In the course of a fascinating post in which he discusses Geoff Pullum's claim that there is a kind of third way between linguistic descriptivism and prescriptivism, Glen Whitman wonders about the relative merits of internal versus external normative critique of systems of social rules. In the process, he quotes the ubiquitous Uncle Fritz (from LLL, vol. II), and then comments:
If we are to make full use of all the experience which has been transmitted only in the form of traditional rules, all criticism and efforts at improvement of particular rules must proceed within a framework of given values which for the purpose in hand must be accepted as not requiring justification. We shall call ‘immanent criticism’ this sort of criticism that moves within a given system of rules and judges particular rules in terms of their consistency or compatibility with all other recognized rules in inducing the formation of a certain kind of order of actions.
Hayek’s argument hinges on two aspects of his thought – first, his severe doubts about the ability of human beings to fully comprehend the functionality of their social norms (an epistemological position); and second, his belief in an imperfect but usually beneficial process of cultural evolution. If one doubts either of these positions, external critique might seem more sensible.
I agree with Glen, but there's more to the point of internal critique than just this, I think.
Hayekian immanent criticism bears a close resemblance to Rawlsian reflective equilibrium (RE). I believe the most overlooked aspect of Rawls account of RE is that the raw material for reflective moral deliberation flows from from the same capacity that accounts for moral motivation. If we use commitment A to criticize commitment B, and vice versa, and end up with a new commitment C, we can marshall the motivation associated with our initial commitments into the service of C. The problem with external criteria of the right is that they may have no connection to the commitments that govern our moral motivation. The external criterion may tell us that we ought to have commitment D. But there may be no plausible psychological path from here to there. So a system of rules constructed according to an external criterion (the principle of utility is an excellent example) will be regarded by actual people as alien and offensive to their moral sensibility, and will not gain their willing compliance. A system of rules arrived at through a process of reflective equilibrium or immanent criticism will generally have a connection to our prior tendencies of judgment and motivation, and will therefore be more likely to gain willing compliance, and will therefore more likely be stable and viable as a system of rules for real people.
Reliance on immanent criticism is, I believe, a hallmark of a genuinely liberal, non-utopian cast of mind. Because people don't like to comply with rules generated by external criteria — because we don't recognize them as binding — those committed to these criteria may get it in their heads that the little people need to be forced to follow the rules, or have their moral sensibility “re-educated.” For their own good, of course. In this respect Rawls and Hayek are very much on the same liberal team against socialists too much in the grip of an external theory about an optimal order.
NB: the line between a highly refined and developed internal critique and an external one is fine indeed.