t is the characteristic mental attitude of the
theatrical audience. If the mind is not stretching forward, the body
will soon weary of its immobility and constraint. Attention may be
called the momentary correlative of tension. When we are intent on what
is to come, we are attentive to what is there and then happening. The
term tension is sometimes applied, not to the mental state of the
audience, but to the relation of the characters on the stage. "A scene
of high tension" is primarily one in which the actors undergo a great
emotional strain. But this is, after all, only a means towards
heightening of the mental tension of the audience. In such a scene the
mind stretches forward, no longer to something vague and distant, but to
something instant and imminent.

In discussing what Freytag calls the _erregende Moment,_ we might have
defined it as the starting-point of the tension. A reasonable audience
will, if necessary, endure a certain amount of exposition, a certain
positing of character and circumstance, before the tension sets in; but
when it once has set in, the playwright must on no account suffer it to
relax until he deliberately resolves it just before the fall of the
curtain. There are, of course, minor rhythms of tension and resolution,
like the harmonic vibrations of a violin-string. That is implied when we
say that a play consists of a great crisis worked out through a series
of minor crises. But the main tension, once initiated, must never be
relaxed. If it is, the play is over, though the author may have omitted
to note the fact. Not infrequently, he begins a new play under the
impression that he is finishing the old one. That is what Shakespeare
did in _The Merchant of Venice._ The fifth act is an independent
afterpiece, though its independence is slightly disguised by the fact
that the _erregende Moment_ of the new play follows close upon the end
of the old one, with no interact between. A very exacting technical
criticism might accuse Ibsen of verging towards the same fault in _An
Enemy of the People._ There the tension is practically resolved with Dr.
Stockmann's ostracism at the end of the fourth act. At that point, if it
did not know that there was another act to come, an audience might go
home in perfect content. The fifth act is a sort of epilogue or sequel,
built out of the materials of the preceding drama, but not forming an
integral part of it. With a brief exposition to set forth the antecedent