As well as appealing to Othello’s emotions (pathos) and his reason (logos), Iago appeals to Othello’s respect for authority through the use of ethos. He does this by emphasizing his own authority and credibility to persuade Othello to believe that his wife is cheating on him. One example of this is when Iago talks about Venice and its people. Speaking in Act 3 Scene 3 about Desdemona, who is from Venice, Iago tells Othello:
I know our country disposition well.
In Venice they do let God see the pranks
They dare not show their husbands.
Here, Iago emphasizes his extensive experience of Venice to present himself as the authority on the matter. His knowledge of Venice in turn gives him insight into Desdemona’s true lascivious nature, or so he persuades Othello. By referring to it as “our country,” Iago uses the possessive “our” to subtly highlight the superiority of his link with Venice to Othello, who is not native to Venice. By doing so he emphasizes Othello’s comparative ignorance and plays on this insecurity, with Othello’s role as an outsider to Venice frequently referenced throughout the play. Indeed, Iago refers to him as a “wheeling stranger” to Roderigo in the play’s opening scene in Venice. By emphasizing his superior knowledge of Venice and its women, Iago thus gives Othello reason to respect his judgment.
Iago’s presentation of himself as honest and honorable is also an example of ethos, with his emphasis on his strong moral standing designed to get Othello to trust him. Iago does this through presenting himself as a reluctant messenger. In Act 3 Scene 3 he says to Othello:
I do not like the office,
But sith I am entered in this cause so far,
Pricked to't by foolish honesty and love
By saying he does not take any joy in telling Othello of his wife’s infidelity and that he is led only by “honesty and love,” Iago presents his motivations as true and honorable. By pretending that it pains him to be the messenger, Iago suggests that there is no self-interest in his actions, something which is designed to earn Othello’s respect. Iago thus uses ethos to appeal to Othello's sense of honor and earn his trust, thus making Othello more likely to believe his lies.