what does othellos final speech reveal to us of his understanding of the tragedy that has overtaken him

Othello's grief comes to its fruition, as his reason and speech are finally fully restored. "Roast me in sulfur! Wash me in steep-down gulfs of molten fire!" Othello laments, the images of pain and torment reflecting the feelings which are coming over him (V.ii.278-279). He juxtaposes heaven and hell to explain his despair, and the virtue he knows again that Desdemona did possess. But though Othello has some sense again, he still wounds Iago; this act seems to be done as a distraction of his pain, and makes Othello's character seem even more deeply flawed.

Othello insists that he is an "honorable murderer", but he is driven to kill out of his own shortcomings (V.ii.293). Although his beautiful language and his remorse make him seem noble again, Othello still denies the character flaws that have led him to this end. Iago was definitely the catalyst for Desdemona's death and Othello's jealous rages; but the seeds of jealousy and suspicion were already inherent in Othello, and only had to be coaxed forth. It certainly makes the resolution of the play more neat to believe that Othello is returned to his nobility; but, since he still denies the deep wrong he has committed, and his own part in this dirty act, he cannot be fully redeemed or forgiven.