There’s a price to pay for our

An exhibition on the darker side of life forces us to confront our appetite for immorality however well behaved we think we are, says David Aaronovitch.

THE only time I got sent out of class in the sixth form was in an argument about Henry IV. Our excellent but irascible teacher was keen to establish that Shakespeare intended the riotous Falstaff to be regarded by the audience with disapproval. I challenged him. Why, in that case, had the bard made Sir John the most attractive figure in the two plays? He might constitute a guilty pleasure, I said, like picking a large scab, but who didn’t brighten up when that ‘‘swollen parcel of dropsies’’ appeared on stage? My teacher demurred and that was my English class over for the day.

That moment came back to me with news of the forthcoming exhibition on the theme of sin at the National Gallery in London. Its curator, Dr Joost Joustra, announced they would be taking works from the Renaissance onwards, from depictions of Adam and Eve and original sin, to Tracey Emin and evenmore-original sin.

My first thought was ‘‘that’s a crowdpleaser’’. My second was that they would never put on a show entitled Good People: virtue in art across the ages. Apart from the odd church group, no-one would go.

Virtue, like happiness, seems flattening. ‘‘All happy families,’’ wrote Tolstoy at the beginning of Anna Karenina, ‘‘are alike; each unhappy family is unhappy in its own way.’’ The kind of gossip that gets people whispering deliciously in corners (or so I’m told) is far more likely to involve stories of moral turpitude on the primrose path than of strong-minded acquaintances sticking to the straight and narrow. ‘‘You know Moira?’’ ‘‘Oooh what?’’ ‘‘She’s staying with her husband!’’ ‘‘You don’t say!’’

So what does goodness consist of? Looking for someone defining civic and personal virtue, I came across this, from the Boy Scouts of America. The Boy Scout Law lays down that ‘‘a Scout is: Trustworthy, Loyal, Helpful, Friendly, Courteous, Kind, Obedient, Cheerful, Thrifty, Brave, Clean, and Reverent’’. And here I’ll ask readers to hold this list in their minds, perhaps trying not to be distracted by the injunction to be clean. Anyway, we’ll come back to the Law later. Let’s agree for the moment that it all sounds rather pious.

In the Prado in Madrid there’s a painting by the 16th-century Venetian artist Paolo Veronese. Entitled Young Man between Vice and Virtue it shows a youth making a choice between two women. One is in a state of undress and is smiling, one is cloaked and severe. And I know which one I prefer.

My favourite nude woman in art will be in the exhibition. A few years older than Veronese, Lucas Cranach the Elder managed to paint both his friend Martin Luther and the goddess Venus. In his Venus and Cupid, Cupid is a cherub carrying a honeycomb in his hand but is crying because bees are stinging him. His mother, Venus, is an alabaster-skinned vision, wearing only a large fur-trimmed hat and a thick gold necklace. And she is taking no notice of the child but, half-smiling, is looking directly at me . . . sorry, at us. Older readers will remember the US president (and evangelical Christian) Jimmy Carter confessing once that he had committed adultery in his mind. Well, it’s a bit like that. She sins, we sin.

As it happens, the most remarkable picture to feature in the exhibition also has a naked Cupid and a naked Venus in it. Painted in 1545, An Allegory with Venus and Cupid is by Agnolo di Cosimo (called Bronzino) and the chances are you’ve had a postcard of it.

Bronzino’s Cupid is adolescent and is embracing his mother, kissing her on the lips. His fingers are caressing a nipple that seems (shall we say?) interested. This is incest, of course, but it’s also Greek myth and given the various ways and guises in which Zeus rapes his victims, a bit of consensual Cupid-on-Venus action seems less shocking.

To the right of the couple there stands another naked boy, smiling and about to scatter rose petals on the pair. It may be naughty, this picture, but everyone seems happy enough. You may easily overlook the word ‘‘allegory’’ in its title.

Liquor may be quicker, as the adage nearly goes, but vice is nice. Or, at least, engaging. In The Third Man the most

The kind of gossip that gets people whispering deliciously in corners is far more likely to involve stories of moral turpitude on the primrose path than of strong-minded acquaintances sticking to the straight and narrow.