On one hand, Iago's racism and spite seal Othello's fate -- but on the other hand, there is a suggestion that his nature may predispose him to such violence and credulousness.
When realizing his folly, Othello, who told about his enslavement as a young man while wooing Desdemona, says he is enslaved once again, this time to the devil: "O cursed slave!/Whip me, ye devils,/From the possession of this heavenly sight!" (5.2). Othello also uses blackness to characterize evil, and goodness is portrayed as fair and light. But this does not necessarily support a racist reading of the play, the reading that Othello's true nature is coming forth. Rather, it shows that Othello is affected by racism, just as much as the other characters -- just like Brabantio who will accept a Moor as a guest, not a son-in-law, and just like Iago who can cunningly use Othello's race against the general he hates, even though his prejudices have more do to with personal vengeance than racism or a real disinterested critique of Othello's administrative style and capabilities. "Othello's 'Africanness' is crucial to his tragedy not because of what he is, innately or culturally, but because of how he is perceived, by others and by himself" (Berry 316). "Othello's blackness is not only a mark of his physical alienation but a symbol, to which every character in the play, himself included, must respond" (Berry 318).
However, one argument against this notion that the significance of Othello's blackness is due merely to its socially-constructed significance, not to its inherent evil as a signifier of the devil is Emilia's often unremitting racism, as seen after Desdemona's death when Emilia says "O, the more angel she, And you the blacker devil!" (5.2). Emilia, as manifest in her dialogue with Desdemona, is quite cynical and realistic, as opposed to her mistress' denial of the evils that men can do. She is often correct, and often racist in her instincts. This would seem to validate Othello's inherent brutality. Yet, on the other hand, Emilia's perspective on the world is also, always, fundamentally incomplete -- it is her blindness that results in her unwitting complicity in her husband's plot to trick Iago.
Goodness and racism are not incompatible in the play -- perhaps the most racist character is, ironically, Othello himself. Desdemona becomes a "black weed" when she is seen as unfaithful, and by implication he himself is a black and polluting influence upon her purity (Alderman 135). Killing Desdemona, in such a reading, is a form of internalizing social racism, not savageness. Marrying a white woman unmasks social racism in the society he has embraced, as manifest in Brabantio's rhetoric. This is what truly drives Othello to madness. Iago merely "legitimizes and intensifies" Brabantio's racism as a tool, but Othello really believes in it (Adelman 126).
And finally, and also quite tragically -- Desdemona's cultural differences with Othello unintentionally intensify the social forces of Venetian racism. "Othello's exoticism is deeply attractive to Desdemona-she loves him for the adventures he has passed-but it also contributes to her undoing. This sense of estrangement helps to explain what to many critics has seemed a paradox in Desdemona's behavior: the contrast between her independence and aggressiveness in Venice and her helplessness and passivity in Cyprus. She is secure among Venetians, insecure and uneasy in her marriage to a man she does not fully understand" (Berry 321). Her attempt to ignore potential differences between herself and Othello by acting in a friendly manner towards Cassio and assuming that everyone is 'the same' proves her undoing -- a foolish action, given that it was Othello's stories and exoticism that drew her to him in the first place. She ignores Othello's insecurities that are rooted in racism. Iago's fascination with sexual images and Othello's marriage bed, as he tries to portray Desdemona's infidelity underline these ugly, sexual assumptions about Moors to which Desdemona is subconsciously attracted, and which Othello and Desdemona's father, for different reasons, both fear.
Adelman, Janet. "Iago's alter ego: Race as projection in Othello." Shakespeare Quarterly. 48. 2
(Summer, 1997), pp. 125-144.
Bartels, Emily C. "Othello and Africa: Postcolonialism reconsidered." The William and Mary
Quarterly. 54. 1 (Jan., 1997), pp. 45-64
Berry, Edward. "Othello's alienation." Studies in English Literature, 1500-1900. 30. 2: