Arts: Wanted: great performer. Actors need not apply

THEATRE: what is it? The definition is elusive and finally, perhaps, impossible. Theatre, you might say, is whatever takes place on a stage and is compelling. It is clear that plays as such are not the sine qua non of theatre.

Among the most extra-ordinary pieces of theatre I have ever seen was a lecture by AJP Taylor at the National Film Theatre on Hitler and film. The small, bespectacled figure, raffishly bow-tied, stood in the darkened auditorium, brilliantly illuminated in a single spot from which he never moved. His argument developed with buoyant lucidity, the lines of thought arching and converging in the dark, a sort of mental calisthenics, pentathlon of the intellect, until with perfect command, he finally brought us past the final tape, all the threads of his discourse firmly in his hand. A cheer went up as the spotlight faded. What is the common element here? Performance, of course, the drama of watching a lone person justify his or her moment in the spotlight, the stage as high-wire. Acting is not necessarily indispensable to theatre.

Take David Hare's Via Dolorosa, of which the writer gives the last performance tonight. Hare is reporting on an actual personal experience, his trip to Israel and Palestine, but also - and this is crucial - on himself. He offers himself up for examination: this is what happens to a person, he says, when he or she goes to Israel. This is what you find, and this is how it affects you. In the very act of his standing on a stage, without even so much a lectern, he offers himself up for examination, for contemplation. Unlike Taylor, Hare has not spent a lifetime of lecturing in public, honing his act. He is an intensely engaging speaker, witty, penetrating and often emotional, but he is not a pro in this area; much less has he acted in plays, like Harold Pinter and Wally Shawn. He walks with jagged self-consciousness on to the stage; his body jack-knifes as he speaks; words and phrases come accompanied with superfluous or sometimes contradictory gestures. He lacks the author's whorish skill of making it seem as if he was saying all this for the first time. It's definitely a text. Nor does he shape the material particularly well, paragraph by paragraph. It is possible to imagine the text better delivered.

All of this is beside the point. The point is that it's him telling us about what happened to him, and in that sense the event is similar to the experience of hearing a poet read his own verse. The sense of authenticity is somehow the greater for the lack of finesse in the delivery. The same is true of the characters whom he describes: Mike Yarwood he ain't, but you get a remarkably vivid impression of the tone, the personality, of these people and what he thinks about them.

What he has to say about Israel and Palestine is naturally of deep interest, acute and informative. What is perhaps unexpected is how moving it is. The Israeli experience becomes cumulatively heart-breaking, and Hare the performer seems to sag under the weight of it. He pauses, sits at a table, sips water. What he has witnessed seems to pass before his eyes. The powerlessness of passion, of intelligence, of kindness, all seems to bear him down. He wanders about the set, contemplates the impressive model of Jerusalem that rises up and hovers in the mid-air like a spaceship. He looks at these things, but he does not seem to see them. An actor would relate to the set, to his surroundings with a conscious effort of focus, but Hare is elsewhere, playing over his memories on a mental screen. When the show is over, he seems to see us for the first time, bows almost absent- mindedly and then walks all the way to the back of the stage, leaves, and then walks all the way back.

It is as haunting as anything by Beckett. The event has become a metaphor, and that is what the theatre must never fail to be.