THEATRE Marat / Sade Olivier, RNT, London

To join The Caucasian Chalk Circle in this first in-the-round season in the Olivier, the National Theatre has chosen another work that predominantly exists as a play-within-a-play. The heightened sense you get of being voyeurs when seated round a dramatic action in a self-aware ring should be of particular benefit to a staging of the Marat / Sade. Set in an asylum in 1808, it makes you privy to a performance, put on by the inmates, of a play about the historical events leading up to the assassination of Jean-Paul Marat.

There are disturbing overlaps between what is portrayed in this show - overseen and scripted by their fellow patient, the Marquis de Sade - and the inmates' own situation. "We want revolution - now!" they sing, as they re-enact a demonstration by the poor through Paris. Though the asylum authorities insist that the play is about remote historical events, a far cry from their own enlightened Napoleonic times, the past functions as a subversive mirror of the present. Playing starving revolutionaries, the inmates highlight their own status as prisoners demanding liberation. A production of Marat / Sade needs to convince you that the situation in the theatre could get dangerously out of hand. But Jeremy Sams's disappointing revival is an uncomfortable experience only in the sense of not being nearly uncomfortable enough.

One of the most distressing evenings of my reviewing life was up in Edinburgh at a Grassmarket project piece about young people in prison for serious crimes like rape and violent robbery. It was performed under the watchful eyes of warders and police, by a mix of real-life cases and actors. The combination of high-risk emotional volatility and disturbance on stage, and the surrounding images of armed restraint, was deeply upsetting and I remember thinking at the time that this must have been what it was like watching Peter Brook's legendary 1964 RSC staging of Marat / Sade.

Throughout the National Theatre version, the lunatics are all too clearly actors doing standard-issue mad turns, whereas in the Brook production, the performers had been encouraged in rehearsal to dig out the very particular mad person that lies in each individual. The results, we gather, were frighteningly authentic. "We were all convinced that we were going loony," remarked the then non-ministerial Glenda Jackson. In the Olivier, the one performer who convinces you that she is cut off unreachably in some confused private world of pain is Anastasia Hille, transfixing as the flounderingly narcoleptic Charlotte Corday.

The running debate in the piece between Marat and Sade ("On the one side he who thinks our lives/ can be improved with axes and knives/ Or the one who'd submerge his imagination/ seeking a personal annihilation") is conducted with clarity and vigour by David Calder - who brings a toying, sardonically triumphalist quality to Sade's role as ringmaster of this weird philosophical review, and a passionate conviction to his anti-idealism - and by a gravelly, Scots-accented Corin Redgrave, who indicates to just the right degree that this is not Marat but a paranoiac patient playing Marat as he sits, a mass of skin disease, in his bathtub.

The indignant interventions of Clifford Rose's asylum director kept reminding me of the headmaster's periodic pompous protests at the school play (another historical pageant with song and dance) in Alan Bennett's Forty Years On, the format of which is uncannily like that of the Marat/ Sade. It says something about the over-light tone of this production that you're free to make such a connection. In rep. Booking: 0171-928 2252