The incidents that take place at the opening of the play, at the same time as the change in the attitude of lago, are two, the courtship and marriage of Othello and Desdemona, and the promotion of Cassio to the position of lieutenant …show more content…
The dramatist has almost completely changed the point of view of the whole story, by inventing an entirely new, and perhaps loftier if not better, motive for his lago. On the other hand, he transformed the one he found in the story, and invented the character of Roderigo to bear that vulgar part. Then he invents a second motive for Iago, and makes him hate Othello also for his supposed relations with Emilia. By way of revenge for this offence, lago's first impulse is to try to corrupt Desdemona, and thus get even with Othello. But how little this was his intention is seen by the fact that he never seems to have seriously considered it. In place of this, however, he has an alternative that becomes his ruling motive, to put Othello into a jealousy of Cassio. This he thinks will serve to revenge himself on Othello for both offences at one blow:
And nothing can, or shall content my soul
Till I am even'd with him, wife, for wife.
Or failing so, yet that I put the Moor
At least into a jealousy so