Calculus, New End Theatre, London

It's not moonlighting boffins, but non-scientists such as Michael Frayn and Tom Stoppard who have shown how drama can convert scientific ideas into profoundly imaginative metaphors.

It's not moonlighting boffins, but non-scientists such as Michael Frayn and Tom Stoppard who have shown how drama can convert scientific ideas into profoundly imaginative metaphors. The irony is that Carl Djerassi, the celebrated chemist who invented the contraceptive pill, writes plays that are far less interested in exploring the mind-expanding content of science than they are in exposing the unedifying moral behaviour of scientists.

Like Oxygen, one of his earlier works, Djerassi's new piece, Calculus, homes in on a "priority struggle". This time the dispute is between Sir Isaac Newton and his German contemporary, Gottfried Leibniz, over which of them can justly take credit for the eponymous discovery. Peculiarly, these mighty opponents, each accusing the other of plagiarism, put in only brief appearances. Djerassi shows us the contest at two artful removes - as the subject of a play-within-a-play and (within that) from the harassed perspective of the members of the Royal Society Committee, convened in 1712 by its president (one Sir Isaac Newton) to pass judgement on the issue.

Presented with fruity relish in Andy Jordan's engaging, if unevenly acted production, Calculus has an elaborate theatrical frame. The proceedings unfold in the Drury Lane dressing-room of actor-manager Colley Cibber. The architect/ dramatist Sir John Vanbrugh (an unashamedly over-the-top David Gant) arrives bearing a new script. The critics denounced his last play for "debauching" the stage and he's determined to revenge himself on them with a drama that shows how "real scandal is of the mind".

His example is the obsessive competitiveness that spurred Newton to pack out his committee with beholden appointees and to expect them to pass off as their independent collective appraisal a report he had himself written. That's the shocking theme of the play-in-progress which starts to materialise around the two men as they read and it out.

Given that Vanbrugh's great success, The Relapse, had been achieved by jumping on the bandwagon of Cibber's hit Love's Last Shift, the pair could easily have been at loggerheads. Their spirit of artistic collaboration ("the theatre is large enough for both us") is meant to serve as a contrast to the vicious rivalries in science. But the switches between workshop discussions and excerpts from the projected play too often feel like a way for Djerassi to cram in even more historical facts while failing to write a genuinely sustained drama.

And whereas I can understand why revelations about the dodgy personality of, say, a psychoanalyst might prompt a closer inspection of his theories, I fail to grasp how Newton's defects as a human being cast a shadow over his science - or why, if they don't, we should be so exercised about them.

To 28 August (0870 033 2733)