Jumpers, Piccadilly Theatre, London

The West End premiere of David Leveaux's revival of Jumpers - now transferred from the National - coincided with anti-Bush demonstrations in London, the sounds of which were audible in the theatre. This was in piquant contrast to the television pictures we saw on stage. Set at the time of the original lunar landings, Tom Stoppard's 1972 play imagines a dystopian England where a radical liberal party has just swept to power (hence the black-and-white footage of cheering crowds), and where a perniciously pliable moral relativism is corrupting the body politic.

With the protests against the US President as a backdrop, the play was revealingly recontextualised. The juxtaposition reminded us that we have as much to fear from politicians whose belief in the existence of absolute values leads them to imagine that one of God's intrinsic and inalienable properties is that He is "on our side". A justly famous line in the play, "It's not the voting that's democracy; it's the counting", could not, in such circumstances, help but call to mind that Bush was himself not elected by a majority.

And talking of minorities, I should, in the interests of fairness, declare that my largely negative response to the evening appears to be a solo turn. To me, the play looks as dated as its conceit that man's lunar conquest would rob the moon-June-spoon type of song of its romance. As an emotionally powerful and enduring use of space travel as a metaphor for human relations on earth, Robert Lepage's Far Side of the Moon leaves this one stuck on the launchpad.

Jumpers is sometimes said to be a philosophical farce, a genre that converts ideas into action with devastating yet conceptually clarifying consequences. It is certainly true that it has a philosopher hero; the eponymous tumbling troupe of professional thinkers, who perform physical as well as mental gymnastics; and undergraduate gags with long-term payoffs, such as the maladroit use of a pet tortoise and hare to demonstrate Zeno's paradox.

But in the best examples of the genre, the propensities of farce inextricably mesh with the habits of a particular way of thinking and produce mayhem - as when Terry Johnson played with the link between the principles of Freudian analysis and trouser-dropping exposure in the hilarious Hysteria. By contrast, there is a lamentable lack of momentum or coherence in Jumpers, a deficiency not remedied by Vicky Mortimer's clumsy set, with its revolve that obligingly trundles round to reveal the study, bedroom and hall of the professor's abode. It might have been expressly designed to underline the sketchy, stop-go nature of the proceedings.

Simon Russell Beale is always worth the price of a ticket - and here he needs to be. With one possible caveat, he gives a superb performance as George, the professor of moral philosophy who is so preoccupied with his efforts to dictate a lecture on God, goodness and moral absolutes that he fails to notice that his wife (a beautiful but two-dimensional Essie Davis) is having a nervous breakdown, and that there's a dead body in the flat.

A squat figure wrapped in a shapeless brown cardigan, Beale's George brilliantly veers between a beaky, donnish self-importance and marital and professional insecurity. He lets you see both the smirking don, whose fat chops lick and relish his own bons mots, and the melancholy cuckolded egghead who knows that the yolk is on him. More than any other actor, he has the ability to make the struggle to formulate arguments sound like a passionate and accessible activity, even when the speeches are as immense and habitually derailed into farce as they are in this play.

You could quibble that the self-doubting George would not be able, even in fantasy, to try out his lecture drafts on us with the direct, over-the-footlights engagement that Beale achieves. But that arguable inconsistency is a small price to pay for the warmth and humanity that this great actor injects into the proceedings.

To 6 March (020-7369 1734)