Measure For Measure. Royal Lyceum Theatre, Edinburgh

If virginity is indeed making a comeback, as sociologists tell us, then maybe Measure for Measure is due for a revival in schools and colleges. Shakespeare’s moral maze, at its centre a heroine with the choice of saving her brother’s life with her maidenhead, has lost much of its tension since the swinging Sixties and contemporary students have difficulty taking Isabella’s problem seriously.

This was never going to be a problem at the Royal Lyceum, where the Nottingham Playhouse Company was directed by the fast-rising Stephane Braunshweig, head of the French Drama Centre before he was 30 and regularly touted as the philosopher who has turned to the stage. Shakespeare’s celebrated “problem play” is his first English language production and his first collaboration with a British theatre company.

It is easy to see why a moral philosopher should be attracted to the play. Shakespeare walks us through his maze of sexual morality, up the blind alleys and round the circles, showing us the many sides of vice and virtue until, like his Escalus, we no longer know which is which. Nowhere else in Shakespeare is the action so debated before it happens, or so analysed in retrospect.

Making this sexual metaphysics visually interesting is a challenge to any director. Braunshweig’s response is to design a gargantuan set of two towering walls, one revolving within the other, scaled by spiral staircases rising to the proscenium arch, and then to arbitrarily scatter the actors over it. Only occasionally do these walls and steps serve a dramatic purpose, and it is an added misfortune that the swift counter-thrust of Shakespeare’s scene-switching is deadened by the cumbersome and noisy carousel.

This eclectic set is matched by some dramatic and often arbitrary lighting and costumes chosen for the most superficial of reasons. What seems to be indifference or carelessness mars the edges of the play, and for the subtlety of interpretation the audience had to look to the central trio.

At its apex was Lise Stevenson, making a personal triumph of the difficult role of Isabella. Always one of the less likeable of Shakespeare’s heroines, her priggishness and prudery often alienate an audience. But here we have a journey of Isabella’s soul, from the shy, naive, zealous fundamentalist to the sadder and wiser woman who at the end studies her restored brother as though he were a statue and disdains the fatuous proposal of the Duke as though it were unheard.

There is truth too in Jim Hooper’s Duke. Explicitly, he is the arch-contriver, the puppet-master of the drama, universally admired and respected. But the text says often enough that he bears responsibility for the moral decay of the city, and Hooper brilliantly reflects, in his louche behaviour as a monk, the faults that forfeited law and order in Vienna.

In Angelo, the third of the trio, the director’s search for truth almost leads him to confrontation with the plot. The story demands that this stern judge and supposed hypocrite should be triumphantly exposed. But Paul Brennen’s Angelo is no black-hearted villain, but a young man unused and unready for high office. Out of touch with his own emotions, he is almost as much a victim of his own lust as he would make Isabella.

By this sacrifice of plot for character, Braunshweig wilfully discards Shakespeare’s stagecraft, which here is to pose a fundamental and complex moral dilemma for European Christendom, and then (literally) get out of jail with some fantasy plotting and standard villain-bashing.

Instead, the director has one more trick up his sleeve: Claudio’s last appearance is as nature rather than Shakespeare intended, like a Greek god in a machine, without a figleaf of philosophy about him. From then on, the text can go for nothing.

Until August 26. For details of a workshop at the Lyceum on August 20, 2-5pm ring the Festival Education Department, tel: 0131 473 2001