Ludwig Josef Johann Wittgenstein (April 26, 1889 in Vienna, Austria - April 29, 1951 in Cambridge, England) was an Austrian philosopher who contributed several ground-breaking ideas to philosophy, primarily in the foundations of logic, the philosophy of mathematics, the philosophy of language, and the philosophy of mind. His influence has been wide-ranging, placing him among the most significant philosophers of the 20th century.

Peter Guy Winch (1926-1997) was a British philosopher known for his contributions to the philosophy of the social sciences, Wittgenstein scholarship, ethics, and the philosophy of religion. Winch is perhaps most famous for his early book, "The Idea of a Social Science and its Relation to Philosophy" (1958), an attack on positivism in the social sciences, drawing on the work of R. G. Collingwood and Ludwig Wittgenstein's later philosophy.

Rush Rhees (19 March1905-22 May1989) was a philosopher at Swansea University from 1940 to 1966 Rhees is principally known as a student, friend, and literary executor of the philosopher Ludwig Wittgenstein. With G. E. M. Anscombe, he edited Wittgenstein's posthumous "Philosophical Investigations" (1953), a highly influential work. He was also responsible for bringing out other unpublished writings by Wittgenstein, including "Remarks on the Foundations of Mathematics", …

Philippa Ruth Foot (1920-), (born Bosanquet) is a British philosopher, most notable for her works in ethics. She is one of the founders of contemporary virtue ethics. Her work, especially her most recent work, may be seen as an attempt to modernize Aristotelian ethical theory, to show that it was adaptable to current issues, and thus that it could compete with such popular theories as modern deontological and utilitarian ethics.

Gilbert Ryle (Brighton, 19 August 1900-Oxford, 6 October 1976), was a philosopher, and a representative of the generation of British ordinary language philosophers influenced by Wittgenstein's insights into language, and is principally known for his critique of Cartesian dualism, for which he coined the phrase "the ghost in the machine".

Professor Saul Kripke (Philosophy), who had been a visiting professor at The Graduate Center since Spring 2002, now joins the faculty as a Professor of Philosophy. He is known as a brilliant logician and one of the most important philosophers of the 20th century. While a high school student in Nebraska, he wrote a series of papers that transformed modal logic and remain canonical works in the field.

Stanley Louis Cavell (born September 1, 1926) is an American philosopher. He is the Walter M. Cabot Professor Emeritus of Aesthetics and the General Theory of Value at Harvard University.

G. E. M. Anscombe (18 March, 1919 - 5 January, 2001) (born Gertrude Elizabeth Margaret Anscombe, also known as Elizabeth Anscombe) was a British analytic philosopher. A student of Ludwig Wittgenstein, she became an authority on his work, and edited and translated many books drawn from his writings, above all his "Philosophical Investigations". She wrote on the philosophy of mind, philosophy of action, philosophical logic, …

Norman Malcolm (1911 - 1990) was an American philosopher. He was born in Selden, Kansas. After earning a Harvard doctorate, he joined the Princeton faculty in 1940. During his first term at Cambridge in 1938, he met Ludwig Wittgenstein and attended Wittgenstein's lectures on the philosophical foundations of mathematics throughout 1939. Malcolm remained one of Wittgenstein's closest friends, and his memoir of his time with Wittgenstein, published in 1958, …

Cora Diamond is a US-born philosopher. She has worked on problems in analytic philosophy, the interpretation of Ludwig Wittgenstein, and moral philosophy. A moral vegetarian, she has also examined the rhetorical and philosophical nature of contemporary attitudes towards animal rights. An article of hers, "What Nonsense Might Be", criticizes the way that the logical positivists think about nonsense on Fregean grounds.

Peter Michael Stephan Hacker (born 15 July1939 in London) is a British philosopher. His principal expertise is in the philosophy of mind and philosophy of language. He is well known for his detailed exegesis of the work of Ludwig Wittgenstein, and his outspoken criticism of neuroscience-based philosophy.

James Ferguson Conant (b. June 10, 1958) is an American philosopher who has written extensively on topics in philosophy of language, ethics, and metaphilosophy. He is perhaps best known for his writings on Wittgenstein, and his association with the New Wittgenstein school of Wittgenstein interpretation. He has also written on Stanley Cavell, Friedrich Nietzsche, and Soren Kierkegaard, edited two volumes of Hilary Putnam's papers, …

Sandra Laugier is a French philosopher, working on the philosophy of language, philosophy of action, ethics and philosophy of science. She is currently a professor at the University of Picardie Jules Verne in Amiens, France. She also introduced several aspects of American philosophy to French readers (Emerson, Thoreau, but above others Stanley Cavell).

Peter Thomas Geach (b. 29 March 1916) is a British philosopher. His areas of interest are the history of philosophy, philosophical logic, the theory of identity, and the philosophy of religion. His early work includes the classic texts "Mental Acts", and "Reference and Generality", which defends an essentially modern conception of reference against medieval theories of supposition. His Catholic perspective is integral to his philosophy.

Saul Kripke is known as a brilliant logician and one of the most important philosophers of the twentieth century. While a high-school student in Nebraska, he wrote a series of papers that transformed modal logic and remain canonical works in the field. He became a junior fellow at Harvard in his sophomore year and gave lectures to graduate students at the Massachusetts Institute of Technology.