Discuss the thematic and dramatic purposes of the conversation between Bianca and Cassio in Act III, Scene iv, 166-200 in Shakespeare's play Othello.
In order to create and to build tension for the audience and character in the plot, Shakespeare places Cassio in a situation where he could have had the opportunity to introduce Bianca to Othello. This would have helped the Moor to see that Cassio was interested in someone else; but as fate would have it, Cassio tells Bianca that she must go on an errand for him (regarding the embroidery on the handkerchief that he found in his room) and not be hanging on his shoulder. At this point Cassio is on a soldier's quest to speak with his commanding officer and doesn't want to seem unprofessional. He even says to Bianca that she must leave because he doesn't want Othello, "To have him see me womaned" (189). For a brief minute, the audience might have a flame of hope that a peaceful and honest resolution could be made to the mischief Iago creates, but it is quickly doused. Each measure of hope that is dashed helps to build up to the climax of the story because of the many opportunities that could have saved the tragic end from happening (which is quite a familiar human quality to which each audience member can relate).