Tragedy
that form of drama which represents the sad or terrible phases of human life and character. In order that a dramatic composition may deserve the name of tragedy, certain requirements are necessary. In form, the production must be poetical; in subject it must present events of weight and importance. The style must be lofty and finished; the movement stately, the diction grave and dignified. There should be unity of action, and the outcome, or catastrophe, as it is usually called, must be disastrous. Unity of action requires that every incident, however trifling, must be shown to be a part of the cause of the final catastrophe, or a part of the catastrophe itself.
Volume V · Aiton’s Encyclopedia