Final answer:
In Macbeth, Lady Macbeth keeping a light by her symbolizes her fear and guilt, and illuminates her mental state as darkness in the play connects to evil and the supernatural.
Step-by-step explanation:
In Act 5, Scene 1 of Macbeth, there is a significant moment when the gentlewoman reveals that Lady Macbeth keeps a light by her continuously. This small revelation represents Lady Macbeth's deep-seated fear and guilt after being involved in King Duncan's murder, as the light symbolizes her attempt to ward off the darkness, which often represents evil or the unknown. The motif of sleep and darkness throughout Macbeth encapsulates deceit, betrayal, and the supernatural, making this moment of visual imagery crucial in understanding Lady Macbeth's mental state as she descends into madness.