Abstract
Libertarianism is the view that we all have one single, general, fundamental right – the right to liberty. Rights imply duties, of course: for a certain agent, A, to have a right is for A to have a status such that other people are required to behave in certain ways towards A in the respects implied by the specific content of that right. For A to have the right to do x is for A to be such that some other person or persons is or are obligated to act in certain ways in relation to A's x‐ing. So one can, substantively speaking, equivalently express the libertarian view as a general prohibition on aggression. An important further matter: What about the enforcement of this requirement? The libertarian principle prohibits aggression – not, flatly, all use or threat of force; it merely restricts it to defensive purposes.