What opinions of Iago, before his exposure, are expressed by Othello, Desdemona, Cassio, and Lodovico?Is Othello the only one taken in by him? Does his own wife think him capable of villainy?
For the most part, characters have a very high opinion of Iago, reinforcing the idea that deception is, in fact, very powerful. Cassio turns to Iago for advice on how to get back into Othello's good graces, even though it's his trust of Iago that leads him to get drunk and lose his place at Othello's side. Roderigo gives Iago all his money despite the fact that the audience can tell Roderigo is being played. Even Lodovico trusts Iago. When he comes to visit Cyprus and sees Othello strike Desdemona, Lodovico turns to Iago for an explanation and then believes the explanation Iago provides. Desdemona is the only one to express doubt, and even then her doubts center on Iago's moral turpitude regarding women. In Act II, she calls him "slanderer" and "a most profane and liberal counsellor," but then later in Act IV, scene ii, she calls him "good Iago" and asks him, "What shall I do to win my lord again?" so obviously she has fallen for his deception as well. Iago's good (at least good at being bad).