Thus both in what he says and what he does there is the sense that he is at the very least evil, and perhaps even a fully satanic figure.
One part of Othello that gives credence to the idea of Iago as devil is that the character constantly seems to refer both the devil and hell as an excuse and even a catalyst for what he is doing. At the end of his final soliloquy he states that "hell and night will bring this monstrous birth, to the world's light". He relies upon his apparent link to hell, the devil and the dark powers that exist there to enable the "birth" of his plan to come to fruition. Iago believes that he is in some kind of relationship with the Devil; this is of course different from the idea that he is the Devil.
The fact that Iago apparently has little motivation for destroying most of the people around him is most powerfully argued by considering some of the reasons that he gives. He states that "I hate the Moor, and it is thought abroad that twixt my sheets he's done my office." (emphasis added). The and is perhaps the most important word here. It is an excuse for what he is doing rather than a reason. He hates the Moor because . . . he hates him. It is a self-defining emotion as far as Iago is concerned. Pure hatred for its own sake is regarded as the province of the satanic much as pure love is seen as that of the godly.
Like the Devil, Ia Like the Devil, Iago is far from stupid: in fact he is positively brilliant in his understanding of human nature. The manner in which he moves Othello from declaring his love for Desdemona to declaring that he will "chop her all into messes" is stunning because it is so believable. Iago knows precisely the weakest point of all those around him and exploits this for his own ends. So it actually is rather strange that Othello and Desdemona should be married due to their cultural, racial and age differences. Iago uses the vulnerability that Othello feels because of this strangeness to essentially drive the man to madness.
Throughout the play Iago is known as "honest Iago". He has apparently convinced everyone around him not only that he is not evil, but that he is positively good. Othello trusts him with his most intimate secrets. Cassio trusts him. Desdemona trusts him. Everyone in Venice appears to trust him, except for his wife that is. Emilia knows that the private Iago is very different from the public Iago. She is the first one to suspect that he is at the centre of all the lies that have been told while they are in Cyprus. In this way Iago is publicly very satanic but privately all too human. The reality of his public self is utterly unknown to those around him, almost to a supernatural level as if he has hypnotized those he comes into contact with.
Iago is casually evil at many points in the play, suggesting that evil is at the heart of his nature rather than being produced by volition. Thus he sets Cassio and Roderigo against one nother, not caring who kills who, and preferring if they both manage to kill one another in their fight. He kills his wife Emilia when it is an utterly futile action as the truth of what he has been doing has already been revealed. Desdemona is sent to her death in a similarly casual manner, as she is just a pawn in the game of chess that is playing against Othello. The callous disregard for life that this reveals is one of the