Anagorisis and Peripeteia

Terms devised by Aristotle in his Poetics to describe the nature of events in a tragedy

Anagnorisis [Recognition/Discovery] is that moment in a plot or story, specifically in a tragedy, wherein the main character either recognizes or identifies his/her true nature, or recognizes the other character’s true identity, discovers the true nature of his situation, or that of the others, leading to the resolution of the story.

Up to that moment there has existed a state of Tragic Irony, a disharmony created when the tragic significance of a character’s speech or actions has already been revealed or is known to the audience but unknown to the character him or herself.
Aristotle discusses anagnorisis at length in his Poetics, defining it as “a change [that] occurs from ignorance to knowledge, creating love or hate between the individuals doomed by the poet for bad or good fortune.” Simply, it is a startling discovery, which brings a change from ignorance to knowledge.

Such is the discovery made by Oedipus in Oedipus Tyrranus when he learns from the messenger who he is. The messenger arrives from Corinth to tell Oedipus that his father, Polybus, is dead, and that the people of Corinth wish for Oedipus to be their new king, but he also reveals to Oedipus that Polybus and Meropé are not his real parents. A messenger enters, looking for Oedipus. He tells Jocasta that he has come from Corinth to tell Oedipus that his father, Polybus, is dead, and that Corinth wants Oedipus to come and rule there.

Peripeteia [Reversal of Fortune or Tragic Catastrophe]. Aristotle, in his Poetics, defines it as "a change by which the action veers round to its opposite, subject always to our rule of probability or necessity."

Aristotle considered that it was the mark of a great tragedy when Anagnorisis led to Peripeteia, subject to the general rule mentioned everywhere in the Poetics that all events in the drama had to be causally connected.

References

Philip F. Kennedy; Marilyn Lawrence (2009). Recognition: The Poetics of Narrative : Interdisciplinary Studies on Anagnorisis. Peter Lang. ISBN 978-1-4331-0256-1.

David Mikics (1 October 2008). A New Handbook of Literary Terms. Recognition: Yale University Press. pp. 257–. ISBN 0-300-13522-X.

Anagnorisis - Wikipedia

Peripeteia - Wikipedia

Amélie Rorty (1992). Essays on Aristotle's Poetics. Princeton University Press. pp. 197–. ISBN 0-691-01498-1.
A Simple View of "Peripeteia". Aristotle, "Poet". 1452 A. 22-29
O. J. Schrier
Mnemosyne
Fourth Series, Vol. 33, Fasc. 1/2 (1980), pp. 96-118
Published by: Brill
https://www.jstor.org/stable/4430932

"Anagnorisis" and "Peripeteia" in Comedy
Roger W. Herzel
Educational Theatre Journal
Vol. 26, No. 4 (Dec., 1974), pp. 495-505
Published by: The Johns Hopkins University Press
DOI: 10.2307/3206611
https://www.jstor.org/stable/3206611

The Reverse of Aristotle
F. L. Lucas
The Classical Review, Vol. 37, No. 5/6 (Aug. - Sep., 1923), pp. 98-104
https://www.jstor.org/stable/697284Selected text

Perseus Aristotle's Poetics -1452a

Perseus Aristotle's Poetics -1454a

Perseus Sophocles OT 950-