First of all, let me extend my sincere gratitude to everyone who’s participated in the conversation so far.  It’s been great.  It’s been, in fact, overwhelmingly great.  I’m stunned at the quality of the participants, and of the resulting dialogue.  And I can’t wait to see where it goes from here.

Some of the discussion, however, leads me to think that it would be fruitful to say a few more things about the relationship between libertarianism and social justice.  Much more would need to be said about each of these topics, and many more besides, to provide a fully satisfying philosophical account, let alone a justification.  But I hope this will move us in the right direction.

1. Moral standards vs. Public Policies – When I talk about social justice – and I think the same is true for Jason, though I’ll let him speak for himself – I’m talking about a moral standard by which various public policies or larger social/economic/political institutions might be evaluated.  To be committed to social justice is to hold that a policy or institution must, in some way, work to the interest of the more vulnerable members of society in order to be morally legitimate.  Suppose you sign on to this idea.  If so, there’s still a long way to go before we figure out what policy proposals are justified.  You can’t automatically infer that progressive, redistributive taxation is justified merely because it is intended to help the poor because, simply put, it might not actually accomplish that goal.  To know what policies satisfy your moral standard, you have to look at the facts – at how the world works.  So while the ultimate moral principle is independent of economic analysis, the policy/institutional implications of that principle are not.  I, for instance, have spent a good deal of time arguing that concern for the vulnerable entails rather counter-intuitive public policy positions on issues like sweatshops and price gouging.  People on the left who read this sometimes conclude that I must hold radically different moral principles than they do.  But part of the point of bleeding heart libertarianism is to show that this is not necessarily the case.
2. Social Justice as a Foundation and Limit to Libertarianism — So social justice, as I see it, is an important part of the overall moral standard by which public policies and institutions are to be assessed.  Because my views on how markets and politics work are heavily informed by the likes of Hayek, Mises, Buchanan, and Tullock, I think that a commitment to social justice, combined with the relevant empirical facts, justifies a set of policies and institutions that are much more libertarian than most of my colleagues would suppose.  Social justice is thus part of the justification for libertarianism for me.  But it also sets sharp limits on the extent to which libertarian policies are justified.  If it turns out to be the case that libertarian policies don’t work to the advantage of the vulnerable in some range of cases – perhaps because you’re concerned about various forms of market failure or individuals slipping through the cracks of civil society’s charitable efforts – then you’re going to want to hold, like Adam Smith, Friedrich Hayek, Milton Friedman, Richard Epstein, etc., that certain kinds of government intervention in an otherwise purely free market are warranted.  Where those limits lie will, as above, be a product of both your foundational moral commitments (that social policies must work to the advantage of the vulnerable, for instance) and your empirical beliefs (about the extent and scope of market failure, for instance – which failures I realize are often badly overstated, but which nonetheless exist and have important implications, it seems to me.
3. Why Believe in Social Justice?  I’ve defined a commitment to social justice in a very broad and unsatisfactory way – as a commitment to the idea that social policies and institutions must work to the advantage of the more vulnerable members of society.  More needs to be said.  But before we go on to fill in the details, why would someone think that this ought to be part of the moral standard by which social institutions and policies ought to be evaluated?  Here, it seems to me, defenders of social justice can point to an “overlapping consensus” of sorts.  There are lots of reasons, from lots of different perspectives, for taking social justice seriously.
   1. Rawlsianism – Jason Brennan and John Tomasi frame their position as one that develops and corrects the moral insights of John Rawls.  To my mind, they take too much of Rawls’ problematic machinery on board.  But they’re not the first to try to support classical liberalism in this way, and I have been favorably impressed by at least one previous attempt.
   2. Consequentialism – But one could support social justice from a consqeuentialist perspective as well, especially if one takes the kind of prioritarian position advocated by my friend Richard Arneson seriously.  A consequentialist approach that is both choice-sensitive and luck-insensitive seems to be a good foundation to defend a number of positions that classical liberals and libertarians endorse.
   3. Public Justification – It is arguably a core commitment of liberalism that the public use of coercion must be justified to those against whom it is imposed. But property rights are a kind of coercion.  The kind of coercion they involve is probably a morally justifiable sort, but it is coercion nonetheless.  If that’s the case, then we need to be able to justify property rights, and the larger economic and political frameworks in which they operate, to everyone.  Including the poor.  This, I take it, is what Gerald Gaus is up to in his fascinating work on justificatory liberalism.  And it’s quite similar to what Loren Lomasky was up to in his Persons, Rights, and the Moral Community.
   4. Religion – For those who seek their morals elsewhere than the airy heights of philosophy, religion can also provide a source of support for social justice.  The principles of Catholic Social Teaching, for instance, support a preferential option for the poor.  What this means in practice is something, I think, that should be better informed by good economics than it sometimes is.  But the moral principle itself is squarely in line with the idea of sociall justice as I have been describing it here.