In Act 3, scene 4, Macbeth causes chaos at a celebratory banquet at his castle when he suddenly starts to behave very oddly indeed. Everything starts quite normally. The guests are greeted and they all sit down ready for the meal. One man is absent: Macbeth's old friend, Banquo. The reason why he is absent is very simple - Macbeth has just had him murdered.
Where Banquo should be sitting at the banquet, Macbeth sees instead his ghost. Imagine his horror and his reaction, and remember that no one else at the feast can see this ghost. Lady Macbeth tries her best to cover up for her husband, but in the end, has to send the guests away in chaos. What can we learn from this key scene?
The first point is about order. The scene opens with Macbeth telling the guests:
'You know your own degrees, sit down.'
By 'degrees', he means their places in the social hierarchy. The guests would sit around the table in order of their social standing, with the most important lords sitting nearest the king. A banquet is in itself an occasion of formality and convention. These words heighten this sense of ceremony.
This sense of social order was even more important to the people of Shakespeare's time than it is today. There was a whole Chain of Being in society, with god at the top, then the king, then the lords, followed by men, women and animals at the very bottom. The banquet is designed to reinforce this sense of social hierarchy, but ends in disarray: