One of the major fault lines in libertarian theory runs between those who regard the state as inherently evil (the “anarcho-capitalists”) and those who contend that the minimal state, i.e. one limited essentially to the provision of national defense and domestic law enforcement, is morally legitimate. The anarcho-capitalist indictment of the state is quite simple and straight-forward: any coercion employed against innocent persons (those not themselves engaged in aggression against others) is wrong (the “non-aggression principle”). Since the minimal state, among other things, collects taxes on a non-consensual basis to fund its activities, it is morally objectionable.
The anarchist argument will not trouble those who start with different moral presuppositions. Thus, utilitarians would simply reply that the practical advantages of the state in terms of promoting the general welfare justify coercion, at least for its “core” functions. However, since Nozick himself embraces the non-aggression principle, this avenue is unavailable to him. Rather, he tries to show in ASU that because the market for protective services is a sort of natural monopoly, the minimal state could evolve (and presumably operate) in a manner that does not violate the rights of any party, thereby blunting the anarchist claim that states are intrinsically evil. Nozick’s effort is almost universally (and correctly I believe) regarded as a failure, so I will not discuss it further here.
Thus, we are faced with the question of whether the minimal state can be justified from Nozick’s natural rights perspective. I believe that the most promising approach to this challenge is to argue that coercion employed to fund the activities of the minimal state stands on a different moral footing than it otherwise would. This process starts with the observation that for Nozick our moral agency is the source of special normative status (see the discussion under the link “Natural Rights Libertarianism”). Accordingly, it may be possible to distinguish, from an ethical perspective, state functions that are essential for the preservation of moral agency and those that are not. Arguably, protection from foreign attack or criminal violence is a basic precondition to the exercise of our moral discretion, and thus justified by the very value that gives rise to side constraints against aggression.
So, we can pose this question by means of the imaginary case of a peace-loving island community threatened with imminent invasion by a bloodthirsty horde of barbarians who will murder many of them and enslave the rest. The islanders can successfully repel this invasion if everyone does his or her fair share through the contribution of goods and/or services. Accordingly, the islanders form a government whose sole function is to manage the defense of the island. To do so it requests donations with which to pay its new volunteer army and to make weapons.
Sadly, while most members of the community willingly give their fair share, there are hold-outs who either sincerely object to the use of force even in self-defense or who, on a calculating basis, seek to free ride on the contributions of others. Without the application of coercion against these holdouts, the defense effort will probably fail. In such circumstances is coercion by the island’s government justified? I believe it is, even against the sincere pacifists.
The basis for this conclusion rests on something like the “principle of fairness” first articulated by H.L.A. Hart. Basically, it is simply unfair for some members of a community to reap the benefits of the efforts of others while refusing to contribute themselves, i.e. by free riding.
Although more controversial, I believe this principle even applies to the pacifists on the island who do not regard expenditures on self-defense as a benefit to them. They must enjoy life or they would have ended it; and they must enjoy their property, or they would have given it away. Thus, they benefit from the defense by others of their lives and property. Pacifists may be sincere free riders, but free riders nonetheless. Therefore, the community, acting through the state, is entitled to force them to live up to their obligations.
Interestingly, Nozick considers and then rejects the principle of fairness by proposing a counterexample. However, his case involves a trivial benefit (entertainment) provided by members of a neighborhood group, and he correctly concludes that the holdout in his case is under no obligation to contribute to the supply of this good (see ASU, 90-5). He does not analyze examples of the sort constructed above, and thus fails to refute the principle of fairness, at least when it is restricted to goods essential for the exercise of moral agency.
Accordingly, I believe the principle of fairness remains viable as a justification for state coercion in the supply of national defense, at least when the state in question is a reasonably just one faced by a realistic threat of aggression.