Here's another observation regarding Othello: The character of Roderigo is an extraordinary one. He's the chap that is so far gone in infatuation with Desdemona, that he allows himself to be utterly manipulated by Iago. Iago lies to him about everything, spends his money and ultimately convinces him to murder Cassio. He doesn't succeed, though. He merely wounds Cassio, and so Iago, having to cover his tracks, walks up and kills him. At which point Roderigo sees the truth of his life for the first time, albeit very briefly. But the really remarkable thing about the character is that Shakespeare was able to control his telling of the story carefully enough, so as to make Iago the only person that interacts with him in the play. Roderigo literally allows another person to shape his entire view of the world. I forget who said that "all a poet can do is warn", but this character is the best illustration of that thought possible. One must consider one's sources.