How does Iago manipulate Othello?
At the beginning of the play, Iago divulges his vengeful and maliciously devious intention to manipulate and mislead Othello, his so-called friend. He tells Roderigo, "I follow him to serve my turn upon him." He means that he intends to mislead Othello by continuing to act as his trustworthy and obedient agent while, in fact, plotting against him.
Iago and Roderigo later successfully demonize Othello by convincing Brabantio that the general has abducted his beautiful daughter, Desdemona. Brabantio is driven to fury and decides to have Othello arrested for such an ignominy. At this point, Iago informs Roderigo that he has to leave and join Othello to further convince the general of his support. He tells Roderigo:
Yet, for necessity of present life,
I must show out a flag and sign of love,
Which is indeed but sign.
Iago's action in this regard epitomizes the nature of his strategy, which is to convince the general of his total commitment. In this way, Iago will not only retain Othello's trust but also deepen his leader's belief in him.
In scene 2, Iago tells Othello about his supposed anger at Brabantio for insulting the general and states that he could hardly bear listening to the senator's diatribe. To further confirm his loyalty, Iago later challenges Roderigo to a duel when the latter arrives in the company of Brabantio and others to accost Othello. Iago's attitude certainly convinces the general that his loyalty lies with him.
In act 2, scene 3, Iago and Roderigo's plot to have Cassio demoted is successful when Othello dismisses the young lieutenant from his service. Iago advises the distraught soldier to sequester Desdemona's help for reinstatement. It is Iago's sly intent to use Cassio to further his malicious plan by cleverly intimating to Othello that Cassio and Desdemona are having an affair.
Iago's first opportunity to implicate Cassio occurs in scene 3 of act 3 when, upon seeing Cassio trying to slip away surreptitiously after consulting Desdemona, he remarks: "Ha! I like not that." On hearing the comment, Othello wishes to know what he has said. Iago feigns ignorance.
When Othello asks whether he is correct in believing that he has just seen Cassio walking away from his wife, Iago replies that he cannot believe that it could have been Othello's ex-lieutenant who "would steal away so guilty-like, seeing you coming." Iago's careful diction is loaded with innuendo and suggests that Cassio has done something wrong. Othello is, of course, annoyed when Desdemona later tells him that she has been speaking to Cassio.
Iago has now cunningly baited Othello and proceeds to prey on the general's insecurities through further insinuation. He picks Othello's mind and provides him little bits of perfidious information by asking about Cassio's previous associations with Desdemona. Furthermore, he plays on the general's mind by being evasive. Iago drives Othello to suspicion by suggesting that there is something untoward about Cassio's relationship with Desdemona.
Receive it from me. I speak not yet of proof.
Look to your wife; observe her well with Cassio;
Wear your eye thus, not jealous nor secure:
He also preys on the general's ignorance about Venetian customs and hints that Venetian wives are wont to have secret adulterous affairs. By deliberately speaking about jealousy, Iago is, in fact, encouraging the general to be jealous.
At the end of act 3, scene 3, Iago tells Othello a blatant lie by mentioning an incident in which Cassio supposedly declared his passion for Desdemona. He states that he and Cassio had been sharing a bed when the soldier, while having a dream, attempted to mount him, mentioning Desdemona's name. Iago's coup de grace comes in the form of Desdemona's handkerchief which his wife, Emilia, gives to him. He plants it in Cassio's room and later uses it as proof of Desdemona and Cassio's iniquity. He tells the general that he has seen Cassio wipe his beard with it.
Othello is so overwhelmed that he vows to take revenge on both his wife and Cassio. Iago uses the opportunity to show his purportedly unquestionable allegiance and kneels. He swears to do whatever his general commands. Othello asks him to kill Cassio within three days while he takes care of Desdemona. He then names Iago his lieutenant.
In act 4, scene 1, in his final act of supreme manipulation, Iago manages to convince Othello that Cassio is speaking about Desdemona while the general eavesdrops on his and Cassio's conversation about Bianca, a prostitute who is in love with Cassio. Cassio speaks about Bianca disdainfully.
When Bianca arrives later, Othello is even more convinced when she expresses anger at Cassio for having dared to ask her to work on a handkerchief (Desdemona's) which he had given her. Othello has now had his "ocular proof." In his later conversation with Iago, he promises to chop Desdemona "into messes" or poison her, but he is persuaded by his lieutenant to strangle her in her bed.
Iago's manipulation culminates in the tragedy which sees Desdemona, Emilia, Roderigo, and Othello die.
Iago first manages to convince Othello that he is trustworthy. He shows his contempt for Othello when he says in Act I that he will lead Othello tenderly by the nose, "as asses are." We see that Iago's strategy is working by Act II, for Othello says of this most deceitful man: "Iago is most honest."
Because Iago has won Othello's trust, he is able to cast aspersions on others. He says in Act III, with complete cynicism, "men should be what they seem," through this implying that Cassio might be involved with Desdemona.
Iago works relentlessly throughout the play to destroy Othello's happiness. Sensing Othello's insecurity as a middle-aged black man married to a much younger woman, and projecting his own conviction that women are inherently unfaithful, he is able to use suggestion and innuendo to lead Othello to the false conclusion that Desdemona has betrayed him.
One way he does this is to contrive to have Othello overhear Cassio deriding his mistress, Bianca, while leading Othello to believe Cassio is talking of Desdemona. But, in actuality, it is not one incident, but a steady drip of Iago's falseness and innuendo that weaves a web of deceit around Othello.
Act 3 Scene 3 is known as “the seduction scene” (or “the manipulation scene”) because here Iago tricks Othello into believing that Desdemona is having a love affair with Cassio. Iago and Othello enter just before Cassio leaves, hearing the tail-end of the conversation. Iago says, “Ha! I like not that.,” which triggers a back and forth repartee between Iago and Othello that is like a dance: Iago drops a hint or uses a tone suggesting a relationship between Desdemona and Cassio, Othello asks what he means by the comment, Iago then demurs, only for Othello to demand more information, seemingly dragging it out of Iago while all the while it is Iago leading this dance. Iago’s skills at manipulation result in tremendous irony, for we the audience know what Iago is up to, but Othello seems like a dupe in not understanding what seems to us obvious manipulation.
Like a true evil genius, Iago plays upon Othello's own fears and reinforces those fears with lies and innuendo (hints). Iago manipulates the situation so that Cassio is in a position to ask Desdemona for aid. He then stands by Othello's side, professing concern for his friend, and questioning Desdemona's fidelity because she spoke for Cassio. By stealing Desdemona's handkerchief, Iago is able to plant it on Cassio and provide evidence for his lies. Finally, Iago arranges for Othello to overhear a conversation between himself and Cassio so that Othello believes he is hearing a confession. It all works. Othello gives in to his fears and his natural jealousy and he kills the woman he loves.
Most blame Iago for his duplicitious behavior, but some blame should also be laid upon Othello, who chose not to handle the situation with calm reason.