Clarence Irving Lewis (April 12, 1883 Stoneham, Massachusetts - February 3, 1964 Cambridge, Massachusetts) was an American academic philosopher. Educated at Harvard University, he taught there 1920-1953, after a stint at the University of California, 1912-20. Willard Quine was the next person to fill his Chair in Harvard's Philosophy department. April 12 is the 102nd day of the year in the Gregorian calendar (103rd in leap years). ... 1883 was a common year starting on Monday (see link for calendar). ... Welcome to Stoneham Massachusetts Stoneham is a town located in Middlesex County, Massachusetts. ... February 3 is the 34th day of the year in the Gregorian Calendar. ... For the Nintendo 64 emulator, see 1964 (Emulator). ... Cambridge City Hall Cambridge is a city in the Greater Boston area of Massachusetts, United States. ... A philosopher is a person devoted to studying and producing results in philosophy. ... Harvard University is a private university in Cambridge, Massachusetts, USA, and a member of the Ivy League. ... The University of California (UC) is a public university system within the State of California. ... W. V. Quine Willard Van Orman Quine (June 25, 1908 - December 25, 2000) was one of the most influential American philosophers and logicians of the 20th century. ...

Lewis is included among the American pragmatists. He wrote at length about epistemology and ethics, and supported Bayesian probability. He was also the first to employ the term "qualia", popularized by his student Nelson Goodman, in its generally-agreed modern sense. Pragmatism is a school of philosophy which originated in the United States in the late 1800s. ... Epistemology, from the Greek words episteme (knowledge) and logos (word/speech) is the branch of philosophy that deals with the nature, origin and scope of knowledge. ... Ethics (from Greek ethikos) is the branch of axiology – one of the four major branches of philosophy, alongside metaphysics, epistemology, and logic – which attempts to understand the nature of morality; to define that which is right from that which is wrong. ... Bayesianism is the philosophical tenet that the mathematical theory of probability applies to the degree of plausibility of a statement. ... This article is about the philosophical concept. ... This article needs to be wikified. ...

Lewis was a major logician, learning the subject from Josiah Royce who also supervised his Ph.D. thesis. Lewis took exception to Bertrand Russell's notion of material implication that pervades Principia Mathematica. Lewis's response was to devise a system of modal logic that is the ancestor of all modern work on the subject. Lewis and Langford (1932), the culmination of Lewis's work on logic, sets out the modal logics S1 through S5 as the first formal analyses of the alethic modalities. Josiah Royce (November 20, 1855 – September 14, 1916) was an American objective idealist philosopher. ... Wikisource has original works written by or about: Bertrand Russell Writings available online A Free Mans Worship (1903) Am I an Atheist or an Agnostic? Icarus: The Future of Science Has Religion Made Useful Contributions to Civilization? Ideas that Have Harmed Mankind In Praise of Idleness (1932) Nobel Lecture... In logical calculus of mathematics, the logical conditional (also known as the material implication, sometimes material conditional) is a binary logical operator connecting two statements, if p then q where p is a hypothesis (or antecedent) and q is a conclusion (or consequent). ... The Principia Mathematica is a three-volume work on the foundations of mathematics, written by Alfred North Whitehead and Bertrand Russell and published in 1910-1913. ... A modal logic, or (less commonly) intensional logic, is a logic that deals with sentences that are qualified by modalities such as can, could, might, may, must, possibly, necessarily, eventually, etc. ... ...

Selected works

Online bibliography.

• 1918. A Survey of Symbolic Logic. Partly republished by Dover in 1960.
• 1932. Symbolic Logic (with Cooper H Langford). Dover reprint, 1959.
• 1947. An Analysis of Knowledge and Valuation.
• 1955. The Ground and Nature of Right.
• 1956 (1929). Mind and World Order: Outline of a Theory of Knowledge.
• 1957. Our Social Inheritance.
• 1969 (John Lange, ed.). Values and Imperatives: Studies in Ethics. Stanford Uni. Press.
• 1970 (Goheen, J. D., and Mothershead, J. L. Jr., eds. ). Collected Papers. Stanford Uni. Press.

Secondary literature:

• Schilpp, P. A., ed., 1968. The Philosophy of C. I. Lewis (The Library of Living Philosophers, vol. 13). Open Court. Contains an autobiographical essay and extensive discussion of his work.
• Ivor Grattan-Guinness, 2000. The Search for Mathematical Roots 1870-1940. Princeton University Press.

Ivor Grattan-Guiness is a prolific contemporary historian of mathematics and logic. ...

Resources

• Article on Clarence Irving Lewis at the Internet Encyclopedia of Philosophy.