Over the last week, I’ve been mulling over our extended discussion of public reason liberalism. In response to Andrew’s post, I thought I’d try to distinguish between contract liberalisms (of which PRL is a variant) and alternatives to further focus on what is at stake.

I’ll begin with assumptions liberals share. Perhaps the definitive moral assumption of liberal political philosophy over the last three hundred years is that all human beings are free and equal. For the great social contract theorists, to say that people are free and equal is to say that no one has natural authority over anyone else. No one gets to be the boss for free.

This does not mean that all of our obligations to others must be voluntarily assumed, nor does it mean that people are permitted to do whatever they like. The ideas of freedom and equality determine how people may direct others. Specifically, it means that no one can issue authoritative directives to others without a justification that those who are expected to obey accept (or have reason to accept, or reasonably accept in the broad sense of ‘reason’, i.e., not necessarily the ‘public reason’ sense).

But let’s be clear: it is a relatively modest claim. That persons are naturally free and equal says almost nothing about the content of morality and makes no claim that persons have equal rational capacities, that shares of income should be distributed evenly, etc. At its root, the idea of freedom and equality is simply that no one owes obedience to others without justification.

My claim should not be controversial. It’s a prominent assumption in the works Hobbes, Locke, Rousseau, Kant and arguably spans the entire utilitarian tradition. It’s a core assumption among Rawlsians and other political liberals, but it is widely shared by comprehensive liberals as well.

Liberals disagree when we ask what counts as a justification for moral and political authority. We disagree about what makes it true that we have duties to obey the demands and commands of others. To put it another way: what sort of reason could demonstrate that free and equal persons must obey one another, even in the most innocuous ways (keeping a contract, for example)?

What differentiates contract liberals from all others is their insistence that justifications must take a subjective form. The justification must be in some way one that the person imposed upon can rationally access. The family of contractarian and contractualist liberals earn the name due to this condition.

Other liberals allow that political authority can be justified in purely objective terms. They don’t mind subjective justifications; in fact, they might like them quite a bit. Their distinguishing characteristic is holding that a justification for political power might be one the person imposed upon cannot rationally access. For example, a perfectionist liberal holds that political authority is justified when it makes people better off (subject to standard rule-consequentialist caveats and conception of human welfare), regardless of citizens’ rational commitments.

After mulling it over, I think this is what divides contractarian and public reason classical liberals (like me, Jason and our friends and teachers John Tomasi, Loren Lomasky and Jerry Gaus, along with Jan Narveson and, perhaps most importantly, James Buchanan) from more traditional libertarians (like the Big Five: Rothbard, Mises, Hayek, Rand and Friedman and contemporary libertarians like Eric Mack, Michael Huemer, Roderick Long, Douglas Den Uyl and Douglas Rasmussen and I’d bet most libertarian political philosophers). Many of our lovely commenters side with traditional libertarians even if they disagree with these figures on other matters.

You don’t get out of this debate by being an anarchist. First, even if you deny that political authority exists, surely you have a view about how political authority could come into being. I don’t know any libertarian who has claimed that political authority is conceptually impossible. Second, even if you’re a market anarchist, you think that property owners have political authority to direct trespassers to leave them alone. But how is that authority justified? Can the justification be objective? Or must it be subjective?

For what it’s worth, I side with the contract libertarians because I cannot see how we treat one another as free and equal if we order each other around merely on the basis of objective reasons. Our natural freedom and equality entails that we can’t resolve our disputes about how to order social life based on one person’s disputed conception of the good and the right. It won’t do to tell your free and equal fellows that they should obey your directives (even regarding your property) merely because there exist reasons to obey you that they may or may not be able to grasp. That strikes me as disrespectful and obnoxious browbeating. I think that’s what Hobbes, Locke, Rousseau, Kant and Rawls believed as well. I know that’s what Buchanan, Narveson, Lomasky, Gaus and Tomasi think.

Those on the “objective justifications” side raise a number of familiar objections. They deny that social life can depend on mutually acceptable arrangements give how much people disagree. And they think that restraining yourself from acting on objective reasons is irrational and immoral if you in fact know the truth.

Incidentally, the contrast between the two forms of libertarian liberalism is apparent in John Tomasi and Matt’s Cato Unbound post and Roderick Long’s response.