"For where jealousy and selfish ambition exist, there is disorder and every evil thing" (The Bible, James 3:16). This "green-eyed monster" is the subconscious feeling of threat from the betterment of others. In Shakespeare's Othello, envy flows as the main crux of betrayal and leads to the demise of Othello. As iron is eaten away by rust, so the envious are consumed by their passions. .
Iago is the catalyst of all resentful acts, against Othello. It is Iago's selfish intentions, which the play evolves around. Iago's gluttony comes from Othello's decision of a "counter-caster" man for lieutenant and speculation of Othello sleeping with Emilia, Iago's wife: "I hate the Moor,/ And it is thought abroad that "twixt my sheets/ H'as done my office. I know not if't be true,/ But I, for mere suspicion in that kind,/ Will do, as if for surety" (Shakespeare, I.iii.381-382). Iago wants revenge for his own suspicion that Othello has gone to bed with Emilia. It is eating at his gut and he will not be satisfied "Till [he is] even'd with him, wife for wife, / Or failing so, yet that [he] put the Moor / At least into a jealousy so strong / That judgment [reason] cannot cure" (II.i.299-302). The phrase "even'd with him, wife for wife," seems to mean that he has some notion that he will have sex with Desdemona, but it is not the sex that is important. Othello must feel that same "poisonous jealousy" that Iago feels. Iago openly divulges his plan of destruction, which incorporates jealousy as the key factor. He intends to create a strong .
sense of greed in Othello by setting up the mirage of an affair between Desdemona and Cassio. Iago says, "[Cassio] takes [Desdemona ]by the palm: ay, well said, whisper:/ with as little a web as this/ will I ensnare as great a fly as/ Cassio" (II.i.325-229). Iago temps Othello by using false accusations of his wife's infidelities with Cassio. Iago also believes that by using Cassio in his plot against Othello, Othello will remove Cassio as lieutenant and give the honor to him for his loyalty.