpart relation (hereafter C-relation to replace the identity relation between objects in different Philosophy of language is the reasoned inquiry into the nature origins and usage of Language. Philosophy of mind is the branch of Philosophy that studies the nature of the Mind, Mental events Mental functions mental properties II (1986) includes his work on counterfactuals, causation, and decision theory. A counterfactual conditional, Subjunctive conditional or remote conditional is a conditional (or "if-then" statement indicating what would be Decision theory in Mathematics and Statistics is concerned with identifying the Values uncertainties and other issues relevant in a given Its preface discusses "Humean Supervenience," the name Lewis gave to his overarching philosophical project;
• Papers in Philosophical Logic (1998);
• Papers in Metaphysics and Epistemology (1999) contains "Elusive Knowledge" and "Naming the Colours," honored by being reprinted in the Philosopher's Annual for the year they were first published;
• Papers in Ethics and Social Philosophy. This article is about Philosophical logic not Philosophy of logic Philosophical logic is the study of the more specifically philosophical aspects of Metaphysics is the branch of Philosophy investigating principles of reality transcending those of any particular science Epistemology (from Greek επιστήμη - episteme, "knowledge" + λόγος, " Logos " or theory of knowledge Ethics is a major branch of Philosophy, encompassing right conduct and good life

Lewis's last monograph, Parts of Classes (1991), on the foundations of mathematics, sketched a reduction of set theory and Peano arithmetic to mereology and plural quantification. Foundations of mathematics is a term sometimes used for certain fields of Mathematics, such as Mathematical logic, Axiomatic set theory, Proof theory In Mathematical logic, the Peano axioms, also known as the Dedekind-Peano axioms or the Peano postulates, are a set of Axioms for the Natural In Mathematical logic, mereology is a collection of axiomatic First-order theories dealing with parts and their respective wholes In Mathematics and logic, plural quantification is the theory that an individual Variable x may take on Very soon after its publication, Lewis became dissatisfied with some aspects of its argument; it is currently out of print.

At Princeton, Lewis was a gifted mentor of young philosophers, and trained dozens of successful figures in the field, including several current Princeton faculty members, as well as people now teaching at a number of the leading programs in the U. S. Among his most prominent students are L. A. Paul, Cian Dorr, Philip Bricker, David Velleman, and Peter Railton. J David Velleman is a Professor of Philosophy at New York University. Peter Albert Railton (born 23 May 1950) is John Stephenson Perrin Professor of Philosophy at the University of Michigan Ann Arbor. His direct and indirect influence is evident in the work of many prominent philosophers of the current generation.

Later life and death

David K. Lewis in Australia, where he liked to visit. For a topic outline on this subject see List of basic Australia topics.

Lewis suffered from severe diabetes for much of his life, which eventually grew worse and led into kidney failure. Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc The kidneys are complicated organs that have numerous biological roles In July of 2000 he received a kidney transplant from his wife Stephanie. Kidney transplantation or renal transplantation is the Organ transplant of a Kidney in a patient with End-stage renal disease. The transplant allowed him to work and travel for another year, before he died suddenly and unexpectedly from further complications of his diabetes, on 14 October 2001. Events 1066 - Norman Conquest: Battle of Hastings - In England on Senlac Hill seven miles from Hastings, the forces Year 2001 ( MMI) was a Common year starting on Monday according to the Gregorian calendar. ^[2]

Since his death a number of posthumous papers have been published, on topics ranging from truth and causation to philosophy of physics. Lewisian Themes, a collection of papers on his philosophy, was published in 2004.

Selected works

"Mad pain and Martian pain. Mad Pain and Martian Pain is a philosophical article written by David Kellogg Lewis. " Readings in the Philosophy of Psychology Vol. I. N. Block, ed. Harvard University Press (1980): pp. 216-222.

"New Work for a Theory of Universals. " Australasian Journal of Philosophy 61 (1983): pp. 343-77.

"Elusive Knowledge", Australasian Journal of Philosophy, 74/4 (1996): pp. 549-567.

References

External links

• David Lewis: Bibliography