‘Think yourself lucky,’ said my husband when I told him about poor John Stuart Mill’s mother, who had nine children by a man strongly in favor of birth control and who brought up his children ‘in the absence of love and in the presence of fear’.

Parenthetically, I have only just discovered that the Mill family name had been Milne, changed to sound less Scottish. Gladstone’s name in his youth was Gladstones. Arthur Wellesley, later Duke of Wellington, only changed his name from Wesley at the age of 29. Why are so many great men pseudonymous?

Anyway, the bad-tempered James Mill used to stay with Jeremy Bentham from 1814 to 1818 at the stupendous Forde Abbey, Somerset, where they worked in a room hung with great tapestries made from Raphael cartoons now in the V&A. For exercise, Bentham walked in the 80ft cloister-conservatory. This he called vibrating.

It was not such outlandish terminology as it now seems, for vibrate could mean ‘oscillate’, like a pendulum. In the 17th century it also meant, following its Latin origin, ‘shake, brandish’, as with a sword. The Bard might have been called Vibratespear.

Though archaic heralds still speak of a sword brandished by a lion as vibrant, we’re accustomed to vibration being the rapid tremor of sound. Only in 1993 did the Oxford English Dictionary catch up with a newer meaning of vibrant that suggested ‘vitality or the exotic’, something ‘teeming, exuberant, flourishing’.

In this sense Lord Sumption wrote in the UK Spectator last week of London after Brexit no longer being ‘one of the most vibrant places on earth’. Perhaps that may partly be through the departure of French bankers. Yet vibrancy is often attributed to the presence of black people. ‘The vibrant Black history of Notting Hill Carnival’ is the heading to a blog by the Findmypast family history team. Hackney, where ‘40 percent of the population come from Black and Minority Ethnic groups’, describes itself as ‘a rich, vibrant mix’. Historic England is honoring ‘the great contribution Black Britons have made to our vibrant and diverse society’. There it is: a long way from the dour exercise of Bentham, inventor of the panopticon prison.

This article was originally published in The Spectator’s UK magazine. Subscribe to the US edition here.