Overlapping Consensus Libertarianism or Why Convergence Arguments Are Cool


Hello blog readers. Like my fellow bloggers I am stunned and grateful for the attention our blog has generated. I am also tickled that my suggestion for the name of the blog was chosen.

Many people wonder about and are concerned about the foundations or justification of libertarianism or classical liberalism. My view is that worry about the foundations of classical liberalism is misplaced. Here I present a method of justification that Matt Zwolinski calls overlapping consensus libertarianism in his excellent overview of libertarianism. See

   The idea an overlapping consensus comes from John Rawls in Political Liberalism. To quote Zwolinski, “Rawls’s idea is that decisions about which political institutions and principles to adopt ought to be based on those aspects of morality on which all reasonable theories converge, rather than any one particular foundational moral theory, because there is reasonable and apparently intractable disagreement about foundational moral issues.”  Applying this to libertarianism, rather than looking for one or the best moral or political theory, one grounds libertarianism by showing it is compatible with a variety of reasonable approaches.

    The advantage of this kind of approach is that one avoids the house of cards problem. Put all your effort into showing that one kind of political theory is the correct view, and supports certain principles or institutions, then if it turns out your theory is mistaken, you have no support for your principles or the institutions you support. But if your principles or institutions are supported by a wide variety of political theories or perspectives then you avoid this problem. The wider the variety of approaches that support your favored principles or institutions the better.

In my book Is the Welfare State Justified? I used this kind of approach–which I called convergence arguments–with a special twist. I argued that the predominant or mainstream nonlibertarian perspectives in contemporary political philosophy–e.g.,egalitarianism, prioritarianism, communitarianism–should converge on supporting more market-based or libertarian institutions than they realize. While these perspectives think that their political principles or values support central welfare state institutions (social insurance programs, government welfare) I argue that they are mistaken. When one compares how welfare state institutions actually work compared with how more market-based alternatives actually work the latter are superior from the standpoint of the dominant perspectives in contemporary political philosophy. (The kind of argumentation I used in my book involves doing comparative institutional evaluation, which means combining political philosophy with social science, a point I will return to in a later post).

    Notice that the kind of convergence arguments I described above do not challenge nonlibertarian political principles or values. I think that there are two things to be said for this. First, it’s hard to change people’s minds that their basic political principles or values are mistaken.  Second, it gets the debate focused on to me what is the central issue between libertarians and their opponents, namely what kinds of institutions we should have. Classical liberalism, or libertarianism should not be identified with a certain way of arguing for limited government, free markets, etc., but rather with support—from a variety of standpoints—for those institutions.

Published on:
Author: Daniel Shapiro
  • Many roads lead to liberty. I have long said so.

  • Dan Kervick

    As a method of argumentation in the public sphere, the overlapping consensus approach is unexceptionable. If one can indeed show that some collection of widely held moral/political theories T1, T2, T3 … Tn all agree, in combination with some body of empirically confirmed social observations, in recommending institution X, then that is certainly an effective means of securing assent for X in a pluralistic society whose people happen to hold a variety of different fundamental views.

    But one can hardly take that as an argument for any one particular theory. So I don’t see how you can think of this theory as a method of justification for libertarianism, or a way of grounding libertarianism.

    It is true that if one has prior reason to believe institution X is commendable or ought to be established, then one can think of an overlapping consensus argument as providing confirmation for each of the theories T1 through Tn. But this doesn’t seem to be the approach you have taken, since you say your arguments in the book are designed to persuade people to endorse institutional arrangements that they don’t already accept.

  • Kervick:

    The approach does not require first choosing a position and then showing how many views support it.

    A complete version of the project would require that one do this completely. How do all policy positions pan out?

    You don’t have to start off with market oriented reform, can it be justified on a variety of grounds.

  • Dan, two points:

    1. I use convergence arguments in my book to support market-based institutions, not to support any particular political theory.

    2. The way I argue in my book to persuade people to accept institutions they oppose is to argue that the institutions are supported by their political principes or values. So it’s their own theoriese that show support for the institution.

    Hope that helps.

  • I like this! Exposing the Nirvana Fallacy seems key here. It’s a powerful approach.

  • (Apologies for chiming in late; this is a great blog, but keeping up with the posts *and* the comments is exhausting.)

    Your approach puts me in mind of the reciprocity principle advocated by Amy Gutmann and Dennis Thompson in their book “Democracy and Disagreement”, i.e., “to justify public policy by giving reasons that can be accepted by those who are bound by it”. The major difference seems to be that Gutmann and Thompson are concerned with issues concerning which there is real moral disagreement e.g., abortion), while in the cases you discuss the moral disagreement is often more apparent than real.

    (But I think showing that moral disagreement is only apparent and that a mutually-acceptable policy exists is best done by an approach like this where you can take opponents’ principles at face value and argue from there. If I recall correctly Gutmann and Thompson make a similar point about the virtues of using the reciprocity principle.)

  • @ Frank–thanks for the point about Guttman and Thompson. It’s been a while since I read them.
    @ Sheldon–Yes, and in another post I will tie in my remarks above with the Nirvana fallacy.

  • Given that “Democracy and Disagreement” is the only political philosophy book I’ve read all the way through, I glad I had occasion to name-check it 🙂

    The funny thing is that based on my own experience Gutmann’s and Thompson’s approach seems much more relevant to libertarian contexts than to traditional democratic politics. For my take on this see

  • Pingback: A Bleeding Heart Libertarian Manifesto, Of Sorts | Bleeding Heart Libertarians()