Symbolism, foreshadowing, and irony are three important techniques used by William Shakespeare in his great tragedy Othello. In fact, one needn’t read very far into the play to discover at least two examples of each technique.
Symbolism, for example, appears when Iago tells Brabantio that Othello and Desdemona are “making the beast with two backs” (1.1.113). Rather than simply stating plainly that Othello and Desdemona are having sex, Iago uses vivid imagery and symbolism to suggest that Othello and Desdemona are behaving monstrously and unnaturally (at least from the perspective of Iago and Brabantio). They are, he suggests, acting like irrational beasts rather than like rational human beings – a claim that is ironic since no one will behave in a more monstrous way in this play than will Iago himself. Further symbolism can be seen when Brabantio calls out,
Give me a taper . . .
Light, I say, light! (1.1.138,141)
Brabantio seeks literal light, but he also seeks symbolic enlightenment concerning the truth of the charges against Othello and his daughter. Ironically, the enlightenment he receives will darken his life and actually lead to his early death. The “light” he seeks here is part of a larger pattern of symbolism of light vs. darkness that runs throughout the play. (Later, Othello will both literally and symbolically “put out the light” when he kills Desdemona [5.1.7]).
Foreshadowing also appears very early in the play, as when Brabantio, having discovered that Desdemona and Othello are indeed married, feels betrayed and warns Othello,
Look to her, Moor, if thou hast eyes to see:
She has deceived her father, and may thee. (1.3.287-88)
This warning, of course, foreshadows Othello’s later murderous suspicion that Desdemona has indeed been unfaithful to him. Ironically, however, Othello does not really use his “eyes to see” Desdomona as she truly is (loyal and faithful) but rather is deceived by Iago, not by Desdemona. Further ironic foreshadowing appears when Iago tells Roderigo that human beings “have reason to cool our raging motions” (1.3.325) – a statement that foreshadows Othello’s “raging motions” as well as his later failure to use his reason.
Meanwhile, much of what Iago says throughout the play exhibits irony, as in the words just quoted. Iago himself is full of “raging motions” (particularly in his vindictiveness toward Othello), so it is ironic that he should counsel anyone else about giving in to passion. Moreover, Iago uses “reason” only in the most debased and corrupted senses of the word. Instead of using reason to “cool” rage, Iago uses reason to promote rage in himself and others, whom he thereby manipulates. This is why the term “Honest Iago” (1.3.289) – which is used repeatedly throughout the play – is one of the most ironic terms in all of Shakespeare.