With the character of Iago, Othello presents the reader/viewer with an image of absolute malice. Whatever he may once have been, he appears, when we meet him, to be almost destitute of humanity, of sympathetic or social feeling. Passion, in Shakespeare's plays, is perfectly easy to recognise. What vestige of it, of passion unsatisfied or of passion gratified is visible in Iago? None: that is the very horror of him. He has less passion than an ordinary man, and yet he does these frightful things. Iago, as a representation of evil, has one major motivational factor that leads him to lie, cheat, and dominate other characters. This motivation is his obsessive, almost aesthetic delight in manipulation and destruction. Iago is not simply a man of action; he is an artist. His action is a plot, the intricate plot of a drama, and in the conception and execution of it he experiences the tension and the joy of artistic creation.
Iago is a character who essentially writes the play's main plot. He is the main driving force in this play, pushing Othello and everyone else towards their tragic end. A linguistic genius, Iago is a master of dialogue, dialectic, wit, insinuation, and persuasion. When trying to work Othello to his purpose, he is proportionally guarded, insidious, dark, and deliberate. The stops and breaks, the deep workings of treachery under the mask of love and honesty, the anxious watchfulness, the cool earnestness, and the hypocrisy, marked in every line weave a web of innuendo and suggestion to entrap and confuse Othello. Iago's insight into human nature; his ingenuity and address in working upon it; his quickness and versatility in dealing with sudden difficulties and unforeseen opportunities, have probably no parallel among dramatic characters. Though the most inveterate liar, Iago inspires all of the play's characters the trait that is most lethal to Othello: trust. Iago's mode of temptation, then, is to persuade Othello to regard himself with the eyes of Venice.