Loyalty and disloyalty are both major themes in William Shakespeare’s Macbeth. The play opens as the Thane of Cawdor is revealed as a “disloyal traitor” (I, ii, 54), who turns against his countrymen.
His disloyalty begins the play, just as the disloyalty of Macbeth, Thane of Glamis, who later kills his king to take his place, continues it, and the loyalty of Macduff, Macbeth’s nemesis, finishes it. In contrast to Macbeth, Macduff and others are so loyal to their country that they risk their lives undermining him. In the play, Shakespeare toys with the idea that loyalty implies disloyalty, and visa versa. Macduff risks his life due to his loyalty to Scotland, but in the same way the Thane of Cawdor risks his life by being disloyal to his country, but loyal instead to Norway. In much the same way, Macbeth is disloyal to his king, but he is loyal to himself and his ambitions of sovereignty.
Macbeth discovers his destiny as king when three witches tell him of it, and he quickly formulates a plan to kill Duncan, the current king and also Macbeth’s cousin, in his sleep. He has only one impetus to kill Duncan, and that is “vaulting ambition” (I, vii, 54), which outweighs his logic and his sense of right. He does, though, acknowledge the treacherousness of his plan and explains what he finds wrong with killing Duncan, who is his cousin, his king, and his houseguest:
First, as I am his kinsman and his subject
Strong both against the deed; then, as his host,
Who should against his murderer shut the door,
Not bear the knife myself.” (I, vii, 13-16)
Macbeth, who “shalt be king hereafter” (I, iii, 50), knows what he is doing is wrong, but he only thinks of his own aspirations. The three witches tell Macbeth that he is the Thane of Glamis, he will be the Thane of Cawdor, and he will be king. Soon after, he finds out that he has, in fact, been appointed as the Thane of Cawdor. “Two truths are told, / As happy prologues to the swelling act of the imperial theme.” (I, iii, 128-130), he says after he discovers his new position, but he doesn’t realize that, as happy as the prologues may be, the final outcome is entirely unhappy for him.
The play ends with the death of Macbeth at the hands of Macduff. Macduff firmly believes in Scotland and wants what he thinks is best for it, and what he thinks is best is for Macbeth to be dethroned and replaced by Duncan’s son, Malcolm. His loyalty sends him to England to seek out Malcolm and military aid so that he may dethrone Macbeth
“Thriftless ambition, that will ravin up/ Thine own life’s means!” (II, iv, 28-29)