The agony that Othello endures when he feels that he has lost Desdemona is expressed so eloquently and so passionately that it is difficult not to feel sympathy for Othello even when the reader knows that he is wrong. Two speeches are particularly poignant. The first occurs in Act 3 after Iago's words have begun to create suspicion and jealousy:
I had been happy if the general camp,
Pioners and all, had tasted her sweet body,
So I had nothing know. Oh, now forever
Farewell the tranquil mind! Farewell content!
Farewell the plumed troop and the big wars
That make ambition virtue! Oh farewell . . .
In this speech Othello's war and soldier references equate Desdemona's love to all that he feels is important in this world, to all that has defined him as a man. Everything that has made life seem worthwhile is lost to him now that he doubts Desdemona's love for him.
Later, Othello's anguish over the ocular proof Iago has provided of Desdemona's infidelity also reveal his deep emotions. He wavers between his anger toward Desdemona and his admiration for her in such lines as
Hang her! I do but say what she is, so delicate with her needle, an admirable musician--oh, she will sing the savageness out of a bear--of so high and plenteous wit and invention--
Here, we see Othello expressing within the same sentences his struggle between his love for Desdemona and his belief that she should be punished for her indiscretions.
And of course, Othello's unmitigated remorse for killing Desdemona and his refusal to rationalize his actions also create sympathy for this noble general:
Cold, cold, my girl!
Even like thy chastity. Oh, cursed slave!
Whip me, ye devils,
From the possession of this heavenly sight!
Blow me about in winds! Roast me in sulphur!
Wash me in steep-down gulfs of liquid fire!
O Desdemona! Dessdemona! Dead!
Oh! Oh! Oh!
The heaven and hell imagery here shows Othello's belief that his actions have damned him and that Desdemona's innocence will secure her a place in heaven. The short exclamatory lines indicate his extreme emotion, and the hyperboles show that he fully understands that he will suffer not only in this life but in the afterlife.
And finally, Othello's last speech, which places the blame only on himself for throwing "the dearest pearl away" is the last time that treasure imagery is used to describe Desdemona, and shows once more Othello's integrity for admitting his wrongdoing and his willingness to suffer the consequences for his actions.
In this way, pathos for Othello is established.