This is our final post regarding the new Routledge Handbook of Libertarianism, a remarkable collection of erudite essays which was published earlier this year. (During the previous three weeks, we have reviewed 11 select essays from the Libertarian Handbook.) In this concluding post, we shall go back to first principles to point out two foundational problems with libertarian theory, a predicament that is not solved in the Libertarian Handbook. Simply put, the problem is this: What is the moral basis of libertarianism? Do we have a natural, God-given, or pre-political right to liberty, or is freedom simply a pragmatic or instrumental means to an end? (Or in the words of John Thrasher, who contributed an excellent essay to the handbook: should we “base libertarian conclusions on some deontological basis (e.g., natural rights) or [should we] adopt a consequentialist justification”?
Furthermore, whether we prefer a deontological or consequentialist approach to liberty, how are we able to justify any reasonable limits on our liberties? Simply saying that “my freedom ends where your freedom begins” (or “my right to swing my fist ends where your nose begins”) is by itself totally unhelpful without a general theory of consent or a general theory of harm. After all, what if two men are participating in a consensual boxing match, or what if I have to defend myself or my family from an unprovoked aggressor? In these cases, consent or the threat of imminent harm, as the case may be, can then serve as a powerful moral justification (or moral trump, pun intended) in favor of the use of force. (Or consider the meme pictured below. Why should freedom end at one’s nose, so to speak? Why not take into account the slippery slope of so-called psychic harms?) Is there any way out of this normative swamp? Instead of committing ourselves to either a rights-based justification of liberty or an instrumentalist one, we would create a general rebuttable presumption in favor of liberty. That is, in the absence of a good justification for restricting freedom (and regardless of the moral source of such justification), people should be free to do whatever they want. This libertarian formulation is by no means perfect. What is? But at least it avoids moral slippery slopes by shifting the burden of proof onto the enemies of liberty.