was an American philosopher. He held the Joseph Pellegrino University Professorship at Harvard University,[3] and was president of the American Philosophical Association. He is best known for his book Anarchy, State, and Utopia (1974), a libertarian answer to John Rawls' A Theory of Justice (1971), in which Nozick proposes his minimal state as the only justifiable form of government. His later work Philosophical Explanations (1981) advanced notable epistemological claims, namely his counterfactual theory of knowledge.