A while ago, for a series of not particularly interesting reasons, I read parts of Lord Devlin's criticism of the Wolfenden report, 'The Enforcement of Morals' . Amazingly, I think Lord Devlin was batsh*t crazy. His argument was essentially that legalizing homosexual acts between consenting adults would lead, by undermining the bonds that held society together, to total social breakdown. In my view, it's this kind of thing that gives conservatives a bad name, which perhaps means it should be encouraged. No empirical evidence for this claim is adduced: in particular, it is not explained why the then illegal homosexual acts between consenting adults do not themselves cause total social breakdown. Neither is any alternative to imprisoning people for voluntarily committing acts which do no harm - beyond the dubious harm of the offence, an offence which occurs anyway, since making some act illegal does not prevent it occuring, or even ocurring without punishment - to anyone else. Finally, there is no argument that total social breakdown would in fact be worse than imprisoning people for what any sensible person can see they have a right to do.
All of these things are quite rightly pointed out by Colin Farrelly in his piece here. What seems odd to me is that he does not think that these are things that can be said on the basis of liberal neutrality - understood here as the requirement "that the justification for a law or policy should be neutral... [that it] should not presuppose, for example, values particular to one conception of the good", as, for example, an appeal to piety would. Farrelly seems to think that because Devlin is appealing to the value of social cohesion, which plausibly is a neutral - in the relevant sense - value, the liberal neutralist cannot say anything against his argument. What seems to have gone wrong here is that the idea that a justification for a law or policy must not only be neutral, but justificatory, or else, in an important sense, it is not a justification. The problem with Devlin's argument is that it is an awful argument: its foundational premise is radically implausible, and even if we grant that premise, it is not clear that the conclusion follows.
Farrelly quotes from George Sher's 'Beyond Neutrality' earlier on in the piece. Eleven pages after the quote Farrelly gives, Sher defines neutrality of justification, the kind of neutrality Farrelly is talking about here, stating that "[a] law, institution or other political arrangement is neutrally justifiable if and only if at least one possible argument for it (1) has only neutral normative premises, and (2) contains no implausible premises or obvious fallacies and (3) provides a justification of reasonable strength". Farrelly interprets neutrality as only requiring the first premise. If neutrality only required the first premise though, my claim that we should use all our resources to build a giant statue of me out of pure gold because otherwise the volcano which will soon appear in the middle of Oxford Street will erupt and kill us all would have to be accepted by neutralists, despite the fact that I can present no evidence for any of these claims. It would in fact be impossible to rule out any policy, because if there are no requirements on the strength of the argument as long as it comes from relevantly neutral initial premises, any conclusion can be justified by simply making terrible arguments which begin with relevantly neutral premises. Since presumably neutrality should rule something out, this cannot be plausible conception of neutrality. Obviously, Devlin's argument only fulfills the first criteria. No neutralist should worry about it, because it is a terrible argument.