"Robert Nozick [1938–2002] almost single-handedly made libertarian political philosophy respectable within mainstream academia with the 1974 publication of his now classic Anarchy, State and Utopia, which garnered a National Book Award the following year. Anarchy, State and Utopia argues, among other things, that a distribution of goods is just so long as the distribution was brought about by free exchanges by consenting adults, even if large inequalities emerge from the process. Nozick here challenges John Rawls's arguments in A Theory of Justice that conclude that inequalities must at least make the worst off better off in order to be morally justified.

Nozick, among the leading figures in contemporary Anglo-American philosophy, made significant contributions to almost every major area of philosophy. In Philosophical Explanations (1981), Nozick provides novel accounts of knowledge, free-will, and the nature of value. The Examined Life (1989), pitched to a broader public, explores love, death, faith and the meaning of life. The Nature of Rationality (1993) presents a theory of practical reason that attempts to embellish notoriously spartan classical decision theory. Socratic Puzzles (1997) is a collection of papers that range from Ayn Rand and Austrian economics to animal rights, while his latest production, Invariances (2001) applies insights from physics and biology to question of objectivity in such areas as the nature of necessity and moral value.

Nozick was notable for his curious, exploratory style and methodological ecumenism. Often content to raise tantalizing philosophical possibilities and then leave judgment to the reader, Nozick was also notable for inventively drawing from literature outside of philosophy (e.g., economics, physics, evolutionary biology) to infuse his work with freshness and relevance...." (from libertyguide.com)

[Robert] Nozick was named Joseph Pellegrino University Professor at Harvard University in 1998. "[He] came to Harvard from an assistant professorship at Princeton University in 1965. He served as an assistant professor [at Harvard] for two years and went to Rockefeller University in 1967 as an associate professor. He returned to Harvard at age 30 as a full professor of philosophy in 1969. He served as chair of the Philosophy Department from 1981 to 1984.

Though already well-known at Harvard and in philosophical circles, Nozick burst onto the public consciousness in 1974 with his book Anarchy, State, and Utopia.

He followed that book with four other works: Philosophical Explanations, a book on the nature of knowledge, the self, free will, and ethics, which won the Ralph Waldo Emerson Award of Phi Beta Kappa; The Examined Life, a book of reflections on themes such as love, happiness, and creativity, as well as evil and the Holocaust; The Nature of Rationality, which studies and develops formal models of rational action and rational belief; and, most recently, Socratic Puzzles in 1997, a collection of his articles, reviews, and works of fiction....

...Nozick's first book, Anarchy, State, and Utopia, won a National Book Award and propelled him into the public eye. The book, championing individual liberties, argued that the rights of the individual are so sweeping and primary that nothing more than a minimal state—sufficient to protect against violence, theft, and to ensure the enforcement of contracts—is warranted. The book also argues that the justice of a distribution depends upon the process by which it arises rather than upon the pattern that it exhibits.

Anarchy, which was listed by The Times Literary Supplement as one of "The Hundred Most Influential Books Since the War," is still in print and has been translated into 11 languages...." (from online version of the Harvard University Gazette, October 1, 1998)

"Robert Nozick was, with John Rawls, one of the two most important and influential political philosophers in the Anglo-American analytic tradition. Where Rawls's work systematized the egalitarian liberalism of the political Left, Nozick did the same for the free-market libertarianism of the Right. A thinker with wide-ranging interests, he also made a number of significant contributions to areas of philosophy outside political theory, most notably in epistemology and the metaphysics of personal identity.

Robert Nozick, who until his death in January 2002 taught at Harvard University, was a thinker of the prodigious sort who gains a reputation for brilliance within his chosen field while still in graduate school, in his case at the Princeton of the early 1960's, where he wrote his dissertation on decision theory under the supervision of Carl Hempel. He was also, like so many young intellectuals of that period, drawn initially to the politics of the New Left and to the socialism that was its philosophical inspiration. But encountering the works of such defenders of capitalism as F.A. Hayek, Ludwig von Mises, Murray Rothbard, and Ayn Rand eventually led him to renounce those views, and to shift his philosophical focus away from the technical issues then dominating analytic philosophy and toward political theory. The result was his first and most famous book, Anarchy, State, and Utopia (1974), an ingenious defense of libertarianism that immediately took on canonical status as the major right-wing philosophical counterpoint to his Harvard colleague John Rawls's influential defense of social-democratic liberalism, A Theory of Justice (1971).

Like Rawls's book, Nozick's generated lively debate and an enormous secondary literature. But where Rawls made the development of his theory of justice and its defense against critics his life's work, Nozick took little interest either in responding to critics of Anarchy, State, and Utopia in particular or in continuing to do systematic work in political philosophy in general. Instead, he moved on to produce groundbreaking work in several other areas of philosophical inquiry, particularly in epistemology and metaphysics. His development of an externalist theory of knowledge and his "closest continuer" account of personal identity have been particularly influential. It remains to be seen what impact on philosophy will be made by the general theory of objective truth developed in his last book, Invariances (2001), published shortly before his untimely death from stomach cancer. In any case, it seems clear, judging from the disproportionate amount of attention that it has received relative to the rest of his writings, that it is his early work in political theory that will stand as his most significant and lasting contribution...." (from The Internet Encyclopedia of Philosophy)

"...His first book, "Anarchy, State, and Utopia" (1974), transformed him from a young philosophy professor known only within his profession to the reluctant theoretician of a national political movement.

He wrote the book as a critique of "Theory of Justice" (1971), by his Harvard colleague John Rawls, the James Bryant Conant University Professor Emeritus. Rawls' book provided a philosophical underpinning for the bureaucratic welfare state, a methodically reasoned argument for why it was right for the state to redistribute wealth in order to help the poor and disadvantaged....

...A former member of the radical left who was converted to a libertarian perspective as a graduate student, largely through his reading of conservative economists Friedrich Hayek and Milton Friedman, Nozick was never comfortable with his putative status as an ideologue of the right.

In a 1978 article in The New York Times Magazine he said that "right-wing people like the pro-free-market argument, but don't like the arguments for individual liberty in cases like gay rights– although I view them as an interconnecting whole...."

Whether they agreed or disagreed with the political implication of the book, critics were nearly unanimous in their appreciation for Nozick's lively, accessible writing style. In a discipline known for arduous writing, Nozick's approach was hailed as a breath of fresh air...." (from online article about Robert Nozick's death in the Harvard University Gazette, January 17, 2002 edition)