In responding as they did to the Daily Telegraph ‘sting’, Jack Straw and Sir Malcolm Rifkind may well have done nothing wrong by the letter of parliamentary law. But people’s perception of behaviour is quite another matter. The MPs’ bloated self-importance and Rifkind’s shameful defence of his actions, that no one would want to become an MP unless they could also line their pockets, did them no credit at all.

The ancients knew all about this sort of thing. Roman senators, for example, made millions if they were posted abroad to run provinces. As cynics said, they had to make three fortunes: one to recoup election expenses from climbing the greasy pole; one to bribe the jury on charges of provincial mismanagement; and one to live off in exile thereafter.

On the other hand, the Athenian orator Hyperides (389-322 BC) suggested that there was a distinction to be made between those statesman and soldiers who made large profits simply to enrich themselves and those who did so in the interests of the people; while the Athenian Democritus (5th century BC) pointed out that, if you wanted to strengthen concord in the community, there was nothing like the rich giving to the poor.

Cicero went even further in his unpublished de legibus (‘On Laws’), composed while the republic was collapsing in the 40s BC. Arguing in detail how the state should be ordered, he pointed out the heavy responsibility the Senate owed to the people they ruled: ‘The senatorial order must be untainted by impropriety and serve as a model for the rest of the citizens. If we can secure this, we shall have secured everything … it is not so much that our leaders do wrong, though that is a great enough evil in itself, as that they encourage so many imitators … I believe that a state’s character is transformed by the habits and way of life of its leading men.’

That is the central problem raised by the Straw-Rifkind ‘sting’ — how to appoint as MPs men of integrity as well as ability who will set an example to those they govern.