Bloody Daggers and Hands

Blood shows up a lot in this play. Blood as a result of actual wounds is almost omnipresent, from the bleeding Captain in the beginning to Macbeth's bleeding head at the end. But it's the imagined blood that arguably has the biggest impact as a symbol. When Macbeth considers murdering Duncan, he sees a floating "dagger of the mind" that points him in the direction of the sleeping king's room (2.1.6). As Macbeth wonders if his mind is playing tricks on him, the dagger becomes covered in imaginary blood, which anticipates the way that very real daggers will be soiled when Macbeth murders King Duncan.

Still, it's not clear where the image comes from. Did the witches conjure it up? Is it a product of Macbeth's imagination? Is Macbeth being tempted to follow or warned not to pursue the hallucination? Eventually, imagined blood comes to symbolize guilt for both Macbeth and Lady Macbeth. After he murders Duncan, Macbeth supposes that even "Great Neptune's ocean" could not wash away his stain of guilt (2.2.13). This, of course, is in response to Lady Macbeth's command that Macbeth "go get some water / And wash this filthy witness" from his hands (2.2.10). The idea that water alone could cleanse the pair after such a foul deed seems laughable, especially when Lady Macbeth famously curses the imaginary "spot" of blood she can't seem to wash from her guilty hands (5.1.1). After Macbeth kills his friend Banquo, who returns as a ghost, Macbeth announces that blood will beget blood, and his image of wading in a river of blood sums up the lesson: once you've gone far enough in spilling it, you might just as well keep on going (3.4.24).