In Act IV Malcolm suspects that Macduff is an agent of Macbeth and wonders why Macduff left his family unprotected by going to England. To test his suspicions, he tells Macduff that he himself loves women, jewels, and discord among people:
...but there's no bottom, none,/In my voluptuousness: ...Your matrons and your maids, could not fill up/The cistern of my lust, and my desire...(IV, iii, 60-63)
He continues to state that he possesses no admirable qualities of rulers, no fairness, honesty, kindness, strength of character, stability, devotion, bravery, or patience:
But I have none: the king-becoming graces,/ As justice, verity, temp'rance, stableness,/Bounty, perseverance, mercy , lowliness, /Devotion, patience, courage, fortitude,/I have no relish of them, but abound/In the division of each several crime/Acting it many ways (IV, iii,91-97)
But when Macduff responds with a cry of despair and hopelessness for his country, Malcolm tells him that what he has said is a lie, the first lie he has ever told:
Macduff, this noble passion,/Child of integrity, hath from my soul/Wipe the black scruples, reconciled my thoughts/To thy good truth and honor. (IV, iii, 115-119).
Malcolm then goes on to state that he is
yet/ Unknown to woman,,,,scarcely have coveted what was mine own,/At no time broke my faith, would not betray/The devil to his fellow, and delight/No less in truth than life(IV,iii,124-128).
After Malcolm declares that he does, indeed, possess virtue, Macduff is nonplused and says that he does not know what to believe: "Such welcome and unwelcome things at once/'Tis hard to reconcile" (IV,iii,137-138).
However, Malcolm is what he says he is. For, he later encourages Macduff to use the sudden news of his family's slaughter as a reason to fight Macbeth. And, he assumes the role of kingship with dignity and honor in the final act. In his final speech, he inaugurates a new era for Scotland:
As calling home our exiled friends abroad/That fled the snares of watcful tyranny,/...We will perform in measure, time, and place:/So thanks to all at once and to each one,/Whom we invite to see us crowned at Scone (V,iii,66-75).