Final answer:
Aristotle's term for a protagonist's sudden change of circumstance in a narrative is peripeteia, a reversal of fortune that is key to the plot of a tragedy and closely related to the concept of anagnorisis, or moment of recognition. These elements are crucial in the development of a tragic hero, whose downfall is due to a mix of personal flaws and unforeseen events, aiming to elicit catharsis in the audience.
Step-by-step explanation:
The term Aristotle used to describe the sudden change of circumstances affecting the protagonist, leading to a reversal of fortune, is called peripeteia. This occurs in tragedies when an event causes the protagonist's situation to change drastically, often contrary to what was originally intended. For example, in Sophocles' play Antigone, Creon experiences peripeteia when his decisions lead to the deaths of his son and wife, dramatically altering his life. Another key concept linked to peripeteia is anagnorisis, which refers to the critical moment of recognition or discovery, particularly of some truth about the protagonist's own identity or situation, as seen in the tragedy Oedipus Rex.
According to Aristotle's Poetics, a tragic hero is a character who possesses a mix of good qualities and a tragic flaw, or hamartia, that ultimately leads to their downfall. The character experiences peripeteia, and this dramatic turn in the plot is instrumental to bringing about the emotional catharsis in the audience through the elicitation of pity and fear. The interplay between peripeteia, anagnorisis, and the ultimate catharsis creates the powerful effect intended by a tragedy.