Alceste, the misanthrope, explains to Philinte that he hates mankind because there is so much hypocrisy, deceit, and false flattery in the world that he can't find a man who will speak the truth openly. He asserts that all people should be completely frank and honest with one another. Philinte asks Alceste to be more tolerant because it is a part of human nature to flatter other people and to enjoy a certain amount of gossip. At this point, a fashionable man about town, Oronte, appears and asks Alceste to evaluate a poem he has just written. Alceste reads the poem and gives Oronte an honest answer — the poem is wretched and Oronte should give up trying to write poetry. Oronte, who has asked for an honest answer, is insulted when Alceste speaks frankly, and leaves in an indignant huff. Philinte points out to Alceste that his honesty has created an enemy, when a little innocent flattery would have won him a friend.
When Alceste meets Célimène, the woman he loves, he immediately begins to reproach her for her coquettish and flirtatious behavior. He dislikes the fact that she treats all people with the same charm and grace. She tells him that it is better to treat all people equally than for her to closet herself and heap all her favors on one person. In the midst of the argument, two fops, Acaste and Clitandre, arrive, followed by Philinte and Eliante, a woman of good reasonable sense. The fops immediately begin gossiping about various members of the court, and to Alceste's chagrin, Célimène joins in the gossip by castigating every person who is mentioned. Alceste cannot tolerate this, and tries to stop the performance. Shortly afterward, an officer arrives with a summons for Alceste. He is to appear before the court of the marshals because of his comments about Oronte's poem.
Later at Célimène's house, the two fops talk about her, but abruptly cease when she appears. Soon afterward a servant announces the arrival of Arsinoé a lady of society. When the fops leave, Arsinoé pretends to inform Célimène of the gossip being spread about her. In turn, Célimène tells Arsinoé what is being said about her. When Alceste arrives, Célimène excuses herself and leaves Arsinoé and Alceste together. Immediately, Arsinoé begins flattering Alceste and offers to show him proof that Célimène is false to him.
