Possibly the most heinous villain in Shakespeare, Iago is fascinating for his most terrible characteristic: his utter lack of convincing motivation for his actions.
Iago's role in the play
Though deeply unpleasant, Iago must have considerable intellect in his ability to devise and deploy such a plan and to convince the other characters of various deceptions along the way.
Iago’s character is, as yet, unpunished at the end of the play. His fate is left in Cassio’s hands. It has to be believed that he will be punished but it is possibly left open for the audience to wonder whether he will attempt to get away with his evil plans by concocting some other deception or violent act.
Unlike the other characters in the plot whose personalities are transformed by the action (Most notably Othello, who goes from being a strong soldier to an insecure jealous murderer) Iago’s character is unchanged by the action of the play, he continues to be cruel and unrepentant.
In the first scene, he claims to be angry at Othello for having passed him over for the position of lieutenant (I.i. 7–32). At the end of Act I, scene iii, Iago says he thinks Othello may have slept with his wife, Emilia: “It is thought abroad that ’twixt my sheets / He has done my office” (I.iii.369–370). Iago mentions this suspicion again at the end of Act II, scene i, explaining that he lusts after Desdemona because he wants to get even with Othello “wife for wife” (II.i.286). None of these claims seems to adequately explain Iago’s deep hatred of Othello, and Iago’s lack of motivation—or his inability or unwillingness to express his true motivation—makes his actions all the more terrifying. He is willing to take revenge on anyone—Othello, Desdemona, Cassio, Roderigo, even Emilia—at the slightest provocation and enjoys the pain and damage he causes. This creates the key theme in the play: jealousy.
Iago is often funny, especially in his scenes with the foolish Roderigo, which serve as a showcase of Iago’s manipulative -abilities. He seems almost to wink at the audience as he revels in his own skill. As entertained spectators, we find ourselves on Iago’s side when he is with Roderigo, but the interactions between the two also reveal a streak of cowardice in Iago—a cowardice…