Despite Iago famously being accused by the poet Coleridge of "motiveless malignancy," in other words, of simply acting out of spite, we do get some idea of what is irking Iago.
Iago is clearly a very intelligent person. He can think ahead, plan, and organize. His great advantage over other people in the play is that he is always two or three steps ahead of them. He is a master strategist and sticks doggedly to his plans. We may hate how he uses this talent, but we must admit he has it, along with self-discipline.
Nevertheless, he is overlooked when it comes to promotions in the military. Othello is promoted over him, and Othello promotes Cassio over him. It would be annoying and painful for any person to have to constantly watch people you consider less talented get promoted just because, apparently, they have better interpersonal skills.
The depths of Iago's anger and hatred go far beyond what has been done to him by the characters we meet in the play, suggesting that he has repeatedly...
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