Othello interrogates Emilia about Desdemona’s behavior, but Emilia insists that Desdemona has done nothing suspicious. Othello tells Emilia to summon Desdemona, implying while Emilia is gone that she is a “bawd,” or female pimp (IV.ii.21). When Emilia returns with Desdemona, Othello sends Emilia to guard the door. Alone with Desdemona, Othello weeps and proclaims that he could have borne any affliction other than the pollution of the “fountain” from which his future children are to flow (IV.ii.61). When Desdemona fervently denies being unfaithful, Othello sarcastically replies that he begs her pardon: he took her for the “cunning whore of Venice” who married Othello (IV.ii.93). Othello storms out of the room, and Emilia comes in to comfort her mistress. Desdemona tells Emilia to lay her wedding sheets on the bed for that night.

At Desdemona’s request, Emilia brings in Iago, and Desdemona tries to find out from him why Othello has been treating her like a whore. Emilia says to her husband that Othello must have been deceived by some villain, the same sort of villain who made Iago suspect Emilia of sleeping with Othello. Iago assures Desdemona that Othello is merely upset by some official business, and a trumpet flourish calls Emilia and Desdemona away to dinner with the Venetian emissaries.

Roderigo enters, furious that he is still frustrated in his love, and ready to make himself known in his suit to Desdemona so that she might return all of the jewels that Iago was supposed to have given her from him. Iago tells Roderigo that Cassio is being assigned to Othello’s place. Iago also lies, saying that Othello is being sent to Mauritania, in Africa, although he is really being sent back to Venice. He tells Roderigo that the only way to prevent Othello from taking Desdemona away to Africa with him would be to get rid of Cassio. He sets about persuading Roderigo that he is just the man for “knocking out [Cassio’s] brains” (IV.ii.229).

After dinner, Othello proposes to walk with Lodovico, and sends Desdemona to bed, telling her that he will be with her shortly and that she should dismiss Emilia. Desdemona seems aware of her imminent fate as she prepares for bed. She says that if she dies before Emilia, Emilia should use one of the wedding sheets for her shroud. As Emilia helps her mistress to undress, Desdemona sings a song, called “Willow,” about a woman whose love forsook her. She says she learned the song from her mother’s maid, Barbary, who died singing the song after she had been deserted by her lover. The song makes Desdemona think about adultery, and she asks Emilia whether she would cheat on her husband “for all the world” (IV.iii.62). Emilia says that she would not deceive her husband for jewels or rich clothes, but that the whole world is a huge prize and would outweigh the offense. This leads Emilia to speak about the fact that women have appetites for sex and infidelity just as men do, and that men who deceive their wives have only themselves to blame if their wives cheat on them. Desdemona replies that she prefers to answer bad deeds with good deeds rather than with more bad deeds. She readies herself for bed.

In Act IV, scene ii, Othello interrogates Emilia as if she were a witness to a crime. Her testimony would be strong evidence of Desdemona’s innocence, except that Othello dismisses it all as lies, because it does not accord with what he already believes. Just as there is no way for Othello to prove beyond any doubt that Desdemona has been unfaithful, no amount of evidence could now overturn Othello’s belief in her guilt. (In the final scene, Othello does abruptly decide that he has been deceived all along by Iago, but not because he is confronted by compelling proof.) Othello explains away any evidence in Desdemona’s favor, however strong, by imagining Emilia and Desdemona to be subtle and sophisticated liars.

When Othello has finished questioning Emilia, he interrogates Desdemona. She is still very much the articulate, generous wife she has been in earlier scenes, and she fervently denies Othello’s accusations. Even though he has no intention of believing her, he calls on her to swear that she is honest, as if all he wants is to see her damn herself with more lies. Moreover, he exaggerates her infidelities out of all proportion to reality or human possibility, comparing her copulation to the breeding of summer flies or foul toads. Having opened the floodgates of doubt, Othello seems to have expanded Desdemona’s infractions to make her the worst wife humanly conceivable. Perhaps any infidelity is as painful to him as a thousand infidelities, and his exaggerations only communicate the importance to him of her chastity. It is also possible that Othello’s belief that Desdemona has been unfaithful has robbed him of his only stable point of reference, so that he has no grip on reality to check his imagination.

Having had to preside over a state dinner right after being abused by her husband in Act IV, scene ii, Desdemona must be completely exhausted by the beginning of Act IV, scene iii. She submits without complaint to Othello’s order that she go to bed and dismiss Emilia. Despite Othello’s repeated offenses, Desdemona continues to love her husband. Alone with Desdemona, Emilia reflects that it would have been better if Desdemona had never seen Othello, but Desdemona rejects this idea, saying that Othello seems noble and graceful to her, even in his rebukes.

As Emilia undresses her, Desdemona suddenly remarks that Lodovico, who was onstage at the beginning of the scene, “is a proper man” (IV.iii.34). This remark suggests that Lodovico is attractive, all that a man should be, and it is somewhat puzzling, considering all that Desdemona has to think about at this moment. She may simply be unable to think any further about the inexplicable disaster that has befallen her marriage. Or, she may be mulling over the implications of Emilia’s idea: what would her life be like if she hadn’t married Othello? Having just been violently rebuked for infidelity by her husband, Desdemona now seems to think for the first time about what it would mean to be unfaithful. As if reading Desdemona’s thought, Emilia runs with the suggestion of Lodovico’s attractiveness, declaring that she knows a woman who would “walk barefoot to / Palestine for a touch of his nether lip” (IV.iii.36–37). Emilia’s comment serves as an invitation for Desdemona to speak more openly about the possibility of her infidelity.

When Desdemona tells the story behind the “Willow” song that she sings, she says that the name of her mother’s maid was “Barbary” (IV.iii.25), inadvertently echoing Iago’s description of Othello as a “Barbary horse” (I.i.113). The word refers to the countries along the north coast of Africa, and thus the name suggests an exotic, African element in Desdemona’s background, although the name “Barbary” was in use in Elizabethan England, so Barbary herself wasn’t necessarily African. The song itself is melancholy, and it portrays an attitude of fatalism regarding love, a resigned acceptance of misfortune that Desdemona seems to embrace. “Let nobody blame him, his scorn I approve,” she sings, before realizing that she has supplied the wrong words (IV.iii.50).

Desdemona’s attitude toward her chastity represents what Renaissance males wanted and expected of women, and it is certainly what Othello wants from his wife. She sees it as an absolute entity that is worth more to her than her life or ownership of the entire whole world. Emilia, on the other hand, suggests that the ideal of female chastity is overblown and exaggerated. Throughout the scene, Emilia seems to be trying to gently hint that instead of quietly suffering Othello’s abuse, Desdemona ought to look for happiness elsewhere. She argues that women are basically the same as men, and that the two sexes are unfaithful for the same reasons: affection for people other than their spouse, human weakness, and simple desire for enjoyment, or “sport” (IV.iii.95). Contrasted with Othello, who veers between seeing Desdemona as a monumentalized, ideal figure and as a whore with a thousand partners, Emilia’s words do not advocate infidelity so much as a desire for reasonable middle ground, a societal acknowledgment that women are human beings with needs and desires rather than virgins or whores.