Aristotle, On Tragic Character AP English IV/1301 Review text in the Bedford,

Properties of Character The characters should be good—they will reveal their morals in speech and action It is possible to portray goodness in people of all classes (women, slaves…though Aristotle does state that they are an inferior class) The character should be appropriate—no female character should behave manly. Characters should be life-like, which is something different than making them good or appropriate Characters must be consistent—even if inconsistency is their consistency.

In his own words…. In the characters and in the plot-construction alike, one must strive for that which is either necessary or probable, so that whatever a character of any kind says or does may be the sort of thing such a character will inevitably say or do and the events of the plot may follow one after another either inevitably or with probability…..(Obviously, then, the denouement of the plot should arise from the plot itself and not be brought “from the machine” {deus ex machina}).