Final answer:
A good theme for Act 4, Scene 3 of Macbeth is the struggle between good and evil, showcasing the forces consolidating against Macbeth's tyranny and the contrast between the honourable characters and the corrupt king.
Step-by-step explanation:
A good theme for Act 4, Scene 3 of Macbeth is the struggle between good and evil. In this scene, the forces that oppose Macbeth's tyrannical rule begin to consolidate, highlighting the struggle for moral and political order. The conversation between Malcolm and Macduff presents a test of loyalty and discernment, while expressions of grief and anger over Scotland's suffering under Macbeth's rule emphasize the contrasts between the honourable characters and the corrupt king.
A significant line encapsulating this struggle comes from Macbeth's earlier reflection: 'False face must hide what the false heart doth know.' This underlines the deceit inherent in Macbeth's actions and his internal struggle with the consequences of his ambition. Additionally, Macduff's grief-stricken lines about his family's murder and his resulting desire for revenge serve as a catalyst for the ultimate confrontation between good and evil.