Theatre: The White Devil, The Swan, Stratford

It's a commonplace that, thanks to Freud and a couple of world wars, we're better equipped in the 20th century to appreciate the extremity of Jacobean tragedy than at any time since it was written. This sounds reasonable, but it doesn't stand up to the experience of seeing Webster and Middleton on stage: the gory, amoral world being portrayed may seem highly familiar, but you won't draw the same moral conclusions that a Jacobean audience did, and the charnel-house endings are more likely to make you giggle than to horrify you.

That's certainly the effect of the closing scenes of The White Devil in Gale Edwards's staging for the RSC at the Swan. You doubt that this is what Webster meant; but since there's probably no way round it, with audiences used to massive body-counts on film, it's probably best to embrace the ludicrousness of the violence, and locate the tragedy elsewhere; which is what Edwards does, and does brilliantly.

The humour and the pathos largely spring from Richard McCabe, who gives a startling depth to the central figure of Flamineo - as McCabe plays him, he's not simply a pander (pimping his sister, Vittoria, to the powerful Duke Brachiano) and a fawn, but also a jester. It's a superbly louche, funny performance, which finds a degree of cynical humour in the role that reminds you we're not so far removed in time from Restoration comedy. Beneath the servility, McCabe conveys the cruelty and sensuality that drive Flamineo, at the same time suggesting how much he has sacrificed to ambition - there's a moment of powerful sadness when, seeing his mother raving over the corpse of the brother he has killed, Flamineo observes: "I have a strange thing in me, to the which I cannot give a name, without it be compassion."

Around this mercurial, hugely enjoyable star turn, Edwards creates a sharply focused picture of Webster's post-Machiavellian world, supported by a batch of excellent performances. Here, powerful men use morality as a cover for merciless pragmatism - a point exemplified by Stephen Boxer's chilly Duke of Florence; for women the only lever available to use against such men is sex, Jane Gurnett's Vittoria is fully aware both of the power sex gives her, and how fragile that power is.

I don't want to make too many claims for The White Devil - Webster is too possessed by flesh and politics to create fully believable characters, and his plotting is execrable. But he does have eloquence, wit and moral indignation on his side; and, as this production makes clear, that's more than enough to get by.

n To 7 May (01789 295623)

ROBERT HANKS