Mythos is the term used by Aristotle in his Poetics (c. 335 BCE) for the plot of an Athenian tragedy. It is the first of the six elements of tragedy that he gives.
“In Poetics 13 and 14, Aristotle turns from the discussion of the three separate parts of the plot to a consideration of the plot as a whole composed of these three parts”. In Poetics 13, Aristotle states his idea that the purpose of tragedy is the arousal of pity and fear. According to Belfiore, even though Aristotle uses one set of criteria for good plots in Poetics 13 and a different set in Poetics 14, “these two accounts are more consistent with one another than is often thought”. Aristotle defines plot in chapter 13 of Poetics as a variation of two different “change types” and three different “character types”. A tragic plot is a movement or change between the end points of good and bad fortune, because of that there are two possible kinds of change: change that begins in good fortune and ends in bad fortune, and change that begins in bad fortune and ends in good fortune. The three possible “character types” are the characters of “decent” people, people “outstanding in excellence and justice”; “evil people”; and the “in-between man”. Of the six logically possible outcomes, Aristotle lists only four. Aristotle contends in Poetics 13 that the most desirable plot involves ‘An in-between person who changes from good to bad fortune, due to hamartia, “error.” Additionally, Aristotle states that the plot in which ‘An evil person changes from bad to good fortune,’ is the most untragic of all because it is not philanthropic, pitiable, or fearful.’ Poetics 13 deals with good and bad combinations of character types and change. Conversely, Poetics 14 discusses good and bad combinations of a pathos with the knowledge or ignorance of the agent. “Ranked from worst to best, by Aristotle, these are the four logical possibilities of pathos:
1. A pathos is about to occur, with knowledge, but does not occur.
2. A pathos occurs, with knowledge.
3. A pathos occurs, in ignorance.
4. A pathos is about to occur, in ignorance, but does not occur”.
The emotional effect peculiar to the tragic action is therefore that of promoting the experience of feelings such as pity and terror, which constitute the ultimate end at which the representation of the mythos aims.