Iago is all things to all the characters in the play. He is; therefore, a good actor and lies well. He is able to manipulate those around him in order that they can carry out his evil work, especially Othello. Iago's ability to dishonor can be seen throughout the play and is demonstrated by roles he imitates. For example, he pretends to be Othello's friend, and becomes Cassio's adviser and Desdemona's last hope to regain her husband. He is none of these. He is a twister of words and actions. He deceives Roderigo and murders him; he has no regard for his wife and kills her, and betrays Cassio and Desdemona. All is because he has an all-consuming hate for Othello. He poisons Othello's mind, driving him to murder Desdemona. He never allows his feelings or passions, which are heavily suppressed, to interfere with his deadly purpose. Because of this, he is a repugnant person. However, it is not that Iago pushes aside his conscience to commit these acts, but that he lacks a conscience to begin with. Iago has a plan in mind to drive Othello insanely jealous by using manipulations and he does not care what happens to whom as long as his plan is working perfectly. .
Iago's entire scheme begins when Cassio is given the position he wanted. He is consumed with envy and plots to steal the position he feels he most justly deserves. Iago deceives, steals, and kills to gain that position. Iago reveals the real reason for his plotting against Othello, for the former believe that Othello slept with Emilia. These are the main causes of his hatred for Othello. A soliloquy that shows the hate Iago has for Othello is the following: .
"I hate the Moor,.
And it is thought abroad that "twixt my sheets.
He has done my office. I know not if't be true,.
But I, for mere suspicion in that kind,.
Will do as if for surety. He holds me well:.
The better shall my purpose work on him.
Cassio's a proper man. Let me see now,.