se to effect, are
equally clear. It is his fault if in the action of his drama anything is
left unaccounted for--not _motive_; though a dramatic _motif_ might not
always prove to be a sufficient explanation in real life. Accordingly,
every drama should represent in organic sequence the several stages of
which a complete action consists, and which are essential to it. This
law of completeness, therefore, lies at the foundation of all systems of
dramatic "construction."

Systems of construction based on this law of completeness.

Every action, if conceived of as complete, has its causes, growth,
height, consequences and close. There is no binding law to prescribe the
relative length or proportion at which these several stages in the
action should be treated in a drama; or to regulate the treatment of
such subsidiary actions as may be introduced in aid of the main plot, or
of such more or less directly connected "episodes" as may at the same
time advance and relieve its progress. But experience has necessarily
from time to time established certain rules of practice, and from the
adoption of particular systems of division for particular species of the
drama--such as that into five acts for a regular tragedy or comedy,
which Roman example has caused to be so largely followed--has naturally
resulted a certain uniformity of relation between the conduct of an
action and the outward sections of a play. Essentially, however, there
is no difference between the laws regulating the construction of a
Sophoclean or Shakespearian tragedy, a comedy of Moliere or Congreve,
and a well-built modern farce, because all exhibit an action complete in
itself.

Prologues and epilogues outside the action.

Parts of the action. Introduction or exposition.

The "introduction" or "exposition" forms an integral part of the action,
and is therefore to be distinguished from the "prologue" in the more
ordinary sense of the term, which like the "epilogue" (and the Greek
[Greek: parabasis]) stands outside the action, and is a mere address to
the public from author, presenter or actor occasioned by the play.
Prologue and epilogue are mere external, though at times effective,
adjuncts, and have, properly speaking, as little to do with the
construction of a play as the bill which announces it or the musical
prelude which disposes the mind for its reception. A special kind of
preface or argument is the "dumb-show," which in some old plays brief