Jumpers, Lyttelton, National Theatre, London

Stoppard's verbal gymnastics made for Beale but less bounce left in 1970s philosophical concerns

The conventional complaint about Tom Stoppard used to be that his plays were all intellect and no heart: the turning point in his career supposedly being Arcadia, in 1993. It is an analysis that doesn't stand up to a viewing of Jumpers, which had its premiere in 1972. The play's central character is George Moore, a moral philosopher struggling under the burden of not being the George Moore who wrote Principia Ethica.

George is just about clinging on to his self-respect in the face of two-fold rejection - first by his beautiful, much younger wife, whom he has good reason to suspect is finding sexual solace with a colleague; and second by those same colleagues, who regard with amused contempt his old-fashioned beliefs in God and moral absolutes.

Although the play's theatrical razzle and fast-paced philosophical quibbling are impressive, what stays in the mind is the pathos of George's situation, and the faltering eloquence of his conviction of the reality of God. Nimbly intelligent, self-doubting, humorous - the part might as well have been written for Simon Russell Beale (and it is perhaps relevant that he played Hamlet not so long ago). His warm, naturalistic performance gives David Leveaux's production most of its shape and weight.

But while Leveaux stage-manages the physical and verbal gymnastics well enough, the play feels far less coherent or meaningful than I remembered. That is largely a matter of timing: George's anxieties about the decline of moral absolutes, of "good" and "bad", seem misplaced right now.

Having said that, in other respects the play remains surprisingly topical. Back in 1972 Stoppard was jabbing at political parties hiding arbitrary, authoritarian tendencies behind a rhetoric of radicalism and benevolence: he had the Archbishop of Canterbury turned into a political appointment, and the job given to the party agriculture spokesman. Last week's cabinet reshuffle was almost a replay.

The philosophy has worn less well. The kind of penny-plain, positivist approach to morality Stoppard resents has long been out of style. One of the conceits of the play is that Dottie, George's glamorous wife, gave up a career as a singer because the fact of men walking on the moon had destroyed all the spoony-moony-June romantic songs for her.

Now we know that the songs lasted better than the space programme, and her neurosis seems contrived. Essie Davis is excellent as Dottie, catching all her neediness and arbitrariness; if anything, she's too good in the musical numbers - hard to believe she's been away from the stage. Jonathan Hyde is urbanely efficient as Archie, George's nemesis and, probably, Dottie's lover.

Whatever the play's limitations, it is still a marvellous display of Stoppard's verbal ingenuity, with some beautifully contrived cross-purposes and neat gags - as when Archie tries to explain away a murdered professor in a plastic bag by suggesting that the man had crawled into the bag before shooting himself. "My God, why?" asks George. "Hard to say. He was always tidy."