Peripeteia:
Peripeteia has been translated as ‘reversal of fortune’. A peripeteia occurs when a person sought to aim at a particular result, but the reverse of the result was produced. It brings about irony. In Marlowe’s Jew of Malta, Barabas was boiling oil in a cauldron to destroy his enemy, but he himself dropped in it and died. While in Shakespeare’s Macbeth, Macbeth heard the equivalent prophecy of the witches and sought to kill Banquo and all his enemies. But in reality, he got no peace and security, but only the damnation of his soul.
Anagnorisis:
Anagnorisis may be translated as ‘recognition or discovery’. Anagnorisis is a sudden realization of a grim truth. It is the point at which a principal character recognizes or discovers another character’s true identity or the true nature of their own circumstances. Aristotle defined anagnorisis as “a change from ignorance to knowledge, producing love or hate between the persons destined by the poet for good or bad fortune”. when Oedipus killed his father and married his mother in ignorance, and later learned the truth, or when Iphigeneia in Tauris realizes in time that the strangers she is to sacrifice are her brother and his friend, and refrains from sacrificing them Aristotle has spoken of six types of anagnorisis. The first type relates to the discovery by signs. The second type is the discovery, rather arbitrarily suggested by the dramatist. The third type of discovery is based upon memory. The fourth type of it is made through reasoning. The fifth type is based on false reasoning. And the last type is made by natural means.
Aristotle speaks of two types of plot in Poetics– simple and complex. A simple plot is one without peripeteia and anagnorisis; while a complex plot has peripeteia or anagnorisis or both.
Also read: Characteristics of tragic plot according to Aristotle