Teaching acting at the University of the Arts has given me a laboratory in which to examine the component parts of drama. The process of character construction is illuminated as an actor labors to transform himself into another person as defined by clues in a text.
Recently we examined mood and emotion. Specifically we searched for their impact upon character action. The distinction between the two qualities had already been clearly articulated in the work of renowned psycho-anthropologist Paul Ekman. He defines emotion as a short-lived response to a specific stimulus. He distinguishes this from mood, which is a protracted feeling that has no causation. (More likely mood is biological rather than experiential.)
Ekman spends many chapters in his book, Emotions Revealed (Holt Paperbacks), exploring the biological and sociological significance of this distinction. Writers, however, need only apply these two qualities of character as tools to analyze character action.
Since mood is sustained and unprovoked, we are able to select a mood for each character in every scene that predisposes them to the emotions requisite for advancing the action or plot. In other words, Othello is in an angry mood, then the machinations of Iago incite him to a murderous rage. Begin the play with the aging warrior in Hamlet’s deep sadness, and then he finds it difficult to be aroused from his lethargy to achieve the climatic action of the play.
Reducing the complex task of playcraft to a series of specific manipulations of the text is an important element of developing mastery. The interaction of mood and emotion is one of one hundred aspects of character that each of us know intuitively. Still, we are unlikely to apply this knowledge for best effect until the implications of each quality of character upon developing action are made conscious.