Throughout Shakespeare's play, Othello, there are many themes interwoven to describe the author's perspective of the true nature of a man's soul. Three themes critical to the play are doubt versus trust, monstrous imagery and the fallible love of man.
One central theme of the play is the major contrast of doubt versus trust. For whatever reason, Othello's trust of Desdemona is too weak to resist Iago's accusations. As happens in many of Shakespeare's works, miscommunication and mistrust lead to "prepost'rous conclusions" (1. 3. 323).
Othello's heart tells him that Desdemona loves him; however the critical Iago can dismantle Othello's trust in his wife by planting seeds doubt through what appears to be rational proof. Having built Othello's curiosity about Cassio's supposed thoughts; Iago manipulates Othello into seeing a situation between Desdemona and Cassio that does not exist. Because Othello suspects that Iago is aware of more details than he is telling, he begins questioning Iago. "Why of thy thought?"(3. 3. 108), "What dost thou think?" (3. 3. 116). The superficially answered questions cause Othello to make demands for further clarification: "If thou dost love me, show me thy thought" (3. 3. 127-28), "give thy worst of thoughts the worst of words" (3. 3. 145-46), then "By heaven, I'll know thy thoughts!" (3. 3. 175). Due to Othello's equating of Iago's thoughts with factual knowledge, he is eager to mistrust Cassio and does not fully scrutinize the evidence. It is because he trusts Iago that he trusts the false "facts" and doubts the virtue of his wife, Desdemona.
In addition to inferring Desdemona's unfaithfulness to Othello, Iago alludes to Desdemona's duplicitous deception of her father, Brabantio -- she was able to "seel her father's eyes up close as oak"-when he reminds Othello that "She did deceive her father, marrying you" (3. 3. 224, 220). As Othello makes his final desperate attempt at trust by saying, "I