If you read the entire Shakespeare canon, you become aware that Shakespeare was obsessed with female infidelity. This is dealt with not only in the plays, but also in the sonnets: "When my love swears that she is made of truth/I do believe her, though I know she lies" (Sonnet...
If you read the entire Shakespeare canon, you become aware that Shakespeare was obsessed with female infidelity. This is dealt with not only in the plays, but also in the sonnets: "When my love swears that she is made of truth/I do believe her, though I know she lies" (Sonnet 138). The image of the "horns" of the cuckold appears over and over again in his work.
Where this obsession came from, we can never really know, although scholars continue to speculate. Perhaps the "Dark Lady" of the sonnets was flagrantly unfaithful? In any case, in Othello, Shakespeare examines how jealousy and suspicion can poison a true love and the consequences of allowing an unfounded obsession to dominate action. Desdemona is a true innocent, and she suffers and dies because of Othello's fears, incited by the sublimely evil Iago.
Shakespeare clearly also wanted to continue to explore the concept of a simply evil man, something he had already dealt with to some degree in Richard III. However, in that play, he can't resist giving the gleefully villainous Richard some motivation (and one famous scene) so that the audience understands, to a degree, the reasons he is the way he is. Iago, on the other hand, spouts only very specious and flimsy reasons for his hatred of Othello. He was passed over for promotion. He "suspects" his wife of infidelity with the Moor, which is completely unbelievable. Ultimately, however, he's just bad and sadistically enjoys seeing the effects of his manipulations.
Then, although the "tragic flaw" theory is not in fashion at the moment, we can't help but see that the story becomes tragic, rather than melodrama, because Othello, a great man, is brought down by the crack in his armor, skillfully targeted by Iago.
Did Shakespeare also intend Othello to explore the concept of racism, in this case also internalized by Othello and causing his initial doubt to metastasize? The Elizabethans were not us, and we export our own views to their world at our peril—but, I believe, that as in The Merchant of Venice, the fact that we see these plays through a different prism merely illustrates why Shakespeare, as Ben Jonson wrote, "was not of an age, but for all time."