‘I am not what I am.’

Iago says this at the end of a long speech to Roderigo, and it is as close to a confession as he ever gets. His meaning is blunt: the Iago the world sees is not the real one. He follows Othello not from loyalty but to use him, as he admits in the same speech: ‘I follow him to serve my turn upon him.’

His image just before it does the heavy lifting. Showing your true feelings openly, Iago says, would be to ‘wear my heart upon my sleeve / For daws to peck at’. A daw is a jackdaw, a small crow. Honest feeling, in his view, is meat left out for scavengers.

There is also a biblical echo. God’s words to Moses in Exodus 3:14 are ‘I AM THAT I AM’. Iago turns that statement of absolute being into its opposite: a statement of absolute falseness.

This is the play’s opening scene, on a Venice street at night. Iago and Roderigo are on their way to wake Brabantio, Desdemona’s father, with the news that she has secretly married Othello. Iago has just explained his grievance: Othello passed him over for promotion and gave the lieutenancy to ‘one Michael Cassio, a Florentine’.

So before Othello has even appeared on stage, the audience knows exactly what Iago is. Everyone in the play keeps calling him honest (‘Honest Iago’, Othello says in Act 2). Only the audience has heard this line.

Identical words appear in Twelfth Night, Act 3 Scene 1. Viola, disguised as the young man Cesario, tells Olivia: ‘Then think you right: I am not what I am.’ Olivia has fallen in love with the disguise. Same words, opposite spirit: Viola’s deception is a costume she would happily take off. Iago’s goes all the way down.