At the beginning of this act, we see that Alceste is putting his theories to the test; or as Philinte had said in the end of the last act, proving his "precious sincerity." This desire for absolute honesty on Alceste's part urges him to approach Célimène and openly tell her her faults.
The basis for Alceste's criticism of Célimène is that she has too many admirers and that she treats all people with the same degree of courtesy. She refuses to deny her presence to anyone and "gives any and everyone too easy access to" her heart. Browning's poem "My Last Duchess" aptly suggests the exact nature of Alceste's objections:
She had A heart — how shall I say? — too soon made glad,
Too easily impressed; she liked whate'er
She looked on, and her looks went everywhere.
In general, Alceste makes the unreasonable request of almost all lovers in wanting the lady to have no acquaintances other than himself.
Unlike Alceste, Célimène's arguments do not stem from any particular points of integrity. She argues like a coquette. First she asks if she can be blamed for her beauty. She is so naturally beautiful that men are automatically attracted to her. When Alceste spurns this, she then argues that these suitors can advance her interest in society. Finally, she is reduced to illogical but witty rebuttals against Alceste's objections. Isn't it better for her to have many suitors than to bestow her affections on one particular person. Finally, she complains that if he is so jealous then he really can't be in love with her.
