Why do some rightists oppose mandatory face-coverings? Tory MP Desmond Swayne has called them a "monstrous imposition", Peter Hitchens says they leave us "muzzled in face-nappies" and of course James Delingtwat and Laurence Fox have jumped on the bandwagon - although Mr Fox has at least the redeeming virtue of possessing some talent.

I don't think the anser lies in the proposition that there's little evidence of masks' effectiveness. For one thing, there is. For another, risk is not merely a matter of facts but of feelings, and common sense says that masks reduce the risk of infection. And for a third, rightists are not always fastidious about following evidence. (Hint - the B-word).

Instead, I suspect something else is going on. Mask-wearing shows that the fulfilment of our preferences is not compossible, to use Leibnitz's word. My preference not to wear them (being a speccy four-eyes they steam up my glasses) conflicts with the shop-worker's preference to feel safer.

Now, in some some just-so stories, such non-compossibility doesn't happen. In Adam Smith's fable of free markets his preference for dinner and the butcher's preference for a shilling are indeed compossible.

Mask-wearing shows us that the world isn't always like this. Preferences conflict. And when they do, we leave the realm of perfect markets and enter politics. Politics is what happens when my neighbour wants a quiet night and I want a party. My initial thought, then, is that what we have here is an example of libertarian rightists being anti-politics. They fail to see that the fairytale libertarian world of compossible preferences is not always feasible, and rather than adapt their thinking they rail against politics.

But this isn't quite right. Some anti-maskers are anti-libertarian. Mr Hitchens is a long-time campaigner against drug legslization, and Mr Swayne has voted to maintain the criminalization of cannabis use. Both therefore fail a litmus test of libertarianism. Conversely, some of the smarter libertarians, such as Ryan Bourne, are pro-mask.

This isn't, then, a matter of libertarianism. Instead, I suspect anti-masking is a continuation of a recent strand of mainstream Toryism - a refusal to see problems of collective action, whereby preferences are not compossible.

Back in 2012 there was a burst of panic-buying of petrol for fear of a strike by fuel drivers. David Cameron responded by saying: "If there is an opportunity to top up your tank if a strike is potentially on the way, then it is a sensible thing if you are able to do that." But this exacerbated the panic. Cameron failed to see that preferences were not compossible. My preference for a full tank just in case of a strike conflicted with yours.

And this was not an isolated example. Quite the opposite. Tory-Lib Dem policy in 2010-15 was founded on just such an error. Preferences for "sound public finances" conflicted with firms' and households desires to save. The upshot was weak growth and a failure of austerity to reduce government borrowing as much as hoped. That was the paradox of thrift. And incentivizing people to want to move off benefits led not so much to higher employment as to tougher times for claimants.

In cases such as these, preferences are not compossible. Sometimes, when we all act on our preferences, we end up collectively worse off. Wearing masks is the flipside of this: by acting against our preference and wearing them, we might end up collectively better off by having fewer infections and escaping lockdowns. I don't often praise him, but Mr Johnson is to be congratulated for seeing what his fellow Etonian did not, that the essence of politics is to solve collective action problems.

Not all rightists, however, do grasp this fact. In failing to do so they are not so much being individually stupid as merely following one of the dafter trends in recent Tory politics.

I stress that word "recent". Tories have not always been blind to the need for some people to make sacrifices for the greater good when preferences conflict. For decades, they've urged tougher conditions for workers and claimants for the "greater good.", When they themselves have to make the sacrifices, some of today's Tories get queasy. For them, sacrifices are for the little people.

It's as if they actually want to prove Corey Robin right, that Conservatism stands for no more that the protection of privilege.