Boris Johnson has discovered the advantages of brevity. It is not only a good idea, at PMQs, to ask brief questions, which give the PM the minimum time to think.

It is also a good idea for the PM to give brief answers, by saying yes to whatever part of the question lends itself most readily to a whole-hearted affirmative, while ignoring the rest of it.

So when Derek Thomas (Con, St Ives) asked to come and see the Prime Minister about the shortage of dentists in Cornwall, Johnson just replied: “I’m very happy to meet my honourable friend at any time.”

The dental aspect of the question had been avoided, or postponed, but everyone was happy. Thomas can tell his constituents he is seeing the PM, and the rest of us have not had our time wasted by hearing Johnson expatiate on the importance he attaches to the welfare of Cornish teeth.

Jeremy Corbyn produced a Tory cheer by declaring, “This Friday the UK will be leaving the European Union.”

More happily, Corbyn remembered the late Nicholas Parsons. Johnson agreed, unrealistically, that it was good to avoid hesitation, repetition or deviation.

Caroline Lucas, for the Greens, proceeded to raise the bar to a quite impossible level by demanding an end to hypocrisy. She said Britain will not be taken seriously until it stops ploughing foreign aid into the development of fossil fuels.

Johnson tacked the easy bit of this, assuring the House that “not one penny will be going into digging out coal”.

He said no word about hypocrisy, without which politics would become unsustainable. No politician can avoid the need to don at frequent intervals the mask of virtue, and pretend to an even greater devotion to carbon neutrality, or dental services in Cornwall, than he or she happens at that particular moment to feel.

Siobhan Baillie (Con, Stroud) invited Johnson to come and see “our famous flamboyant flamingos” at Slimbridge, in her constituency.

This was not a difficult question. Johnson said he would love to come and see her famous flamboyant flamingos at the earliest opportunity.

Here is a can-do PM, who points out when Corbyn is being “negative”, but does even that in an almost affectionate manner.

The Speaker, Sir Lindsay Hoyle, delivered a short statement in which he promised, in effect, not to behave like his predecessor, John Bercow, and defy standing orders.

Oh brave new world, that has such people in it.