In this exchange between Macbeth and the Doctor, Macbeth expresses his deep anguish and desire for relief from his mental torment. He seeks an antidote to erase his painful memories and alleviate the emotional burden that plagues him. His desperation highlights the idea that he is trapped in his own troubled mind, longing for a solution that seems unattainable.

The Doctor responds by emphasizing that the path to healing must come from within the patient. This suggests that external remedies cannot fully cure Macbeth's psychological struggles; he must confront his internal issues himself. This dialogue reflects the themes of despair and the complexities of the human mind prevalent in Shakespeare's work.