How does Othello’s final speech reestablish his greatness?
Having "done the state some service", Othello knows that the record of the events leading to Desdemona's death could be biased. Iago having been captured for the plot to murder Cassio, it is possible that Othello could be portrayed as a somewhat innocent victim of the plots of a madman. However, Othello begs against this. He wants the truth to be presented cleanly. Othello asserts that is was his own foolishness and jealousy that caused Desdemona's death, and not the actions of Iago, which should have had no effect on him. By repenting and by demanding the truth, Othello reestablishes his honorable nature, and therefore his greatness.