What is "political theatre"? Usually it means contemporary plays ranging from the journalistic through the "commitment" play (now not so fashionable) to the ultra-pseudy and obscure. Why are they always so awful? So jejune? Perhaps because it is hard to take seriously pronouncements from those who have never known war, violent death at close hand, extreme deprivation, or even life on the streets.
It can seem impertinent for the privileged to claim that they assert on behalf of those whom they neither know nor seek to know. There is something improper about the well-heeled seeking to represent the disadvantaged; it is an unacceptable invasion of territory. And to write of horrors within living memory, if you are not to sicken, you have to be a paid-up member. Your name must be Pasternak, Havel, Mandela, Solzhenitsyn. Otherwise you are a scavenger. Fashionable faux-Marxism, the radical chic of the 1970s, was disgusting; of the trashing of the Comédie Française in 1968, the best one could feel was how fortunate the young were to be able to play at revolution and not know the vicious shock of the real thing.
We live in an infantilised world for much of the time - cushioned by prosperity, only occasionally awakened, as recently by Iraq, into the difficult choices of maturity. Which is not to say that there is never time for direct political drama. In times of incitement, on the edge of violent civic change, there is a demand for the shout. Even here, direct action is usually more relevant than play-acting, however well-intentioned. Still, voices are insistent to be heard when despotic regimes crack, when political drama can be more than the preaching to the converted of middle-class theatre.
But politics belong on the platform, in the committee room, on the march. If you believe in it, do it. Contribute, directly, as a citizen. Support and improve structure directly if you're serious. And leave drama to the really dangerous world - the world of the imagination.
There is such a necessity for the expansion of imagination. As the Bishop of Durham says, we are all becoming cyphers and functions. Why is so much modern "serious" drama so impoverished, facile, inauthentic and out of touch with the lives of most people? Is it paucity of input - people being exposed to the same stimuli, looking at and listening to machinery instead of one another? Surely the theatre has something to contribute, as antidote if nothing else. So why does the work disappoint? Why do so many "full-length" plays run short, or lack a second act? Many offer us two sequential one-act plays - the goods laid out on the stall, intentions signalled - and that's it.
Drama is not, as we are often reminded, in the business of offering solutions. But we have, after doing our own day's work, travelled to the theatre and paid to be presented with the puzzle, and we rarely get it. Is this due to commercialism? We certainly don't live in idealistic times - the days of directors such as George Devine (who first staged Look Back in Anger ) are long gone. Careerism rules. Dramatists, in order to be heard, must court and placate directors, who hold the power - and who, being human, have their own scenarios and careers to nurture. Theatre, today, can be the stepping stone to more lucrative (if cheesier) television, and, with luck and graft, to the wider shores of film. These are the days of the business-artist. There is the compulsion to achieve high-profile success - now. It is pagan, anti-art and destructive.
So what should we be doing? Where does the educated, privileged artist put himself or herself in relation to the political? After all, we live in a postimperialist world, at least in the west. We live by the law of contract, and it is an equitable notion. Money talks. The hallowed world of finance was invaded by young, Porsche-driving spivs in the 1980s because they could do business. If there is to be political theatre, how should it be? Ibsenesque - the uncovering of social scandal? That belongs to direct action. Possibly, just possibly, there could be a place for the artistic imagination. Sane suggestions. Dreams of possibility embodied in drama. Invitations. Ways to go.
But here we have it. Drama begins where politics and the civic and direct involvement leave off. It inhabits a different territory. And we live in a desert; some mad fashion even decreed that kids should be given books about the world they know. Know what? The windy corridors of highrises? Urban living with no trees, gardens, animals, places to play in? Knowing cannabis weed better than chickweed? Cramped, fore and aft, by "political correctness"? If ever there was a need for books and plays and pictures of other worlds, there is now. It's hardly surprising that science fiction becomes more bizarre and violent. "Turn the hymns into pop songs," the thinking goes, "then they'll come through the door." Wrong. That is simply reductive, punitive deprivation.
What is so wonderful about live theatre is just that: it is live. In the moment. And you can do anything. Peter Shaffer had Robert Stephens climb the Andes in The Royal Hunt of the Sun . Historically, you need look no further than Shakespeare.
And the irony is, all theatre is political in a profound way. Why? Because it is subversive. It can, without resort to the vote or the gun, alter climate, change opinion, laugh prejudice out the door, soften hearts, awaken perception. Of course it can, because humans learn not by precept (the exhortations of so much political theatre) but by imprinting. Yell at a child to be quiet and you are teaching him to yell.
Drama influences. Not frontally, but subtly, through the stratagems of entertainment, through popular engagement. Think of Alan Ayckbourn and Joan Littlewood - there was bite enough in her work, but it was always subordinate to performance. She celebrated the moment, that unique quality of live theatre. If you want that nowadays, watch live football. Stand among 50,000 people and experience excitement, awe and despair - and, if Luis Figo is playing, ecstasy.
In the end, drama is, as Laurence Olivier said, "an affair of the heart". It is to do with insight, at warp speed; it cuts to the quick. And it is - can be, should be - very potent. As René Descartes wrote: "Feeling is thinking." And needs all the help we can give it.
· Pam Gems's translation of Ibsen's The Lady From the Sea is at the Almeida, London N1, until June 28. Box office: 020-7359 4404.