Wear your heart on your sleeve Introduction
I'm Iago. I hate Othello and I love plotting against him and his little wife, Desdemona. And you know what I think?
It is as sure as you are Roderigo,
Were I the Moor, I would not be Iago:
In following him, I follow but myself;
Heaven is my judge, not I for love and duty,
But seeming so, for my peculiar end:
For when my outward action doth demonstrate
The native act and figure of my heart
In compliment extern, 'tis not long after
But I will wear my heart upon my sleeve
For daws to peck at: I am not what I am. (1.1.56-66)
Who Said It and Where
Iago is one of the most notorious and mysterious villains of all time. He spends all of his time plotting against Othello and Desdemona, eventually convincing Othello that his wife's been cheating, despite the fact that Desdemona has been completely faithful. Iago's capacity for cruelty seems limitless. What's worse, he seems to have no real motivation for his actions.
Most other Shakespearean characters do bad things in order to achieve a particular goal. Oftentimes the culprit is ambition, as in Macbeth, or revenge, as in Hamlet.The thing about Iago is we never really know for certain why it is that Iago wants to destroy Othello.
Sure, he gives us a bunch of random reasons for the incredible destruction he wreaks on the lives of the people he knows best. But none of them seem to add up. In this scene, he gives Roderigo one of his many reasons he hates Othello (the Moor): Othello chose Cassio for Lieutenant.
Iago is peeved that he's basically still an ancient (or ensign, meaning the lowly ranked guy who carries the flag of an army in war) instead of second-in-command to Othello. Iago complains that people gain advancement because they're smart and loved, instead of reasons of seniority. He's bitter. (That's the understatement of the year.)
Still, Iago promises he'll get his revenge: he'll pretend to love the Moor and do service to him, but he plans to betray this Moor the first chance he gets. Iago declares, "I am not what I am," which is a perfect introduction to this treacherous, lying jerk-o-saur.