A discussion board for Othello Act IV and V In act IV we witness Othello go from a round character to a mad incoherent character. He also displays great cruelty towards the innocent Desdemona. What are the signs of Othello madness? what lines express his mental disintegration. what cruel acts does he perform? Also, find two metaphorical lines that can be analyzed into tenor and vehicle. How do Othello and Iago differ in their use of metaphor? Find a line with an unfamiliar word and look it up. How does understanding the word help you to understand the line?