Alceste has waited for the others to leave before speaking his mind. But before he can say anything, Célimène admits that she has wronged him. She does not care for the anger of the others, but her betrayal of Alceste, she feels, is deserving of his hatred. Alceste, however, finds that he cannot hate her and is willing to forget her crime if she will consent to "flee from all mankind" and follow him into retirement. Célimène, however, says that "solitude has terrors for a soul of twenty." But if her hand in marriage would soothe Alceste she will suffer herself to be married.
Suddenly Alceste is disgusted by Célimène and tells her that now in her refusal to deny society, she has destroyed all love he previously had for her. He sends her away from his presence. Then he apologizes to Eliante, telling her that he has decided that he is not fit for marriage. Eliante explains that she has a promise from Philinte. He wishes them happiness and plans now to retire from the world and live in solitude, "where one is free to be an honest man." Philinte and Eliante hope that they can change his mind.
In the final analysis, Alceste offers Célimène a life of the misanthrope totally isolated from society. Since she has been presented as the epitome of all that society stands for, it is indeed an unreasonable request. As she points out, at twenty solitude is frightening for one who is accustomed to moving in the sphere of high society. In spite of the fact that she has just been trapped by the artificialities of that particular society, she does recognize that her position is as a member of society and that she cannot function as a misanthropic hermit.
Alceste does not realize that he has demanded the impossible from Célimène. He is egotistic enough to want her to conform completely to his personal specifications and live according to his rules. She is, of course, willing to modify some of her behavior and marry him, but she would indeed be unreasonable to deny completely her own personality simply to satisfy Alceste's exaggerated opinion of what constitutes proper conduct.
It is perhaps slightly difficult to believe in Alceste's sudden disapproval of Célimène. Simply because she won't conform to his ideas, he suddenly despises her and sends her away.
The comedy ends on a slight note of hope as Philinte and Eliante form an alliance which could offer some relief from the society presented so far in the play. The ending is not, however, the perfectly happy ending of the usual comedy.