Situational irony arises when an event occurs that is different from what is expected to happen. For instance, Portia and Nerissa offer rings to their fiancés, claiming that their love will endure as long as the rings are not given away. But in Act 4, the women themselves plot to get the rings back while disguised as the lawyer Balthazar and his clerk. Through dishonesty and persuasiveness, they manage to take the rings back from Bassanio and Gratiano. Soon after, in Act 5, they torment their fiancés by claiming that they slept with the men who took the rings, and they threaten to end their relationships. The audience hardly expects Portia and Nerissa—who gave the rings in the first place and demanded that their husbands keep them—to not only take back what they gave, but to continue their charade in such an elaborate, borderline cruel, fashion.
This trick also, ironically, defies the idyllic representation of love that Lorenzo and Jessica articulate at the start of the act. In reality, the marriages in this play thrive on deception and enduring power struggles. So while love is presented as a generously given gift, Portia and Nerissa make it clear by taking back the rings that, in any given situation, love can turn into something more punishing and unreliable.
One of the great ironies of Merchant is how the Christian characters—who base most of their actions in the Bible, and who we would therefore expect to support good faith and compassion—exhibit immense cruelty. This irony has led numerous modern critics to view the play as satirical, with the goal of inspiring audiences to reflect upon their own morality.
No one—not Antonio, Bassanio, or even Jessica—is capable of treating Shylock with kindness. Rather, they dehumanize him in order to distance themselves and to justify their own cruelty. No character manifests this hypocrisy more than Portia, who implores mercy from Shylock but who offers none in return. She and Antonio offer endless love to Bassanio, proving that they are not inherently heartless; they seem to heap abject hostility on Shylock by choice. Working in tandem in Act 4, Scene 1, Portia strips Shylock of his money and his home while Antonio forces him into the utmost degradation by making him convert to Christianity against his will.
Shylock says explicitly in Act 3, Scene 1, that his own spitefulness comes from watching the Christians and by enduring their wrath, but the Christians largely refuse to acknowledge what they have created and continued: a Christian world that dehumanizes and persecutes those outside of the ruling class.
