Aristotle's Theory

Mimesis is the idea that the specific tragedy is universal. There is a chain reaction due to the tragedy which could affect anyone, purely because 'that is the way the world operates'. As a result of this, tragedy causes fear as well as pity in an audience, as they could be part of the chain reaction so the tragedy could affect them.

The Incentive Moment is the beginning of the play, which causes the chain reaction of events. It must be dependent on something within the play.

The Dénouement is the time between the incentive moment, where there is the pivotal incident, to the point in which the incident is resolved.

The plot must be complete while being self contained. It must have no outside input, or Deus Ex Machina. Each point of the story must move to the next point while being bound together internally.

A catastrophe is a moment which changes the plot. Simple plots only have a catastrophe, whereas complex plots (which are deemed better) have a change of intention and a moment of recognition or realisation connected to or the result of the catastrophe.