In Othello, Iago reveals the prevailing white male European Christian attitudes of the time: materialism, sexism, extreme male pride, fear of the black man stealing the white man's wife, and fear of Islam's expansion in Christendom.
Look at Iago's most revealing soliloquy:
Thus do I ever make my fool my purse:
For I mine own gain'd knowledge should profane,
If I would time expend with such a snipe.
But for my sport and profit. I hate the Moor:
And it is thought abroad, that 'twixt my sheets
He has done my office: I know not if't be true;
But I, for mere suspicion in that kind,
Will do as if for surety. He holds me well;
The better shall my purpose work on him.
Cassio's a proper man: let me see now:
To get his place and to plume up my will
In double knavery--How, how? Let's see:--
After some time, to abuse Othello's ear
That he is too familiar with his wife.
He hath a person and a smooth dispose
To be suspected, framed to make women false.
The Moor is of a free and open nature,
That thinks men honest that but seem to be so,
And will as tenderly be led by the nose
As asses are.
I have't. It is engender'd. Hell and night
Must bring this monstrous birth to the world's light.
Fear of black man sexually: "that 'twixt my sheets He has done my office: I know not if't be true; But I, for mere suspicion in that kind." He is racist and believes all black men to be animalistic sexually. His duty, then, is to protect the white woman.
Fear of Islam: "The Moor." So says one critic:
With Islam as a starting point, the rest of the play falls very nicely into the structure. Themes of West versus East are neatly upheld: Shakespeare’s Venice becomes a metaphor for the modern Western world, and the Turks easily fold into the ‘Us versus Them’ mentality of both 1603 and 2007. The intolerance of the play’s racial issues shines through clearly as well, the distrust of Moors in Shakespeare’s time paralleling well with America’s post-9/11 distrust of Muslims.