By Aaron Timms

Mark Sanford gave us hope. At last, it seemed, here was a man prepared to speak the obvious truth – sleeping with a new person, after decades of dun, deadening spousal loyalty, can be kind of entertaining. Here was a man prepared to junk America’s militaristic code of conjugal piety, let the hormones rip and lead his country into a golden new horizon of fish meals under palm trees, twinkling lights by the harbor, tongue kisses, tan lines and lust. But now, with David Letterman’s vaguely creepy on-air admission that he had affairs with a number of his own employees, America’s nauseating pantomime of fidelity has cleared the stage once more. The quivering chin, the glassy eyes, the looks of deep introspection into a morally charged middle distance … all it would have needed was a different backdrop and the addition of a stoutly resilient (if silent) spouse, and Letterman’s conversion into Eliot Spitzer would have been complete. Disgusting.

Usually, whenever the media in this country rips a public figure (and by public figure, I mean “man”) apart for cheating, the defences of the cheater cluster around a handful of shopworn arguments: infidelity has no bearing on a person’s performance of their professional obligations; a person’s private life should stay private; and the French don’t seem to care (“I mean, come on, dude – Mitterrand had thousands of lovers that no one knew about and he still managed to put that funny glass bit over the Louvre!”). I take issue with this kind of scandal-mongering on a different ground: Infidelity is itself a force for good. After all, at a fundamental emotional and intellectual level, what, really, is wrong with playing up? Yes, infidelity is cowardly, insensitive, disrespectful, dirty and cheap. But this is just another way of saying that it is really, really fun.

The case rests on more than just entertainment, however. In comedy and policy alike, there is a strong basis for encouraging infidelity as the guarantee of a minimum level of core competence. Sexually incriminating text messages, to take an obvious example, make for good anecdotes. Letterman owns a production company called “Worldwide Pants”: his dalliances have turned a modestly funny title into a ragingly hilarious one. The man is employed to make people laugh. By sleeping around, he has made people laugh even more. In this sense, infidelity is pareto efficient. In another sense, we should give the guy a break.

In politics, often the most terrible drunks, sleazes, self-abusers and egomaniacs make for the best legislators (exhibits-in-chief: Teddy Kennedy, Bill Clinton). Naturally the relation can be purely incidental, but my point is slightly different: a fecund, even chaotic personal life is proof of a fertile mind. It’s a fair bet that even if his early years hadn’t been studded with quick, grubby, streetside sexual encounters (“16-year-old under Etna” and “lift boy of Vauxhall”, for example, are just two of the many tantalizingly brief entries in his sex diary for the year 1911), John Maynard Keynes still would have been able to opine so magnificently on “the debauchery of currency”, craft Bretton Woods, and bequeath the intellectual machinery for virtually every developed country’s response to the current financial crisis. But the sex probably helped.

Those against infidelity want a world of quiet nights in, tedious travel stories, routine cuddling, mental stagnation and death. Those in favour of it stand for decent TV comedy, progressive legislation, monetary stimulus, life, liberty, and the pursuit of pareto efficiency.