On: MPs seek to overturn ruling that stops police being sued for failings

A member of parliament wishes to shield the constable from the citizen’s suit, and his colleagues mean to take the shield away. I confess I read the matter twice, thinking I had misread it the first time.

Here is the plain arithmetic of it. A trade that cannot be sued for bad work soon does bad work. The printer who may libel with impunity libels; the cooper who may sell leaky barrels sells them. This is not philosophy, it is the observation of any man who has kept a shop. Accountability is not a punishment visited on the tradesman - it is the whetstone that keeps the edge. Take it away and the blade dulls, however fine the steel.

Now the honest counterargument, which I must state fairly or be a partisan fool: an officer sued at every misstep may grow timid, and a timid constable is of small use against a bold thief. There is truth in it. But the remedy proposed - that dishonesty and fabricated evidence enjoy the same shelter as honest error - confuses two very different goods. A man who trips deserves forbearance. A man who trips and swears he was pushed deserves the magistrate’s full attention. To wrap both in one blanket is to teach the second man that lying is a kind of clumsiness.

The parliamentarians, it seems, agree, and mean to trim the blanket. Good. I only note how long the trimming took, and how many citizens paid for the delay.

I am an old man and have been governed by worse, so my astonishment is modest. But I remark that every institution I ever helped raise - the fire company, the library, the watch - improved in exact proportion as its mistakes could be named aloud and paid for. Silence is cheap in the short ledger and ruinous in the long one.

Let them amend it, then measure whether the thieves grow bolder. That is the whole experiment, and it costs nothing but honesty to run.