I had rather have this tongue cut from my mouth
Than it should do offence to Michael Cassio;
Yet, I persuade myself, to speak the truth
Shall nothing wrong him.

– William Shakespeare

Othello, Act 2, Scene 3. This is Iago’s response when Montano warns him to give a truthful account of the brawl and not one that favors Cassio. Lying comes so naturally to Iago. He pretends to be a loyal friend to Cassio, when in fact Iago orchestrated the fight in which Cassio stabbed Montano. His motivation: to discredit Cassio and replace him as Othello’s lieutenant.