You might think that cases involving criminals would not give the judges much scope to develop the law. We have to go back to 1961 for the last occasion on which senior judges created a brand-new crime. As Lord Bingham confirmed in 2006, ‘there now exists no power in the courts to create new criminal offences’. But creating or extending defences is quite another matter.

The Ladies’ Directory

Shortly after the Street Offences Act 1959 made it unlawful for sex-workers to solicit in the street, a man named Frederick Charles Shaw had the idea of publishing an illustrated booklet in which they could advertise their services. Nowadays, of course, he would have built an app. Shaw was charged with conspiracy ‘to induce readers thereof to resort to the said advertisers for the purposes of fornication and of taking part in or witnessing other disgusting and immoral acts and exhibitions, with intent there by to debauch and corrupt the morals as well of youth as of divers other liege subjects of Our Lady The Queen and to raise and create in their minds inordinate and lustful desires’.

According to the charge sheet, this was a conspiracy to corrupt public morals. That was said to be a common law misdemeanour, or common law offence as we would now call it. Prosecutors pointed to a number of cases from the 17th century onwards which were said to recognise the crime of corrupting public morals. But none, of course, covered the publication of a booklet with telephone numbers.

Shaw was convicted and sentenced to nine months’ imprisonment. His appeals against conviction and sentence were dismissed by the Court of Appeal. In 1961 he appealed to the House of Lords, at that time the highest court in the land.

Viscount Simonds was the senior law lord, and readers will remember from Chapter 1 that he professed to support a much narrower approach to law making than his colleague Lord Denning. ‘Need I say,’ asked Simonds, ‘that I am no advocate of the right of the judges to create new criminal offences?’