Epistemology ( (listen); from Greek, Modern ἐπιστήμη, epistēmē, meaning 'knowledge', and -logy) is the branch of philosophy concerned with the theory of knowledge.
Epistemology is the study of the nature of knowledge, justification, and the rationality of belief. Much debate in epistemology centers on four areas: (1) the philosophical analysis of the nature of knowledge and how it relates to such concepts as truth, belief, and justification, (2) various problems of skepticism, (3) the sources and scope of knowledge and justified belief, and (4) the criteria for knowledge and justification. Epistemology addresses such questions as: "What makes justified beliefs justified?", "What does it mean to say that we know something?", and fundamentally "How do we know that we know?"
The Gettier problem is considered a fundamental problem in modern epistemology or first-order logic, issuing from counter-examples to the definition of knowledge as justified true belief, and dealing extensively with the concept of justified true belief (JTB), and the scope of the concept of JTB, as well as those attacks upon JTB which Gettier exemplars introduce. The problem owes its name to a three-page paper published in 1963, by Edmund Gettier, called "Is Justified True Belief Knowledge?", in which Gettier argues that this is not necessarily the case. Many or most analytic philosophers would wish to be able to hold to what is known as the JTB account of knowledge: the claim that knowledge can be conceptually analyzed as justified true belief — which is to say that the meaning of sentences such as "Smith knows that it rained today" can be given with the following set of necessary and jointly sufficient conditions:
A subject S knows that a proposition P is true if, and only if:
- P is true
- S believes that P is true, and
- S is justified in believing that P
Robert Nozick (November 16, 1938 – January 23, 2002) was an American philosopher and Pellegrino University Professor at Harvard University. Nozick, schooled at Columbia, Oxford and Princeton, was a prominent American political philosopher in the 1970s and 1980s. He did additional but less influential work in such subjects as decision theory and epistemology. His Anarchy, State, and Utopia (1974) was a libertarian answer to John Rawls' A Theory of Justice, published in 1971. He was born in Brooklyn, the son of a Jewish entrepreneur from Russia. He was married to the American poet Gjertrud Schnackenberg. Nozick died in 2002 after a prolonged struggle with cancer. His remains are interred at Mount Auburn Cemetery in Cambridge, Massachusetts.