Recently, I concluded a critical essay on the Non-Aggression Principle (NAP) by making the following claim:

there comes a point where adding another layer of epicycles to one’s theory seems no longer to be the best way to proceed. There comes a point where what you need is not another refinement to the definition of “aggression” but a radical paradigm shift in which we put aside the idea that non-aggression is the sole, immovable center of the moral universe. Libertarianism needs its own Copernican Revolution.

But if not the NAP, then what? Where is the proper moral foundation of libertarianism to be found?

That’s the question that a group of us are going to be exploring over at Libertarianism.org this week. My own essay went up this morning. In it, I claim that the problem with the NAP isn’t that it’s the wrong moral rule on which to ground libertarian belief. It’s that the search for a moral rule from which libertarian beliefs can be neatly deduced is itself misguided. What we need are principles, not rules.

Principles are not like rules. Where rules function in our reasoning like trump cards, principles function like weights. If the appli­cable moral rule forbids X, then X is ruled out, so to speak. In contrast, principles can weigh against X without categorically ruling out X.

Principles make moral reasoning messy. Their application involves judgment and discretion, and they leave room for the possibility of irresolvable disagreement between reasonable parties. Simple rules like the NAP avoid this messiness, but

while we can make our moral theory as simple as we wish, that doesn’t do anything to simplify the underlying moral facts that theory is supposed to represent. Morality – even just the sub-part of morality concerned with justice – is complicated. As libertarians, we can either ignore that complexity, pretending that considerations of need, desert, and utility are of no intrinsic significance. Or we can embrace it, and argue that our system does better than any alternative at coping with that complexity, and generating reasonable political prescriptions on the basis of all the morally relevant information.

You can read the whole essay here. More essays are coming this week from (at least) Jason Kuznicki, George Smith, Brink Lindsey, J.C. Lester, and Aaron Powell. Stay tuned!