Final answer:
The evidence of Macduff's loyalty in Shakespeare's 'Macbeth' includes his reactions to Duncan's murder, his refusal to attend Macbeth's coronation, his flight to England to enlist Malcolm's help, and his confrontation with Macbeth, driven by a desire for justice and retribution.
Step-by-step explanation:
The question, "What evidence do we have that Macduff is loyal?", can be addressed by examining his actions and statements throughout Shakespeare's tragedy Macbeth. Macduff's loyalty is initially ambiguous; however, as the play progresses, it becomes evident.
After Duncan's murder, Macduff's distress and his decision not to attend Macbeth's coronation signal his suspicions and loyalty to the rightful king. Furthermore, his refusal to accept Macbeth's reign and his efforts to dethrone him by seeking Malcolm's help substantiate his steadfast loyalty. Notably, Macduff's ultimate act of loyalty is avenging Duncan's death by confronting and fighting Macbeth, despite the personal risks.
In Act I, Macduff's loyalty to Duncan is implied when he respects the king's decision to execute the previous Thane of Cawdor for treason and immediately acknowledges Macbeth's new title. Moving to Act II, Macduff discovers Duncan's body and appears genuinely shocked and outraged, suggesting his allegiance to the king.
His subsequent actions, such as not attending Macbeth's coronation and fleeing to England to join Malcolm, further demonstrate his loyalty to the Scottish throne and his disapproval of Macbeth’s illegitimate rule. Macduff's sentiment, "That would make good of bad, and friends of foes!", highlights his commitment to rectifying the tragic situation and restoring the rightful order in Scotland.
Macduff's confrontation with Macbeth in Act V represents the climax of his loyalty. Macduff challenges Macbeth, driven by a desire for justice and retribution for Macbeth's tyranny and the murder of his own family. In doing so, Macduff solidifies his position as a loyal Scottish patriot, determined to rid his country of a despot and avenge the wrongs done to his nation and family.