CONTAINER AND THING CONTAINED
USING "scene" in the sense of setting, or background, and "act" in the sense of action, one could say that "the scene contains the act." And using "agents" in the sense of actors, or acters, one could say that "the scene contains the agents."
It is a principle of drama that the nature of acts and agents should be consistent with the nature of the scene. And whereas comic and grotesque works may deliberately set these elements at odds with one another, audiences make allowance for such liberty, which reaffirms the same principle of consistency in its very violation.
The nature of the scene may be conveyed primarily by suggestions built into the lines of the verbal action itself, as with the imagery in the dialogue of Elizabethan drama and with the descriptive passages of novels; or it may be conveyed by non-linguistic properties, as with the materials of naturalistic stage-sets. In any case, examining first the relation between scene and act, all we need note here is the principle whereby the scene is a fit "container" for the act, expressing in fixed properties the same quality that the action expresses in terms of development.
Ibsen An Enemy of the People is a good instance of the scene-act ratio, since the correlations between scene and act are readily observable, beginning with the fact that this representative middle-class drama is enacted against a typical middle-class setting. Indeed, in this work written at the very height of Ibsen's realistic period, we can see how readily realism leads into symbolism. For the succession of scenes both realistically reflects the course of the action and symbolizes it.
The first act (we are now using the word "act" in the purely technical sense, to designate the major division of a play, a sense in which we could even reverse our formula and say that "the act contains its scenes") -- the first act takes place in Dr. Stockmann's sitting room, a