Examine scene 3 Act III so as to explain how Iago convinces Othello of Desdemona's infidelity

When Desdemona and Emilia leave, Othello immediately reaffirms his trust in Desdemona: " And when I love thee not, Chaos is come again ", of course Iago knows Othello is suspicious, proven by the very fact that he mentions that he might not love her. He gently moves on in his evil work as he asks Othello questions on his relationship and Cassio: " Did Michael Cassio, when you wooed my lady, know of your love?". After he asks this and other questions he doesn't tell Othello what his thoughts and arguments are so that it seems as if what he suspects is so big and terrible he first needs proof, and after he has it (the proof), the conclusion is so damaging he can not tell Othello, who of course is furious at what Iago's silence implies. Iago repeats what Othello says:

" Iago: Honest, my lord?

Othello: Ay, honest.

Iago: My lord, for aught I know.

Othello: what does thou think?

Iago: Think, my lord? "

to emphasise the importance of his thoughts and to anger Othello who has a short temper when people hide their thoughts so that he delays the answer and thus the contents of his thoughts. Othello himself sees this: " As if there were some monster in thy thought

Too hideous to be shown "

which shows that Iago's technique had worked, Othello is already too disturbed to think it is some story devised by Iago and expresses his doubts which were carefully implemented by Iago in his speech: " By heaven............thy thought " (line 106 to 117). Iago reinforces the 'I don't want to tell you what I think because I love you so much and think it will damage you' impression when he says: " My lord, you know I love you " which again blows Othello's anger over the top and provokes another long monologue which is exactly what Iago is looking to do. In his monologue he says that pauses and hesitations are for untrustworthy men merely tricks of habit, but for trustworthy men they are expressions of thoughts and feelings too powerful to be entirely suppressed:

" Therefore these stops of thine fright me the more;

For such things in a false disloyal knave

Are tricks of custom; but in a man that's just

They're close dilations, working from the heart,

That passion cannot rule. "

Thus proving himself quite clever but he has put Iago in the wrong category, that of honest men while he really belongs in the category of untrustworthy men who try to appear trustworthy.

Iago then goes on until line 165 to continue to delay the pouring out of the contents of his thoughts while making Othello more and more suspicious and angry until he says:

" O beware, my lord, of jealousy!

It is the green-eyed monster, which doth mock

The meat it feeds on."

He has said " jealousy " with all it implies, what Othello has been trying not to see in Iago's thoughts because of it's implications: an affair between Desdemona and Cassio has suddenly not only become a possibility but also a certainty. Iago has done this by telling Othello not to succumb to jealousy thus removing all guilt away from himself. He pushes the image in Othello's face by calling him a " cuckold " and to push Othello to confront the possibility of Desdemona's infidelity he again talks of jealousy, he says:

" But riches fineless is as poor as winter

To him that ever fears he shall be poor.

Good God the souls of all my tribe defend

From jealousy!"

He knows Othello is starting to feel " as poor as winter " and again his temper blows and his monologue that follows shows how he is not yet prepared to accept the full consequences of what Iago is implying, at least consciously for it is clear from his anger that subconsciously some part of him has accepted all Iago has said. This speech is his last attempt to fight off the conclusions set in his own mind by Iago as he desperately tries to make himself believe " Away at once with love or jealousy ". We see here how ruthless but especially smart Iago by the tremendous transformation he has brought along in Othello.

Othello is now sure of his wife's infidelity and Iago can now implement the idea even further into Othello by presenting more evidence to him. Othello, despite Iago's increasing openness and directness does not suspect any trickery. His own doubts are affirmed during his soliloquy which he starts with " Why did I marry? ", then Desdemona comes in and as she leaves he tells Iago how impossible it is that she is unfaithful and it becomes very interesting once again as Iago is forced to reinforce Othello's doubts starting line 373. Iago resorts to the old tactic of pretending to hate the pain he is causing except that here he is forced to pretend to be angry at Othello for doubting him and thinking him a liar and villain as he threatens to leave:

" O grace! O heaven forbid me!

Are you a man? Have you a soul or sense?

God b' wi' you! Take mine office. O wretched fool,

That lov'st to make thine honesty a vice! "

Of course Othello is not so sure of himself and of Desdemona's fidelity to let Iago go as he expresses his own doubts:

" I think my wife be honest, and think she is not;

I think thou are just, and think thou are not. "

He says he needs proof and Iago tries to tell him that the only real proof, to see them " topped ", is impossible to get. Of course, Iago the opportunist already has in mind the handkerchief Emilia gave him but he knows he must wait as Othello will not yet be convinced by that evidence. To set Othello up for the handkerchief he tells Othello of the words Cassio supposedly muttered in his sleep:

" Sweet Desdemona,

Let us be wary, let us hide our loves! "

then

" Cursed fate

That gave thee to the Moor "

Othello believes Iago because of his own trust in him, his belief that " men are what they seem to be " thus Iago isn't lying, and because of the realism of what Cassio supposedly said. Othello once again is sure of her infidelity, except even stronger than before: " I'll tear her all to pieces! " and Iago then goes on to talk of the handkerchief he saw Cassio wipe his beard with. Of course he knows that this handkerchief is one of Othello's dearest presents to Desdemona and since he has the handkerchief he knows that if Othello asks Desdemona for it she will not be able to produce it. This last piece of evidence has pushed away all doubt in Othello who can no longer control himself as he shouts: " O, blood, blood, blood! ". At this point Othello is mad and Iago's task is done.

Iago's skill which has produced the madness which we see in Othello at the end of the scene is truly frightening. If ever words could kill it is here in this scene as Iago slowly introduces piece by piece the idea that Desdemona is unfaithful in Othello's mind.