Anarchist theory assumes that non-hierarchically organised societies both possible and desirable. To show the former requires empirical evidence and a discussion of the theoretical preconditions of cooperation. To show the latter, it is necessary to show that the faults found with the state can be remedied within non-hierarchically ordered societies. One obvious condition for a successful anarchist theory is that the solutions to these separate tasks are mutually consistent. It is the aim of this thesis to show that the theories (...) of Robert Paul Wolff and Robert Nozick are found wanting in this respect. Both their theories of agency rule out the possibility of non-coercive and stable cooperation, which is a necessary precondition for an anarchist society. I conclude with a brief discussion of Michael Taylor's communitarian proposal and defend it against the liberal. (shrink)