William Shakespeare began writing tragedies because he believed the plots used by other English writers were lacking artistic purpose and form. He used the fall of a notable person as the main focus of his tragedies (Tragic Hero) developed through the characterization of his pivotal characters correlated with a common theme or a controlling idea. His play Othello, written in approximately 1604 displays this style with the theme of human nature, its being of both good and evil within a person. He illustrates this through his two main characters, Othello and Iago. Paradoxically they are displayed as the exact opposites in the play, but they are exactly the same in that they both possess this ambivalence of good and evil.
There is no character in all of Shakespeare's plays so full of serpentine power and poison as Iago. He is envious of Michael Cassio and suspects that Othello has wronged his honor; but his malignancy is all out of proportion to even his alleged motives through which he shows his ambivalence of nature. His goodness of nature is not pure but simply good in appearence to the other characters. The reader sees the true evil of Iago and how he fools the other characters into believing he is an honorable man. His false displays begin with him and Roderego informing Brabantio of Desedemona's marriage to Othello, a Moor. The reader knows from the conversation between Iago and Roderego in Act I scene 1 that the two men are upset that Iago is not Lieutenant and Roderego cannot have Desedemona and they are acting out of Malice and retaliation. But, to Brabantio, their acts appear to be out of concern for the well being of Desedemona and respect for Brabantio.
The second instance in which the ambivalence is shown is after the Turkish fleet was destroyed by the storm in Act II, Iago acts acts like a friend to Cassio during the celebration and drinks with him. Knowing Cassio's low tolerance for wine, Iago easily gets him drunk while he is supposed to be on watch. He convinces Montano that this is Cassio's normal nightly routine while Roderego begins a fight with Cassio offstage which Montano is injured attempting to stop. When Cassio becomes sobered, he is unable to provide rationale for his actions and is hence dismissed with Othello's lines "Cassio, I love thee; but never more be officer of mine." The other characters believed that Iago had been a good samaritan, but he had really set up the lavish seen to relieve Cassio of his duty and line himself up for the position.
To exonerate himself from any suspicion on the part of Cassio, Iago once again pretends to befriend Cassio and offers his help in reinstating Cassio as Lieutenant, but he has alterior motives involving a conflict with Othello and Desedemona. He proceeds to play on Othello's jealousies hinting at an affair between Cassio and Desedemona while at the same time working with them to get Cassio reinstated thus making himself appear to be helpful and caring in the eyes of all three characters. Iago sets up encounters between Cassio and Desedemona that he will have secretly witnessed by Othello in which he will alter speech and actions to heighten the jealousies of Othello. All three unsuspecting characters progressively believe in the "purity" of Iago as he further plays on their naivete to suit his wants to be lieutenant and his deal with Roderego to free the hand of Desedemona for the likes of Roderego. He appears to succeed in the beginning, but as he tangles the characters in his lies, he gets himself tangled as well and the truth came about; Iago was thus put into custody and forced to await certain doom. Unfortunately for Iago his ambivalence of nature, which he thought suited him so well, left him victim of his own foul play.
A mean watchfulness or prying suspicion is the last thing Othello could be guilty of. He is of a free and noble nature, naturally trustful, with a kind of grand innocence, retaining some of his barbaric simplicity of soul in midst of the subtle and astute politicians of Venice. He is great in simple heroic actions, but unversed in the complex affairs of life, and a stranger to the malignant deceits of Iago, in which he also shows his ambivalence of nature. Othello despite his not so respected race as a Moor, was the well respected and talented general of Venice. Othello was also appointed the new governor of Cyprus upon his arrival for his outstanding leadership qualities and prowess on the field. His love was true to all those he was associated with. He was known to all he cherished as loyal and fair. For example, he accepted Michael Cassio back as a lieutenant despite the inappropriate behavior displayed previously because he respected Cassio and the opinions of Desedemona who pleaded on Cassio's behalf. His goodness cannot be theoretically be pinpointed in the play, but rather it is a constant display of valor and honor to all those around him. Unlike Iago his true person was always evident to all.
However, Othello showed evil qualities as well which were consequently the cause of his downfall as well as that of others around him. After being led to believe, without doubt, of an affair between Cassio and Desedemona he allowed his Temper and possessiveness take hold of his inhibitions and swore to the death of Desedemona and Cassio. Othello selfishly believed if Desedemona could not love him, no one should be able to love her, for no one could ever love her the way he did, hence the elimination of the problem. His jealousy was also a contributor to this conclusion; he correlated Cassio's possession of the handkerchief with Desedemona's insistance of Cassio's reinstatement as a definite sign of love and disallowed any other logical argument to sway his rash decisions. Unfortunately, Othello's narrow-minded actions resulted in the death of the one person whose love for him was true and unconditional, Desedemona as well as his own upon finding his pretenses for murder were false.
Othello is a tragedy that shows how ambivalence and manipulation are stronger in some cases than love and logic. Many good people died because of their ignorance to this fact. This theme is summed up in Othello's dying speech in which he declared himself as "one who lov'd not wisely but too well; of one not easily jealous, but being wrought, perplex'd in the extreme, of one whose hand, like the base indian, threw the pearl away."