It’s with triple reluctance that one disputes anything said or written by Jonathan Sumption. First, Lord Sumption is among the commentators I most admire, with an intellect against which it must be foolhardyto pit one’s own. Secondly, as a former Supreme Court justice, his legal expertise will be immense, whereas I only read law as an undergraduate, and that more than half a century ago. Thirdly, on the merits of the government’s proposal to declare Rwanda safe for asylum seekers in UK law, and perhaps ‘disapply’ any international convention that says otherwise, I actually agree with him: I, too, doubt the wisdom of the move.

Statute has regularly done what Lord Sumption denies it has ever done – and often it must

But in a column for the Sunday Times on 19 November Lord Sumption made a most important statement; I don’t think it’s correct; it’s pivotal to this case; and as (should the Upper House consider draft legislation to give effect to the government’s proposal) their lordships may approach Sumption’s argument with grave attention, I’ll now put another point of view. Mine is that both statute and case law have regularly done what Sumption denies they’ve ever done – and that often they must.

This is what he wrote: ‘There is no precedent for changing the facts by statute and requiring the courts to accept them whether true or false.’ Really? Let us turn to Dickens.

‘That is no excuse,’ returned Mr. Brownlow. ‘You were present on the occasion of the destruction of these trinkets, and, indeed, are the more guilty of the two, in the eye of the law; for the law supposes that your wife acts under your direction.’

‘If the law supposes that,’ said Mr. Bumble, squeezing his hat emphatically in both hands, ‘the law is a ass – a idiot. If that’s the eye of the law, the law is a bachelor; and the worst I wish the law is, that his eye may be opened by experience – by experience.’

It was a fact (Oliver Twist has already make clear) that Mrs Bumble did not act under her husband’s direction. Indeed, in the preamble to this passage he made sure she was out of earshot before he dared speak. But his subordination was one of those facts that parliament had changed, ‘requiring the courts’ (in Sumption’s phrase) ‘to accept them whether true or false’.

I recall a comparable case that amused the Commons mightily. A somewhat choleric Tory MP (who later became a Labour one) was convicted of permitting cruelty to sheep. He had not permitted cruelty to sheep. Nobody thought he had. An employee on a farm he owned had failed to feed the sheep. The MP had not known this and there was no suggestion he should or even could have known, but the Protection of Animals Act deemed owners responsible even if they weren’t. As I pointed out in a 1996 parliamentary sketch: ‘Nobody who knows this sensitive and considerate MP could imagine for a moment that Quentin Davies is personally capable of incivility to a solitary ewe, let alone brutality to a whole flock of sheep.’ Yet for the rest of his Commons career the poor man had to put up with Labour’s Dennis Skinner bleating whenever he spoke.

In fact the law was not an ass here. Statute must often define ‘responsible’ to cover circumstances where the accused was not responsible in the ordinary meaning of that term: sometimes to incentivise people at the top to keep a close eye on what their subordinates are up to; sometimes because the actual perpetrator is hard to identify, and someone must take the rap.

And while we’re on the farm, take a look at the legislation and secondary (regulatory) legislation on the slaughter of animals. Its principal aim is to minimise cruelty. Thus all slaughtermen – except Muslims or Jews carrying out the slaughter for ritual and religious reasons – would break the law if they killed an animal by cutting its throat without stunning it first. The restriction of this method to certain persons doing it for certain purposes plainly implies that the method is cruel, because it is prohibited in general use. In effect, then, the law on cruelty has been disapplied from particular individuals in particular circumstances. I’m not defending or criticising here: simply pointing out an obvious case of disapplication.

The ease and frequency with which both statute and case law can ‘change the facts’ lies in the law’s power to define words. Its power to change their ordinary usage is weak, but its power to redefine them for the purposes of the law is total. It can call black ‘white’ – or, rather, call Japanese people whites, as South African apartheid laws did. It can turn mistaken identity into rape. It can call scaring somebody an assault, or touching their bottom an indecent assault. And as we’re reminded in Budget statements, the law can make biscuits of things that are not biscuits, and ‘basic necessities’ of tampons but not toilet paper.

Lawmakers restrict as well as distort or extend meanings. Recently the government tried to redefine ‘pollution’ as not applying to pollution by housing development – failing because parliament did not want to exempt house-building, not because it couldn’t. And it’s now more than 50 years since a section of the Road Traffic Act (1972) stipulated that ‘any person’ who didn’t wear a crash helmet while on a motorcycle would commit an offence – and 48 years since an amendment made clear that ‘any person’ did not ‘apply to any follower of the Sikh religion while he is wearing a turban’. Nor is a Sikh person a person for the purposes of safety-at-work legislation, where helmet compulsion has also been disapplied, though religion does not protect the head.

A word, said Humpty Dumpty, ‘means just what I choose it to mean – neither more nor less’. Like Humpty, the law can disapply the designation ‘unsafe’ from Rwanda without departing in any way from legal precedent. Whether it should, Milord, is a question of public policy, not jurisprudence.