Jake and Dinos Chapman were in entertaining form this morning. Where Sarah Montague saw hell in their new installations, they saw happiness. Where she saw Nazis, they saw royalty. For models of children with genitals for facial features, they had... well, I'm not quite sure what, because at that point in the interview, their banter fell into the gnostic art-speak of contemporary conceptualism.

Job done, you might say. They'd wrong-footed Montague, who excused their game by chuckling at the tomfoolery. But it felt to me that there might be something more sinister at play.

Denis Donoghue put his finger on it in his Reith lectures of 1982. (It's an old game.) In the third, he began: 'We cultivate, these days, a merely spectacular relation to ideas and attitudes: we watch them as they pass, as in a Lord Mayor’s parade.'

It's an attitude of irony that treats everything with equal nonchalance. Hell is equivalent to happiness. A Nazis to a prince. Children with whatever. Ha, ha. 'So we hear words like beauty and truth as if they had inverted commas around them,' Donoghue continues.

So far, so jolly. But there's a twist because 'the play of mind doesn’t make available even the possibility of a shared understanding of the object: it’s an act of power, not of communication. All you can do with a play of mind is to watch its performance.'

That felt close to what the Chapmans were up to. By resisting every shared understanding of their objects, they embark on a performance of power with the parameters set by them to ensure that they can't fail to win. It's as if the tyrants aren't being depicted in the gallery. They're the ones exhibiting in the gallery.