If you were setting out to write a play you would at an early stage have to decide how to begin. That is to say, once your plot and characters had taken shape, you would have to determine how to introduce your audience to sufficient basic facts for them to appreciate the situation at the opening of the play and the relevance of fresh developments as they occurred. Moreover, you would aim to do this in a manner which was both economical and dramatic; and you would probably discover that your two aims were inconsistent. A bald exposition of the present position and past history of the more important characters would be economical in time but unsuited to the stage; whereas dramatic dialogue, of sufficient length to allow of the necessary knowledge being imparted indirectly to the audience, is apt to be verbose and disproportionately long.

In a modern play we should expect to find that any second- or thirdrate playwright has a slick enough technique to have resolved this discrepancy with a fair degree of success. But it was not always so; and this paper is largely concerned with the history of the tug-of-war between the two aims—the economical and concise exposition on the one hand and, on the other, the more leisurely and more properly dramatic build-up of the situation by natural explanatory dialogue and incidental allusions between characters on the stage.

For Aeschylus, the problem does not really arise in the form in which it faces his successors.