Clarence Irving Lewis
Encyclopedia
Clarence Irving Lewis usually cited as C. I. Lewis, was an American academic philosopher and the founder of conceptual pragmatism. First a noted logician, he later branched into epistemology, and during the last 20 years of his life, he wrote much on ethics
.
. His father was a skilled worker in a shoe factory, and Lewis grew up in relatively humble circumstances. He discovered philosophy at age 13, when reading about the Greek pre-Socratics, Anaxagoras
and Heraclitus
in particular. The first work of philosophy Lewis recalled studying was a short history of Greek philosophy
by Marshall. Immanuel Kant
proved a major lifelong influence on Lewis's thinking. In his article "Logic and Pragmatism," Lewis wrote: "Nothing comparable in importance happened [in my life] until I became acquainted with Kant... Kant compelled me. He had, so I felt, followed scepticism to its inevitable last stage, and laid the foundations where they could not be disturbed."
In 1905, Harvard College
awarded Lewis the A.B. after a mere three years of study, during which time he supported himself with part-time jobs. He then taught English for one year in a Quincy MA high school, then two years at the University of Colorado
. In 1906, he married Mable Maxwell Graves. In 1908, Lewis returned to Harvard and began a Ph.D in philosophy, which he completed in a mere two years. He then taught philosophy at the University of California
, 1911–20, after which he returned again to Harvard, where he taught until his 1953 retirement, eventually filling the Edgar Pierce Chair of Philosophy. In 1929, he was elected to the American Academy of Arts and Sciences
. In 1933, he presided over the American Philosophical Association
. For the academic year 1959-1960, he was a Fellow on the faculty in the Center for Advanced Studies at Wesleyan University
.
, and is arguably the founder of modern philosophical logic
. In 1912, two years after the publication of the first volume of Principia Mathematica
, Lewis began publishing articles taking exception to
Principia' s pervasive use of material implication, more specifically, to Bertrand Russell
's reading of a→b as "a implies b." Lewis restated this criticism in his reviews of both editions of PM. Lewis's reputation as a promising young logician was soon assured.
Material implication allows a true consequent to follow from a false antecedent. Lewis proposed to replace material implication with strict implication, such that a false antecedent can never strictly imply a true consequent. This strict implication was not primitive, but defined in terms of negation
, conjunction
, and a prefixed unary intensional
modal operator
,
. Let X be a formula with a classical bivalent truth value. Then 
X can be read as "X is possibly true" (or false, as the case may be). Lewis then defined "A strictly implies B" as "
(A
B)". Lewis's strict implication is now a historical curiosity, but the formal modal logic
in which he grounded that notion is the ancestor of all modern work on the subject. Lewis's
notation is still standard, but current practice usually takes its dual, 
("necessity"), as primitive and 
as defined, in which case "A strictly implies B" is simply written as 
(A→B).
His first logic text, A Survey of Symbolic Logic (1918), went out of print after selling only several hundred copies. At the time of its publication, it included the only discussion in English of the logical writings of Charles Peirce and only the second, after Russell's monograph of 1900, on Leibniz. While the modal logic
of A Survey was soon proved inconsistent, Lewis went on to devise the modal systems S1 to S5, and to set these out in Symbolic Logic (1932) as possible formal analyses of the alethic modalities. Lewis mildly preferred S2 over the others; the amended modal system of A Survey was S3. But it is S4 and S5
that have generated sustained interest, mathematical as well as philosophical, down to the present day. S4 and S5 are the beginning of what is now called normal modal logic
. On Lewis's strict implication and his modal systems S1-S5, see Hughes and Cresswell (1996: chpt. 11).
While many saw Lewis as kin to the logical empiricists, he was never truly comfortable in such company because he declined to divorce experience from cognition. Positivism rejected value as lacking cognitive significance, also rejecting the analysis of experience in favor of physicalism. Both rejections struck him as regrettable. Indeed his growing awareness of the pragmatic tradition led him in the opposite direction. For Lewis, it is only within experience that anything can have significance for anything, and thus he came to see value as a way of representing the significance of knowledge for future conduct. These convictions led him to reflect on the differences between pragmatism
and positivism
, and on the cognitive structure of value experiences.
Lewis agreed that pragmatism
committed one to the Peircean pragmatic test. But in a 1930 essay, "Pragmatism and Current Thought," he maintained that this commitment can be taken in either of two directions. One direction emphasises the subjectivity of experience. The other direction, and the one he took in 'his (1929), began with the Peirce's limitation of meaning to that which makes a verifiable difference in experience. Hence concepts are abstractions in which "the immediate is precisely that element which must be left out." But this claim must be properly understood. An operational account of concepts mainly eliminates the ineffable: "If your hours are felt as twice as long as mine, your pounds twice as heavy, that makes no difference, which can be tested, in our assignment of physical properties to things." Hence a concept is but a relational pattern. But it does not follow that one ought to discard the world as it is experienced:
Thus knowledge begins and ends in experience, keeping in mind that the beginning and ending experiences differ. Knowledge of something requires that the verifying experience be actually experienced. Thus for the pragmatist, verifiability as an operational definition (or test) of the empirical meaning of a statement requires that the speaker know how to apply the statement, and when not to apply it, and be able to trace the consequences of the statement in situations both real and hypothetical.
Lewis firmly objected to the positivist conception of value statements as devoid of cognitive content, as merely expressive. For a pragmatist, all judgements are implicitly value judgements. Lewis (1946) sets out both his conception of sense meaning, and his thesis that valuation is a form of empirical cognition.
In his essay "Logical Positivism and Pragmatism," Lewis revealed his disagreement with verificationism by comparing it unfavorably with his preferred pragmatic conception of empirical meaning. From the outset, he saw both pragmatism
and logical positivism
as forms of empiricism
. At first glance, it would seem that the pragmatic conception of meaning, despite its different formulation and its focus on action, very much resembles the logical positivist verification requirement. Nevertheless, Lewis argued that there is a deep difference between the two: pragmatism ultimately grounds meaning on conceivable experience, while positivism reduces the relation between meaning and experience to a matter of logical form
.
For Lewis, the positivist conception of meaning omits precisely what a pragmatist would count as empirical meaning. Specifying which observation sentences follow from a given sentence helps us determine the empirical meaning of the given sentence only if the observation sentences themselves have an already understood meaning in terms of the specific qualities of experience to which the predicates of the observation sentences refer. Thus Lewis saw the logical positivists as failing to distinguish between "linguistic" meaning, namely the logical relations among terms, and "empirical" meaning, namely the relation expressions have to experience. (In the well-known terminology of Carnap and Charles W. Morris
, empirical meaning falls under pragmatics
, linguistic meaning
under semantics
.) For Lewis, the logical positivist shuts his eyes to precisely that which properly confirms a sentence, namely the content of experience.
s, a belated assessment that is the major theme of Murphey (2005).
, which he did not live to complete. These drafts are included in the Lewis papers held at Stanford University.
Lewis (1947) contains two chapters on esthetics and the philosophy of art. He was the first to employ the term "qualia
", popularized by his student Nelson Goodman
, in its generally-agreed modern sense.
and an early analytic philosopher
, and had students of the calibre of Brand Blanshard
, Nelson Goodman
, and Roderick Chisholm
, his reputation declined after WWII, and the secondary literature on Lewis during the second half of the 20th century is less than imposing. Joel Isaac, in his contribution to the 2006 Transactions of the C. S. Peirce Society symposium referenced below, believes this neglect is justified. Lewis's reputation is benefiting from the growing interest in the historical aspects of pragmatism and of American philosophy generally.
Lewis's papers are kept at Stanford University
.
Ethics
Ethics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...
.
Early years
Lewis was born in Stoneham, MassachusettsStoneham, Massachusetts
Stoneham is a town in Middlesex County, Massachusetts. Its population was 21,437 at the 2010 census, down from 22,219 in 2000. The town is the birthplace of Olympic figure skating medalist Nancy Kerrigan and is the home of the Stone Zoo.- History :...
. His father was a skilled worker in a shoe factory, and Lewis grew up in relatively humble circumstances. He discovered philosophy at age 13, when reading about the Greek pre-Socratics, Anaxagoras
Anaxagoras
Anaxagoras was a Pre-Socratic Greek philosopher. Born in Clazomenae in Asia Minor, Anaxagoras was the first philosopher to bring philosophy from Ionia to Athens. He attempted to give a scientific account of eclipses, meteors, rainbows, and the sun, which he described as a fiery mass larger than...
and Heraclitus
Heraclitus
Heraclitus of Ephesus was a pre-Socratic Greek philosopher, a native of the Greek city Ephesus, Ionia, on the coast of Asia Minor. He was of distinguished parentage. Little is known about his early life and education, but he regarded himself as self-taught and a pioneer of wisdom...
in particular. The first work of philosophy Lewis recalled studying was a short history of Greek philosophy
Greek philosophy
Ancient Greek philosophy arose in the 6th century BCE and continued through the Hellenistic period, at which point Ancient Greece was incorporated in the Roman Empire...
by Marshall. Immanuel Kant
Immanuel Kant
Immanuel Kant was a German philosopher from Königsberg , researching, lecturing and writing on philosophy and anthropology at the end of the 18th Century Enlightenment....
proved a major lifelong influence on Lewis's thinking. In his article "Logic and Pragmatism," Lewis wrote: "Nothing comparable in importance happened [in my life] until I became acquainted with Kant... Kant compelled me. He had, so I felt, followed scepticism to its inevitable last stage, and laid the foundations where they could not be disturbed."
In 1905, Harvard College
Harvard College
Harvard College, in Cambridge, Massachusetts, is one of two schools within Harvard University granting undergraduate degrees...
awarded Lewis the A.B. after a mere three years of study, during which time he supported himself with part-time jobs. He then taught English for one year in a Quincy MA high school, then two years at the University of Colorado
University of Colorado at Boulder
The University of Colorado Boulder is a public research university located in Boulder, Colorado...
. In 1906, he married Mable Maxwell Graves. In 1908, Lewis returned to Harvard and began a Ph.D in philosophy, which he completed in a mere two years. He then taught philosophy at the University of California
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
, 1911–20, after which he returned again to Harvard, where he taught until his 1953 retirement, eventually filling the Edgar Pierce Chair of Philosophy. In 1929, he was elected to the American Academy of Arts and Sciences
American Academy of Arts and Sciences
The American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...
. In 1933, he presided over the American Philosophical Association
American Philosophical Association
The American Philosophical Association is the main professional organization for philosophers in the United States. Founded in 1900, its mission is to promote the exchange of ideas among philosophers, to encourage creative and scholarly activity in philosophy, to facilitate the professional work...
. For the academic year 1959-1960, he was a Fellow on the faculty in the Center for Advanced Studies at Wesleyan University
Wesleyan University
Wesleyan University is a private liberal arts college founded in 1831 and located in Middletown, Connecticut. According to the Carnegie Foundation for the Advancement of Teaching, Wesleyan is the only Baccalaureate College in the nation that emphasizes undergraduate instruction in the arts and...
.
Logic
Lewis studied logic under his eventual Ph.D. thesis supervisor, Josiah RoyceJosiah Royce
Josiah Royce was an American objective idealist philosopher.-Life:Royce, born in Grass Valley, California, grew up in pioneer California very soon after the California Gold Rush. He received the B.A...
, and is arguably the founder of modern philosophical logic
Philosophical logic
Philosophical logic is a term introduced by Bertrand Russell to represent his idea that the workings of natural language and thought can only be adequately represented by an artificial language; essentially it was his formalization program for the natural language...
. In 1912, two years after the publication of the first volume of Principia Mathematica
Principia Mathematica
The Principia Mathematica is a three-volume work on the foundations of mathematics, written by Alfred North Whitehead and Bertrand Russell and published in 1910, 1912, and 1913...
, Lewis began publishing articles taking exception to
Principia' s pervasive use of material implication, more specifically, to Bertrand Russell
Bertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, OM, FRS was a British philosopher, logician, mathematician, historian, and social critic. At various points in his life he considered himself a liberal, a socialist, and a pacifist, but he also admitted that he had never been any of these things...
's reading of a→b as "a implies b." Lewis restated this criticism in his reviews of both editions of PM. Lewis's reputation as a promising young logician was soon assured.
Material implication allows a true consequent to follow from a false antecedent. Lewis proposed to replace material implication with strict implication, such that a false antecedent can never strictly imply a true consequent. This strict implication was not primitive, but defined in terms of negation
Negation
In logic and mathematics, negation, also called logical complement, is an operation on propositions, truth values, or semantic values more generally. Intuitively, the negation of a proposition is true when that proposition is false, and vice versa. In classical logic negation is normally identified...
, conjunction
Logical conjunction
In logic and mathematics, a two-place logical operator and, also known as logical conjunction, results in true if both of its operands are true, otherwise the value of false....
, and a prefixed unary intensional
Intensional
Intensional* in philosophy of language: not extensional. See also intensional definition versus extensional definition.* in philosophy of mind: an intensional state is a state which has a propositional content....
modal operator
Modal operator
In modal logic, a modal operator is an operator which forms propositions from propositions. In general, a modal operator has the "formal" property of being non-truth-functional, and is "intuitively" characterised by expressing a modal attitude about the proposition to which the operator is applied...
,
. Let X be a formula with a classical bivalent truth value. Then X can be read as "X is possibly true" (or false, as the case may be). Lewis then defined "A strictly implies B" as "(AB)". Lewis's strict implication is now a historical curiosity, but the formal modal logicModal logic
Modal logic is a type of formal logic that extends classical propositional and predicate logic to include operators expressing modality. Modals — words that express modalities — qualify a statement. For example, the statement "John is happy" might be qualified by saying that John is...
in which he grounded that notion is the ancestor of all modern work on the subject. Lewis's
notation is still standard, but current practice usually takes its dual, ("necessity"), as primitive and as defined, in which case "A strictly implies B" is simply written as (A→B).His first logic text, A Survey of Symbolic Logic (1918), went out of print after selling only several hundred copies. At the time of its publication, it included the only discussion in English of the logical writings of Charles Peirce and only the second, after Russell's monograph of 1900, on Leibniz. While the modal logic
Modal logic
Modal logic is a type of formal logic that extends classical propositional and predicate logic to include operators expressing modality. Modals — words that express modalities — qualify a statement. For example, the statement "John is happy" might be qualified by saying that John is...
of A Survey was soon proved inconsistent, Lewis went on to devise the modal systems S1 to S5, and to set these out in Symbolic Logic (1932) as possible formal analyses of the alethic modalities. Lewis mildly preferred S2 over the others; the amended modal system of A Survey was S3. But it is S4 and S5
S5 (modal logic)
In logic and philosophy, S5 is one of five systems of modal logic proposed byClarence Irving Lewis and Cooper Harold Langford in their 1932 book Symbolic Logic.It is a normal modal logic, and one of the oldest systems of modal logic of any kind....
that have generated sustained interest, mathematical as well as philosophical, down to the present day. S4 and S5 are the beginning of what is now called normal modal logic
Normal modal logic
In logic, a normal modal logic is a set L of modal formulas such that L contains:* All propositional tautologies;* All instances of the Kripke schema: \Box\toand it is closed under:...
. On Lewis's strict implication and his modal systems S1-S5, see Hughes and Cresswell (1996: chpt. 11).
Pragmatist but no positivist
This section follows Dayton (2004) closely. Around 1930, American philosophy began to experience a turning point because of the arrival of logical empiricism, brought by continental philosophers fleeing the Third Reich. This new doctrine challenged American philosophers of a naturalistic or pragmatic bent, such as Lewis. In any event, logical empiricism, with its emphasis on scientific models of knowledge and on the logical analysis of meaning, soon emerged as a, and perhaps the, dominant tendency in American philosophy.While many saw Lewis as kin to the logical empiricists, he was never truly comfortable in such company because he declined to divorce experience from cognition. Positivism rejected value as lacking cognitive significance, also rejecting the analysis of experience in favor of physicalism. Both rejections struck him as regrettable. Indeed his growing awareness of the pragmatic tradition led him in the opposite direction. For Lewis, it is only within experience that anything can have significance for anything, and thus he came to see value as a way of representing the significance of knowledge for future conduct. These convictions led him to reflect on the differences between pragmatism
Pragmatism
Pragmatism is a philosophical tradition centered on the linking of practice and theory. It describes a process where theory is extracted from practice, and applied back to practice to form what is called intelligent practice...
and positivism
Positivism
Positivism is a a view of scientific methods and a philosophical approach, theory, or system based on the view that, in the social as well as natural sciences, sensory experiences and their logical and mathematical treatment are together the exclusive source of all worthwhile information....
, and on the cognitive structure of value experiences.
Lewis agreed that pragmatism
Pragmatism
Pragmatism is a philosophical tradition centered on the linking of practice and theory. It describes a process where theory is extracted from practice, and applied back to practice to form what is called intelligent practice...
committed one to the Peircean pragmatic test. But in a 1930 essay, "Pragmatism and Current Thought," he maintained that this commitment can be taken in either of two directions. One direction emphasises the subjectivity of experience. The other direction, and the one he took in 'his (1929), began with the Peirce's limitation of meaning to that which makes a verifiable difference in experience. Hence concepts are abstractions in which "the immediate is precisely that element which must be left out." But this claim must be properly understood. An operational account of concepts mainly eliminates the ineffable: "If your hours are felt as twice as long as mine, your pounds twice as heavy, that makes no difference, which can be tested, in our assignment of physical properties to things." Hence a concept is but a relational pattern. But it does not follow that one ought to discard the world as it is experienced:
"In one sense, that of connotation, a concept strictly comprises nothing but an abstract configuration of relations. In another sense, its denotation or empirical application, this meaning is vested in a process which characteristically begins with something given and ends with something done in the operation which translates a presented datum into an instrument of prediction and control."
Thus knowledge begins and ends in experience, keeping in mind that the beginning and ending experiences differ. Knowledge of something requires that the verifying experience be actually experienced. Thus for the pragmatist, verifiability as an operational definition (or test) of the empirical meaning of a statement requires that the speaker know how to apply the statement, and when not to apply it, and be able to trace the consequences of the statement in situations both real and hypothetical.
Lewis firmly objected to the positivist conception of value statements as devoid of cognitive content, as merely expressive. For a pragmatist, all judgements are implicitly value judgements. Lewis (1946) sets out both his conception of sense meaning, and his thesis that valuation is a form of empirical cognition.
In his essay "Logical Positivism and Pragmatism," Lewis revealed his disagreement with verificationism by comparing it unfavorably with his preferred pragmatic conception of empirical meaning. From the outset, he saw both pragmatism
Pragmatism
Pragmatism is a philosophical tradition centered on the linking of practice and theory. It describes a process where theory is extracted from practice, and applied back to practice to form what is called intelligent practice...
and logical positivism
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
as forms of empiricism
Empiricism
Empiricism is a theory of knowledge that asserts that knowledge comes only or primarily via sensory experience. One of several views of epistemology, the study of human knowledge, along with rationalism, idealism and historicism, empiricism emphasizes the role of experience and evidence,...
. At first glance, it would seem that the pragmatic conception of meaning, despite its different formulation and its focus on action, very much resembles the logical positivist verification requirement. Nevertheless, Lewis argued that there is a deep difference between the two: pragmatism ultimately grounds meaning on conceivable experience, while positivism reduces the relation between meaning and experience to a matter of logical form
Logical form
In logic, the logical form of a sentence or set of sentences is the form obtained by abstracting from the subject matter of its content terms or by regarding the content terms as mere placeholders or blanks on a form...
.
For Lewis, the positivist conception of meaning omits precisely what a pragmatist would count as empirical meaning. Specifying which observation sentences follow from a given sentence helps us determine the empirical meaning of the given sentence only if the observation sentences themselves have an already understood meaning in terms of the specific qualities of experience to which the predicates of the observation sentences refer. Thus Lewis saw the logical positivists as failing to distinguish between "linguistic" meaning, namely the logical relations among terms, and "empirical" meaning, namely the relation expressions have to experience. (In the well-known terminology of Carnap and Charles W. Morris
Charles W. Morris
Charles W. Morris was an American semiotician and philosopher.-Background:A son of Charles William and Laura Morris, Charles William Morris was born on May 23, 1901...
, empirical meaning falls under pragmatics
Pragmatics
Pragmatics is a subfield of linguistics which studies the ways in which context contributes to meaning. Pragmatics encompasses speech act theory, conversational implicature, talk in interaction and other approaches to language behavior in philosophy, sociology, and linguistics. It studies how the...
, linguistic meaning
Linguistic meaning
The nature of meaning, its definition, elements, and types, was discussed by philosophers Aristotle, Augustine, and Aquinas. According to them 'meaning is a relationship between two sorts of things: signs and the kinds of things they mean '. One term in the relationship of meaning necessarily...
under semantics
Semantics
Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....
.) For Lewis, the logical positivist shuts his eyes to precisely that which properly confirms a sentence, namely the content of experience.
Epistemology
Lewis (1929), Mind and the World Order, is now seen as one of the most important 20th century works in epistemology. Lewis is now included among the American pragmatistPragmatist
Pragmatist may refer to:*A person who subscribes to pragmatism, a field of philosophy*A person who subscribes to pragmaticism, Charles Sanders Peirce's post-1905 branch of philosophy...
s, a belated assessment that is the major theme of Murphey (2005).
Ethics and esthetics
Lewis's late writings on ethics include the monographs Lewis (1955, 1957) and the posthumous collection Lewis (1969). From 1950 until his death, he wrote many drafts of chapters of a proposed treatise on ethicsEthics
Ethics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...
, which he did not live to complete. These drafts are included in the Lewis papers held at Stanford University.
Lewis (1947) contains two chapters on esthetics and the philosophy of art. He was the first to employ the term "qualia
Qualia
Qualia , singular "quale" , from a Latin word meaning for "what sort" or "what kind," is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'. Examples of qualia are the pain of a headache, the taste of wine, the experience of taking a recreational drug, or the...
", popularized by his student Nelson Goodman
Nelson Goodman
Henry Nelson Goodman was an American philosopher, known for his work on counterfactuals, mereology, the problem of induction, irrealism and aesthetics.-Career:...
, in its generally-agreed modern sense.
Legacy
Even though Lewis set out his ideas at length, can be seen as both a late pragmatistPragmatism
Pragmatism is a philosophical tradition centered on the linking of practice and theory. It describes a process where theory is extracted from practice, and applied back to practice to form what is called intelligent practice...
and an early analytic philosopher
Analytic philosophy
Analytic philosophy is a generic term for a style of philosophy that came to dominate English-speaking countries in the 20th century...
, and had students of the calibre of Brand Blanshard
Brand Blanshard
Percy Brand Blanshard was an American philosopher known primarily for his defense of reason. A powerful polemicist, by all accounts he comported himself with courtesy and grace in philosophical controversies and exemplified the "rational temper" he advocated.-Life:Brand Blanshard was born August...
, Nelson Goodman
Nelson Goodman
Henry Nelson Goodman was an American philosopher, known for his work on counterfactuals, mereology, the problem of induction, irrealism and aesthetics.-Career:...
, and Roderick Chisholm
Roderick Chisholm
Roderick M. Chisholm was an American philosopher known for his work on epistemology, metaphysics, free will, and the philosophy of perception. He received his Ph.D. at Harvard University under Clarence Irving Lewis and Donald C. Williams, and taught at Brown University...
, his reputation declined after WWII, and the secondary literature on Lewis during the second half of the 20th century is less than imposing. Joel Isaac, in his contribution to the 2006 Transactions of the C. S. Peirce Society symposium referenced below, believes this neglect is justified. Lewis's reputation is benefiting from the growing interest in the historical aspects of pragmatism and of American philosophy generally.
Lewis's papers are kept at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
.
Personal life
Lewis's life was not free of trials. His daughter died in 1930 and he suffered a heart attack in 1932. Nevertheless, the publications of Lewis (1929) and Lewis and Langford (1932) attest to this having been a highly productive period of his life.See also
- American philosophyAmerican philosophyAmerican philosophy is the philosophical activity or output of Americans, both within the United States and abroad. The Internet Encyclopedia of Philosophy notes that while American philosophy lacks a "core of defining features, American Philosophy can nevertheless be seen as both reflecting and...
- PragmatismPragmatismPragmatism is a philosophical tradition centered on the linking of practice and theory. It describes a process where theory is extracted from practice, and applied back to practice to form what is called intelligent practice...
- Modal logicModal logicModal logic is a type of formal logic that extends classical propositional and predicate logic to include operators expressing modality. Modals — words that express modalities — qualify a statement. For example, the statement "John is happy" might be qualified by saying that John is...
- Interior algebraInterior algebraIn abstract algebra, an interior algebra is a certain type of algebraic structure that encodes the idea of the topological interior of a set. Interior algebras are to topology and the modal logic S4 what Boolean algebras are to set theory and ordinary propositional logic...
- List of American philosophers
Further reading
- Dayton, Eric, 2006, "Clarence Irving Lewis" in the Internet Encyclopedia of PhilosophyInternet Encyclopedia of PhilosophyThe Internet Encyclopedia of Philosophy is a free online encyclopedia on philosophical topics and philosophers founded by James Fieser in 1995. The current general editors are James Fieser and Bradley Dowden...
. - Hunter, Bruce, 2007 "Clarence Irving Lewis" in The Stanford Encyclopedia of PhilosophyStanford Encyclopedia of PhilosophyThe Stanford Encyclopedia of Philosophy is a freely-accessible online encyclopedia of philosophy maintained by Stanford University. Each entry is written and maintained by an expert in the field, including professors from over 65 academic institutions worldwide...
. - Ivor Grattan-GuinnessIvor Grattan-GuinnessIvor Grattan-Guinness, born 23 June 1941, in Bakewell, in England, is a historian of mathematics and logic.He gained his Bachelor degree as a Mathematics Scholar at Wadham College, Oxford, got an M.Sc in Mathematical Logic and the Philosophy of Science at the London School of Economics in 1966...
, 2000. The Search for Mathematical Roots 1870-1940. Princeton Univ. Press. - Hughes, G. E., and M.J. Cresswell (1996) A New Introduction to Modal Logic. Routledge. ISBN 0-415-12599-5
- Murphey, Murray G., 2005. C. I. Lewis: The Last Great Pragmatist. SUNY Press.
- 2006, "Symposium on M. G. Murphey's C. I. Lewis: The Last Great Pragmatist," Transactions of the C. S. Peirce Society 42: 1-77. With contributions by S. F. Barker, John Corcoran, Eric Dayton, John Greco, Joel Isaac, Murphey, Richard S. Robin, and Naomi Zack.
- Schilpp, P. A., ed., 1968. The Philosophy of C. I. Lewis (The Library of Living PhilosophersLibrary of Living PhilosophersThe Library of Living Philosophers is a series of books conceived of and started by Paul Arthur Schilpp in 1939; Schilpp remained editor until 1981. The series was edited by Lewis Edwin Hahn from 1981 until 2001, and is currently edited by Randall Auxier...
, vol. 13). Open Court. Includes an autobiographical essay.