A legal verdict, says Daedalus, pretends to be a certainty; but in truth it is merely a probability. Consider, for example, those plaintiffs who claim to have been made ill by silicone breast-implants, radioactivity or tobacco. Clearly it is impossible to be sure that they would not have got just as ill if they had never encountered these perils.

So Daedalus is musing on the character and process of a truly scientific court. If, for example, epidemiological evidence shows that passive smoking in the workplace increases your chance of getting lung cancer by 1%, then the judge could decide the case won if the number 100 turns up on his random number generator, but lost if 1-99 turn up. Chancy or vexatious litigants would be strongly discouraged.

It might be fairer, however, to allow an openly statistical verdict. A defendant found ‘probably guilty’ (perhaps set at 91.7% if 11 jurors out of 12 reckon he did it) might incur a fine or punishment reduced in proportion. A defendant found ‘probably innocent’ (say, 8.3% or 16.7%) might leave the court unpunished, but with a definite ‘stain’ on his character. Thereafter, until the stain was declared spent, or expunged by good behaviour, he would be literally ‘a suspicious character’ — which would tell against him if he came up again on a similar charge.

This approach would fit well into British society. British motorists already accumulate ‘stains’ on their driving licences for each small offence. Enough staining cancels the licence. The British honours system awards a ‘shine’ on the character of good eggs and praiseworthy types; if they later go to the bad, the shine can be withdrawn again. Affirmative action gives whole groups a collective shine, entitling them to jobs, presumptions of virtue or innocence, and so on.

Such an open system of honours and dishonours is much fairer than the ‘dossier societies’ run by dictators. Secret dossiers, for some reason possibly connected with the second law of thermodynamics, only accumulate evidence against their subjects. Only those faceless apparatchiks who never put a foot wrong or do anything original, flourish under them. Ominously, dossiers are now growing fast even in the democracies, in the form of credit ratings, referees' reports, compulsory secret reporting of ‘suspicious’ bank deposits, and so on. An open, numerical ‘stains and shines’ system might just stop the rot.