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.

– William Shakespeare

Othello, Act 1, Scene 1. Iago shows his jealousy of Othello and his position in Venetian society as general of the army. He reveals how two-faced he is, admitting that he will follow Othello, not out of love or loyalty, but simply to serve his own purpose. Incensed that Cassio has been promoted over him by Othello, Iago acts as Othello’s friend so that he can take advantage of him when the opportunity arises.