Another weakness of Othello is his lack of trust in his wife. He tries to persuade himself that Desdemona is faithful by saying, " For she had eyes and chose me. No, Iago/ I"ll see before I doubt; " Othello stills allows Iago to deceive him, based on no accurate evidence, merely observation, " Look to your wife, observe her well with Cassio." This reflects Othello's weakness and shows that the jealousy that is sowed in him is stronger then his moral judgement, "yet that I put the Moor/ At least into a jealousy so strong/ That judgment cannot cure." This use of a soliloquy again is effective in informing the audience of Iago's intentions and creates hatred towards the character of Iago. If Othello had trusted his wife, even Iago's jealousy couldn't of caused the tragedy. .
A further aspect of Othello's lack of trust of his wife relates to the handkerchief that he gave his wife. The handkerchief symbolises Desdemona's love and when it is lost Othello believes that Desdemona gave the handkerchief to Cassio and thinks she is in love with Cassio (due to Iago's manipulation), "Fetch me the handkerchief. My mind misgives." This jealousy shows Othello's weakness in relation to his lack of trust in his innocent wife. This reveals that Iago's jealousy is not the only factor contributing to the tragedy of Othello, but also the weakness of characters.
Therefore, Shakespeare uses jealousy to effectively form his tragedy in the play. It can be said that Iago's jealousy alone is to blame for the tragedy as it is the driving force of all the chaos as a result of his manipulation and deception of characters in the play. On the other hand, it can be more strongly argued that Iago's jealousy alone wasn't enough, as other characters are responsible for their actions and allowed Iago to play with their thoughts and emotions. Shakespeare uses a number of dramatic techniques to communicate the issue of jealousy through things like: the use of soliloquy's, use of descriptive dialogue , emotive language and symbolism.