This is probing to the quick. Iago here turns the character of poor
Desdemona, as it were, inside out. It is certain that nothing but
the genius of Shakespeare could have preserved the entire interest
and delicacy of the part, and have even drawn an additional elegance
and dignity from the peculiar circumstances in which she is placed.
The habitual licentiousness of Iago's conversation is not to be
traced to the pleasure he takes in gross or lascivious images, but
to his desire of finding out the worst side of everything, and of
proving himself an over-match for appearances. He has none of 'the
milk of human kindness' in his composition. His imagination rejects
everything that has not a strong infusion of the most unpalatable
ingredients; his mind digests only poisons. Virtue or goodness or
whatever has the least 'relish of salvation in it' is, to his
depraved appetite, sickly and insipid: and he even resents the good
opinion entertained of his own integrity, as if it were an affront
cast on the masculine sense and spirit of his character. Thus at the
meeting between Othello and Desdemona, he exclaims, 'Oh, you are
well tuned now: but I'll set down the pegs that make this music, AS
HONEST AS I AM--his character of bonhommie not sitting at all easily
upon him. In the scenes where he tries to work Othello to his
purpose, he is proportionably guarded, insidious, dark, and
deliberate. We believe nothing ever came up to the profound
dissimulation and dexterous artifice of the well-known dialogue in
the third act, where he first enters upon the execution of his
design.

Iago. My noble lord.

Othello. What dost thou say, Iago?