Shakespeare
1
The scene sets up what is to come by giving the hint that just because something seems to be one way doesnt actually mean it isi.e., there is deception all around. This is laying the groundwork for the theme of deception: Iago is going to try to deceive Othello, and Othello is going to believe that he is deceived by Desdemona. The main evidence for this comes also in the beginning just before Othello and Desdemona set off: her father warns his new son-in-law that she has deceived me and may deceive thee.
2
One reason Iago gives for his scheming is that he has been passed over for a promotion that was given to someone elseto Cassio (who also becomes a target in Iagos plot). Iago also indicates that he hates the Moor, and this may be due to jealousy or even racism, although he never really goes too deeply into his motives. But the fact is that Othello is black and everyone else is white. The senators and Desdemonas own father view him as an outsider, though they welcome him as a warrior and defender of their city. I dont believe that Iagos malignity is necessarily motiveless; hatred for others can be a motive in and of itselfa desire simply to see everything that is good brought to ruin. He hates Othello like the devil hates God. He even says at one point, I am nothing if not critical. He lives to tear down and this is likely born of his own pride.
3
Othello is definitely more comfortable projecting a public image of a martial leader than he is being a private human being and husbandbecause he has more experience as a martial leader. He has no experience as a tender husband. His own marriage took him quite by surprise and it should be noted that in his own defense before the senators he tells how Desdemona basically pressed him to woo her, to tell her more stories of battle, and to make love to her. He understands battlebut he does not understand a private relationship: he learns only too late what it means to love not wisely but too well.
