Furthermore, Othello’s failure to trust Cassio gradually escalates and becomes Othello’s downfall. Iago’s hatred for Cassio begins to intensify in the opening scene when he states to Roderigo that Othello should have chosen him instead of Cassio as first lieutenant. Iago tells Roderigo, “I know my price, I am worth no worse a place” (I.i.11), and he feels that he has been cheated out of his role as leader. Thus, Iago sets out to create a plan whereby Othello will believe that Cassio is having an affair with Desdemona. As Iago hides Othello while inviting Cassio into a conversation about Bianca, Othello is persuaded by Iago that the words Cassio says are the description of affairs with Desdemona. Cassio aggravates Othello further by addressing Bianca (whom Othello believes is Desdemona) as a whore. As Othello is fed by Iago’s lies, his anger towards Cassio increases and his lust for revenge intensifies. Othello states, “Now he tells how she plucked him to my/chamber… O, I see that nose of yours, but not the dog I. shall throw it to!” (IV.i.139-141). Despite the fierce anger and antagonism Othello has toward Cassio, he does not question Cassio directly. Othello’s lack of trust in his first lieutenant gives Iago the chance to “…have him nine years a-killing” (IV.i.174). Othello develops a tendency to make rash decisions, and his poor judgement in the case of Cassio results in Cassio being injured.
Othello’s critical mistake in misjudging Desdemona’s infidelity results in Othello becoming a tragic figure. Othello claims to know Desdemona intimately. However, in the end, Othello’s sense of judgment is clouded by unwarranted jealousy. After Othello suffocates Desdemona, and by the time he realizes his actions, he describes himself as “of one that lov’d not wisely but too well” (V.ii.396). Othello kills his wife whom he earlier addresses as “…the sweetest innocent/That e’er did lift up eye” (V.ii.198) because he is impulsive and unwilling to listen to reason. Othello makes a mistake in that he refuses to answer his wife’s questions about his unusual behaviour. By the time Othello speaks honestly about what he saw and heard about Desdemona’s infidelity, he commits himself to kill his innocent and faithful wife. After his crime, he is told the truth about Iago’s lies and deceitful acts. Appalled by his behaviour, Othello states, “I kiss’d thee ere I kill’d thee: no way but this,/Killing myself, to die upon a kiss” (V.ii.354-355) and commits suicide. Othello’s jealousy becomes the catalyst for suicide which ends an otherwise loving relationship and industrious career.
To sum up, Othello’s jealous and impulsive nature influences his actions. Although Othello prides himself on being a stalwart fighter and of noble character, he nevertheless is morally weak, and knows little about true love. He accepts Iago’s words as truth, and discounts Emilia, Cassio, and his own wife, Desdemona. Othello’s pride stands in the way of reason, and he allows himself to be manipulated by a man whose goals are purely selfish. Othello’s downfall is, however, ultimately himself, for he could have chosen reflection/rational detachment over impulsivity and therefore averted tragedy.