Some will say that humour that doesn't offend isn't humour. Cutting humour is designed to draw blood. Lenny Bruce drew plenty. But there is a wide gulf between comedy and malice. The problem with the prank played on the actor Andrew Sachs by Russell Brand and Jonathan Ross is not that it was puerile. It was that it wasn't funny. Worse, it showed malice. The sort of malice shown by someone who has the courage to bully his secretary, but not to stand up to his boss.

Great humour laughs with its victims, not at them. Sachs did not deserve to be humiliated before two million radio listeners by two pranksters who allowed their celebrity to trump their judgment. Comics, especially hugely successful comics, have perhaps earned the privilege of being provocative, challenging and mischievous. Sometimes they become so intoxicated by their own fame that they can no longer police their own monologues - not for their impishness, but for their humour. That the editors of the radio show also failed to intervene to axe this tawdry segment should mortify the BBC as much as it should two of its highest-paid stars.

But having brought shame on themselves and on the BBC, these presenters could have done much to make amends by apologising, with sincerity, to Sachs. Instead, the apology given on air by Brand was undercut by his aside: “But it was quite funny.” No, it was not. It was nasty, hurtful and abusive. Does he still not see that?

Far from being an apology, Brand's remark constituted a second insult. As G.K. Chesterton pointed out: “The injured party does not want to be compensated because he has been wronged; he wants to be healed because he has been hurt.”