Aristotle, Poetics

[1454a] [1] So nobody does that, except occasionally, as, for instance, Haemon and Creon¹ in the Antigone. Next comes the doing of the deed. It is better to act in ignorance and discover afterwards. Our feelings are not outraged and the discovery is startling. Best of all is the last; in the Cresphontes,² for instance, Merope intends to kill her son and does not kill him but discovers; and in the Iphigeneia³ the case of the sister and brother; and in the Helle⁴ the son discovers just as he is on the point of giving up his mother.

So this is the reason, as was said above,⁵ why tragedies are about a few families. For in their experiments it was from no technical knowledge but purely by chance that they found out how to produce such an effect in their stories. So they are obliged to have recourse to those families in which such calamities befell.⁶

Now concerning the structure of the incidents and the proper character of the plots enough has been said.

Concerning "character" there are four points to aim at. The first and most important is that the character should be good. The play will show character if, as we said above,⁷ either the dialogue or the actions reveal some choice; and the character will be good, if the choice is good. [20] But this is relative to each class of people. Even a woman is "good" and so is a slave, although it may be said that a woman is an inferior thing and a slave beneath consideration.

The second point is that the characters should be appropriate. A character may be manly, but it is not appropriate for a woman to be manly or clever.

Thirdly, it should be "like."⁸ This is different from making the character good and from making it appropriate in the sense of the word as used above.

Fourthly, it should be consistent. Even if the original be inconsistent and offers such a character to the poet for representation, still he must be consistently inconsistent.

An example of unnecessary badness of character is Menelaos in the Orestes⁹; of character that is unfitting and inappropriate the lament of Odysseus in the Scylla¹⁰ and Melanippe's speech¹¹; of inconsistent character Iphigeneia in Aulis, for the suppliant Iphigeneia is not at all like her later character.

In character-drawing just as much as in the arrangement of the incidents one should always seek what is inevitable or probable, so as to make it inevitable or probable that such and such a person should say or do such and such; and inevitable or probable that one thing should follow another.

Clearly therefore the "denouement"¹² of each play should also be the result of the plot itself and not produced mechanically as in the Medea and the incident of the embarkation in the Iliad.