Macduff exhibits the qualities of honor and valor that characterize the heroic ideal. In the beginning of Act IV, Scene 3, Malcolm wants to mourn the sad fate that has befallen Scotland, but Macduff wants to take action to "hold fast the mortal sword, and like good men, bestride our downfall'n birthdom" (lines 4-5). Although the wisdom of his decision is often called into question by critics, Macduff has left behind his wife and children, traveling to England to raise an army to fight Macbeth. When Macduff learns at the end of this scene that his family has been murdered, he allows himself a moment for grief, then gathers himself and vows to avenge himself and save Scotland, bravely exemplifying the heroic ideal.
Macduff also demonstrates the qualities of humanism and reason that is characteristic of the Renaissance man. When Malcolm, in an attempt to measure Macduff's loyalty to his country, paints himself as a potential ruler with more vices than Macbeth, Macduff at first tries to rationalize the faults he lists in order to convince Malcolm, and himself, that no matter how bad a person Malcolm might be, he could not be worse than Macbeth. In doing so, Macduff almost fails the test with which Malcolm is trying him, but he realizes in time that, if what Malcolm says is true, then there is no hope for Scotland. Reason, though fallible, is central to the approach of a man of the Renaissance towards life, and Macduff demonstrates this orientation in trying to justify what is best for Scotland.
Macduff is also a man of feeling, showing a level of humanism also characteristic to the Renaissance man. When he learns of the murder of his family, Malcolm immediately tells Macduff to "dispute it like a man" (line 256), but Macduff insists on first allowing himself to grieve, telling Malcolm that though he will certainly rise up to avenge himself, he must first "feel it as a man...(he) cannot but remember such things were, that were most precious to (him)" (lines 258-260).