1. Symbolism of Guilt and Corruption: After Duncan's murder, Macbeth experiences guilt and is consumed by paranoia and insecurity. He begins to imagine blood on his hands, and this image becomes a constant reminder of his crime. The sight of blood haunts him and becomes a visible manifestation of his inner corruption.
2. Metaphorical Use: William Shakespeare uses blood metaphorically throughout the play. Macbeth calls upon dark forces and spirits during the play, and these supernatural entities are often referred to as "instruments of darkness" or "spirits of death." Blood is linked with these malevolent forces, suggesting the corrupting influence of evil and ambition on Macbeth's soul.
3. Blood as a Motif: Blood is a repeated image throughout the play. Macbeth's first encounter with the witches is marked by their prophecy that he will become the Thane of Cawdor and eventually King of Scotland. These prophecies are accompanied by visions of blood, creating an eerie atmosphere and foreshadowing the bloody events to come.
4. Ritualistic Symbolism: Blood plays a role in certain scenes with ritualistic elements. For instance, in Act IV, Scene I, the witches' coven engages in a ritual involving blood as they stir a cauldron and utter their prophecies. Blood, in this context, represents the shedding of life and the invoking of supernatural forces.
5. Irony and Justice: Blood is also used to highlight irony and poetic justice in the play. When Lady Macbeth tries to wash away the imaginary blood from her hands, she becomes tormented by guilt and eventually descends into madness. The blood symbolises her unwashable sins and the retribution she faces.
By utilising the motif of blood in various ways, William Shakespeare reinforces the play's themes of guilt, violence, and moral decay. The play explores the consequences of Macbeth's actions, conveying that blood signifies not only physical bloodshed but also the contamination and corruption of the human soul.