Great Dunsinane he strongly fortifies:
Some say he’s mad; others that lesser hate him
Do call it valiant fury: but, for certain,
He cannot buckle his distemper’d cause
Within the belt of rule.
– William Shakespeare
Macbeth, Act 5, Scene 2. The Scottish nobles who are marching against Macbeth discuss his mental state. Some people say Macbeth is mad, while others call it noble fury, Caithness says. Using metaphorical comparisons of sickness and clothing, Caithness claims that Macbeth is so out of control that he cannot keep a curb on his sick behavior.