Robert Nozick was an American philosopher at Harvard whose Anarchy, State, and Utopia (1974) was written as a direct reply to John Rawls and became the standard statement of libertarian political philosophy.

The entitlement theory

Nozick argues that justice in holdings is historical rather than patterned. A distribution is just if it arose from just acquisition and just transfer, whatever shape it happens to take. There is no further test to apply to the resulting pattern.

The consequence is sharp. Any principle that specifies what the distribution should look like — equality, or Rawls's requirement that inequalities benefit the worst off — must be maintained by continuous interference with voluntary exchanges people are entitled to make.

The Wilt Chamberlain argument

His illustration: begin from whatever distribution you consider just. Suppose a great many people each freely pay a small sum to watch one basketball player perform. The pattern is now disturbed and one person is much richer, by a sequence of transfers nobody objects to individually. Either the new distribution is just, or some voluntary transfer between consenting adults was not permissible.

The minimal state

He argues that a state limited to protection against force, theft and fraud, and to enforcing contracts, can arise without violating anyone's rights — and that anything more extensive cannot be justified. Taxation for redistribution is, on his account, on a par with forced labor.

Later

Nozick did not defend the position for the rest of his career, and wrote that the libertarian view now seemed to him seriously inadequate. He also worked on epistemology, decision theory and the meaning of life, and disliked being treated as the author of one book.