by
academic critics, on literary grounds; but it is surely more sane to
explain them on grounds of common sense, in the light of what we know of
the conditions of the Attic stage. Similarly, it would be easy to show how
Terence and Calderon, Shakespeare and Moliere, adapted the form of their
plays to the form of their theatres; but enough has already been said to
indicate the principle which underlies this particular phase of the theory
of the theatre. The successive changes in the physical aspect of the
English theatre during the last three centuries have all tended toward
greater naturalness, intimacy, and subtlety, in the drama itself and in the
physical aids to its presentment. This progress, with its constant
illustration of the interdependence of the drama and the stage, may most
conveniently be studied in historical review; and to such a review we shall
devote a special chapter, entitled _Stage Conventions in Modern Times_.

We may now observe that, in the third place, the essential nature of the
drama is affected greatly by the fact that it is destined to be set before
an audience. The dramatist must appeal at once to a heterogeneous multitude
of people; and the full effect of this condition will be investigated in a
special chapter on _The Psychology of Theatre Audiences_. In an important
sense, the audience is a party to the play, and collaborates with the
actors in the presentation. This fact, which remains often unappreciated by
academic critics, is familiar to everyone who has had any practical
association with the theatre. It is almost never possible, even for trained
dramatic critics, to tell from a final dress-rehearsal in an empty house
which scenes of a new play are fully effective and which are not; and the
reason why, in America, new plays are tried out on the road is not so much
to give the actors practice in their parts, as to determine, from the
effect of the piece upon provincial audiences, whether it is worthy of a
metropolitan presentation. The point is, as we shall notice in the next
chapter, that since a play is devised for a crowd it cannot finally be
judged by individuals.

The dependence of the dramatist upon his audience may be illustrated by the
history of many important plays, which, though effective in their own age,
have become ineffective for later generations, solely because they were
founded on certain general principles of conduct in which the world has
subsequently ceased to beli