I find that in the course of the day when I'm writing, after three or four hours of intense work, I have a splitting headache, and I have to stop. Because the involvement, which is both creative and self-critical, is so intense that I've got to stop doing it.

A play is a parenthesis that contains all the material you think has to be contained for the action of the play. Where do you end that? Where the characters seem to come to a pause... where they seem to want to stop - rather like, I would think, the construction of a piece of music.

The characters' lives have gone on before the moment you chose to have the action of the play begin. And their lives are going to go on after you have lowered the final curtain on the play, unless you've killed them off.

In the thirties a whole school of criticism bogged down intellectually in those agitprop, social-realistic days. A play had to be progressive. A number of plays by playwrights who were thought very highly of then - they were very bad playwrights - were highly praised because their themes were intellectually and politically proper. This intellectual morass is very dangerous, it seems to me. A form of censorship.

If you examine the history of any playwright of the past twenty - five or thirty years - I'm not talking about the comedy boys, I'm talking about the more serious writers - it seems inevitable that almost every one has been encouraged until the critics feel that they have built them up beyond the point where they can control them; then it's time to knock them down again.

I think it's for the critics to decide whether or not their loathing of the play is based on something other than the play's merits or demerits. They must search their own souls, or whatever.

If the playwright is strong enough to hold on to reasonable objectivity in the face of either hostility or praise, he'll do his work the way he was going to anyway.