What role, if any, should contrarians play in public life? This is the question posed by the appointment of Sir Roger Scruton as housing tsar despite (or perhaps because of) his unconventional opinions on eugenics, date rape and gay rights.

The issue here is not a left-right one. We could ask the same question of John McDonnell: does his support of the IRA disqualify him from office? Scruton

In fact, for me the analogy is a quite close. Both men have valuable ideas. McDonnell’s ideas on fiscal policy and worker ownership are good. And Sir Roger is a rare rightist who can (sometimes) think and write well and who is fascinating for being a conservative whose mind isn’t addled by Brexit or free market simplicities: I’d recommend his books Gentle Regrets and England: an elegy. (Perhaps there’s another parallel; both men’s most deplored utterances are the products of their class, age and environments.)

The case for excluding such men is that the expression of bad ideas itself betokens a lack of judgment. Just because you believe something does not mean it should be said. The ability to shut the fuck up is much to be prized.

But, but, but. Excluding such men doesn’t just risk depriving us of talent. If people know that heterodox ideas will carry heavy costs we’ll end up with men falsifying their preferences – using politically correct language to disguise racist or sexist behaviour: Harvey Weinstein, remember, has been a keen supporter of liberal causes.

What’s more, if we select people for having uniformly orthodox opinions we’ll end up not with office being held by those with phronesis, but by poker-up-the-arse careerists who are too dull or stupid to challenge our managerialist conventional wisdom. One McDonnell or Scruton is worth a dozen of them.

Everybody is irrational about some things. Scruton and McDonnell join the long list of people such as William Shockley, Richard Dawkins, Larry Summers, Vicky Pryce, Bobby Fischer, Glenn Hoddle and James Watson – people of brilliance who also have made some terrible decisions. If you’re looking for people of uniformly sound judgement, you’ll find nobody but crooks, dullards and disappointments. In this context, I'd rather judge people by their best rather than their worst.

And then, of course, there is Mill’s famous point – that we need contrarians, even if they are wrong, to sharpen our perception of the truth:

The peculiar evil of silencing the expression of an opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error.

Note that the silencing here need not be legal suppression; it could be via the tyranny of the majority, or simply self-censorship.

But again, there’s a but. Contrarians don’t always (or even often) provoke intelligent debate. They can be as tiresomely conformist as the dullest careerist: is there a more predictable writer than Brendan O’Neill?  And what looks like contrarianism is often no more than mindless tribalists whining about political correctness gone mad zzzzz: despite my analogy, how many defenders of Scruton would also defend McDonnell?

If all this sounds inconclusive, that’s because it is. My hunch is that Scruton should not be housing tsar not so much because of his regrettable ideas on some things, but simply because his merits do not extend to especial expertise on housing. This, though, does not solve the underlying questions: how tolerant should we be of otherwise useful people in public life who say things we hate? What is the proper place for those who question society’s flawed conventional wisdom? What, if anything, can we do to get a better and more diverse type of contrarian?