Abstract: Kukathas, in “Two Constructions of Libertarianism,” concludes that “the choice confronting libertarians is an invidious one. … The Federation of Liberty can, in principle, turn out to contain no communities of that federation which actually value or respect liberty; and even slavery might have a lawful place within it. The Union of Liberty, on the other hand, can, in principle turn out to be society ruled by a strong authority with little respect for dissenting moral traditions, including some self-styled libertarian moral traditions.” However, no such choice needs to be made. The one libertarian principle calls upon us to permit all voluntary association. It allows intervention to correct involuntary association, except in the case of relations of parents and children, the latter being not yet exactly persons. But the criterion of voluntariness is difficult, since people frequently submit themselves to authorities, even to ones who are authorized by those persons to use force against them. And it does not require us to intervene to correct injustices generally.
It is not clear what a “libertarian community” would be, beyond one in which relations among individuals and groups are fundamentally voluntary. But there is no difference between (1) allowing and (2) forbidding the disallowing of various practices, and that is the distinction which in essence the Federation versus the Union is defined in terms of. And the question whether to attempt to realize the libertarian principle better by erecting a single government with the kind of authority governments by definition have, versus making do with a fully anarchic society, is, I think, not settled to this day. Fortunately, as I have argued, the choice is not required by the alternatives Professor Kukathas’s interesting essay poses for us. In short: the libertarian principle remains univocal: no aggression against those not themselves guilty of any aggression. And therefore, no aggression against those with whom we disagree, including about the legitimacy of the libertarian principle. But, certainly, we may use force against those who compel others to go along. The touchstone remains the liberty of the individual.