Final answer:
The importance of Willy's lines reflects his psychological state and emphasizes the play's central themes, particularly in relation to his family dynamic and personal aspirations.
Step-by-step explanation:
The lines spoken by Willy at the end of page 51 as Ben is leaving are significant because they often reveal the inner workings of Willy's mind and underscore the central themes of the play. In Arthur Miller's 'Death of a Salesman', the characters' dialogue is pivotal in showing not only their relationships but also their psychological states and the overall message of the play. For example, Willy's phrases can indicate his desperation, his aspirations, and the tension in his relationship with his family.
Similarly, in the context of 'Lewis and Clark Disagree', the positioning of lines such as 'left him' and 'when he wasn't looking' can convey underlying meanings of abandonment and sneakiness, respectively, which serve to highlight the conflict between characters and the emotional tone of the scene. The importance of such lines lies in their ability to encapsulate complex emotions and to reflect the potential discord or harmony between characters, thereby deepening the audience's understanding of the narrative and its protagonists.