I think my wife be honest and think she is not;
I think that thou art just and think thou art not.
I’ll have some proof.

– William Shakespeare

Othello, Act 3, Scene 3. Othello’s mind is plunged into conflict. He doesn’t know what to believe or who to trust regarding his wife’s fidelity, or lack thereof. Iago, with his talent for manipulation, has Othello doubting that Desdemona has remained true. Othello, wanting to believe that she is loyal, tells Iago that he needs proof that she is untrustworthy.