Outraged that a verdict has been passed against him, Alceste vows to live the rest of days in solitude, away from the society he has come to abhor. He tells Philinte that, in addition to the unfortunate verdict, his adversary has falsely attributed authorship of an obscene book to him. On top of all of this, Oronte has begun supporting the rumor. Philinte encourages Alceste to be reasonable, to challenge the verdict before committing to a life of solitude. Alceste objects, stating that he wants the verdict to stand has a glaring example of "the wickedness" of the times. He reveals his intention to test Célimène's love by asking her to withdraw from society with him.
Oronte demands that Célimène decide between him and Alceste. Agreeing with Oronte, Alceste makes the same demand. Both men agree to concede if Célimène chooses the other. Célimène calls their requests "inappropriate," not wanting to publicly offend the one she does not choose. She decides to let Éliante "be the judge" of her affections.
Éliante refuses to decide between Alceste and Oronte for Célimène, stating that Célimène has a responsibility to be open and honest to all present.
Acaste and Clitandre enter with a letter written by Célimène, demanding that she take responsibility for it. They read the letter, which insults each of Célimène's suitors and describes what she sees as their flaws. Decidedly tired of Célimène's insults, Acaste and Clitandre leave. Oronte follows them out, shocked that Célimène would insult him so. Alceste tells Arsinoé that she has no chance of gaining his love. She leaves, angry.
At this point, Alceste invites Célimène to retreat into solitude with him. She rejects the offer, but says that she will agree to marry him. Insulted, Alceste says that he wants nothing to do with her. Célimène leaves.
Alceste then tells Éliante that he cannot marry her, deeming himself "unworthy." She interrupts him, telling him not to worry, for she plans to devote herself to Philinte. Alceste again states his plan to live somewhere remote from society. As Philinte and Éliante exit, Philinte remarks that they must encourage Alceste to abandon his plan.