Iago’s reputation as a man of honesty and morality is a clear example of irony. Othello says Iago is “a man of honesty and trust,” Desdemona calls him “an honest fellow,” and Cassio says he “never knew a Florentine more kind and honest.” Iago, of course, ends up deceiving all three of these characters, making these remarks highly ironic. Indeed, part of the reason why Iago is able to manipulate these characters so easily is because he has so effectively cultivated this image of himself as trustworthy.
The frequency of such remarks on Iago’s honesty— “honest Iago” becomes somewhat of an epithet in the play—is also an example of hyperbole, with Iago’s reputation for honesty being exaggerated for dramatic effect. Iago himself also ironically refers to his own honest character as part of his method of deceive others. “I am an honest man,” he says; “I protest in the sincerity of love and honest kindness.” Likewise, Iago constantly criticizes the supposed dishonesty of others. To Roderigo he berates Othello’s “fantastical lies” while emphasizing Desdemona’s supposed deceitful nature to Othello. That Iago lies about how others lie is, of course, greatly ironic.
By stressing Iago’s honest reputation, Shakespeare highlights how deceiving appearances can be, with this idea being a crucial theme in the play. The audience’s awareness of Iago’s actual dishonest nature while the other characters sing his praises—with Iago telling the audience as much in his soliloquies—is an example of dramatic irony, ensuring the discord between appearance and reality is obvious to the audience.