and it is actions such as these which, according to our hypothesis, tragedy represents; and, moreover, misfortune and good fortune are likely to turn upon such incidents.
Now since the discovery is somebody's discovery, in some scenes one character only is discovered to another, the identity of the other being obvious; but sometimes each must discover the other. Thus Iphigeneia was discovered to Orestes through the sending of the letter, but a separate discovery was needed to make him known to Iphigeneia. [Note]
We see then that two elements of the plot, reversal and discovery, turn upon these incidents. A third element is a calamity. Of these three elements we have already described reversal and discovery.
A calamity is a destructive or painful occurrence, such as a death on the stage, acute suffering and wounding and so on.
We have already [Note] spoken of the constituent parts to be used as ingredients of tragedy. The separable members into which it is quantitatively divided are these: Prologue, Episode, Exode, Choral Song,
the last being divided into Parode and Stasimon.
These are common to all tragedies; songs sung by actors on the stage and "commoi" are peculiar to certain plays.
A prologue is the whole of that part of a tragedy which precedes the entrance of the chorus.
An episode is the whole of that part of a tragedy which falls between whole choral songs.
An exode is the whole of that part of a tragedy which is not followed by a song of the chorus.
A parode is the whole of the first utterance of the chorus.
A stasimon is a choral song without anapaests or trochaics. [Note]
A commos is a song of lament shared by the chorus and the actors on the stage.
The constituent parts to be used as ingredients of tragedy have been described above; these are the separable members into which it is quantitatively divided. [Note]
Following upon what has been said above we should next state what ought to be aimed at and what avoided in the construction of a plot, and the means by which the object of tragedy may be achieved.
Since then the structure of the best tragedy should be not simple but complex [Note] and one that represents incidents arousing fear and pity—for that is peculiar to this form of art—it is obvious to begin with that one should not show worthy men passing from good fortune to bad. That does not arouse fear or pity but shocks our feelings.
Nor again wicked people passing from bad fortune to good. That is the most untragic of all, having none of the requisite qualities, since it does not satisfy our feelings [Note] or arouse pity or fear.