Final answer:
Lady Macbeth's motivation to plan Duncan's murder is excessive ambition for her husband.
Step-by-step explanation:
The Tragedy of Macbeth: Motivation of Lady Macbeth
The character flaw that most seems to motivate Lady Macbeth to plan Duncan's murder in Act I of The Tragedy of Macbeth is her excessive ambition for her husband. Lady Macbeth is willing to go to extreme measures to ensure her husband becomes king, even if it means committing murder. Her ambition drives her to manipulate and persuade Macbeth to carry out the murderous plan, highlighting her flaw.
Despite the initial thoughts that her motivation might be fear of losing her husband in battle or insecurity about whether her husband really loves her, these options do not align with Lady Macbeth's actions and dialogue in the play. Her primary driving force is her ambition for power and control.
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