This is, without hyperbole, one of the most written upon character-based questions in Western literature. There have already been a couple good answers on here about Iago’s anger that he was passed up for promotion.
His line early in the play: “I hate the moor,” also suggests a possible undercurrent of racist motivation. (A quick side note: Othello is meant as a dark Turkish character, but in Shakespeare’s time might not necessarily have been represented as “black” the way the part is today. Though it also very likely could have been played in blackface. Either way, the racist undertones persist.) Iago also states that he suspects Othello might have slept with his wife Emilia, though how deeply he believes this suspicion is open to debate.
Iago’s true motivation is a difficult question to answer. One of the fascinating things about his character is that he gives so many different reasons to hate Othello (listed above), yet scholars still feel sure there must be some deeper,...
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