Most students of philosophy know that _Anarchy, State and Utopia_ has been a continual source of embarrassment for Robert Nozick since its publication. In multiple subsequent works, Nozick recants, repudiates, or otherwise distances himself from this strenuously argued turkey that Randian libertarians nevertheless cling to with appalling vigor. (Just look at the rest of the reviews.)
In particular, Nozick's flaws include the following:
1) A poor examination of protective agencies -- a concept borrowed from anarcho-capitalists of the 60s anyhow, Nozick never provides the critical connection between these agencies and a sorting criterion of fairness.
2) The basics of the right to private property are asserted, rather than explained. Nozick actually *deconstructs* the Lockean theory of acquisition with devastating effectiveness, but then waves away the problems he's created with little more than, "Some may think this important, but I think it won't be in any miminal state." Ooh, convincing.
3) Nozick doesn't seem to understand the concept of lexical priority. Nozick's concept of basic individual rights never outlines any hierarchy for when these rights come into conflict, despite the confusing chapter on the authorization of boundary-crossings. Ultimately, we are led to assume that the right to property (and specifically, the right to contract) is the foundation for all other rights -- but two enormous holes present themselves: (a) why? and (b) how is it that we can contract away our lesser rights, but not contract away the right to contract itself?
Ultimately, _Anarchy, State, and Utopia_ is revealed as a slipshod, poorly constructed, weakly argued propagandist piece. It is painful to read, excruciating to follow, and would be amusing, were it not so frightening. Pass.