How we cite our quotes:
THIRD WITCH All hail, Macbeth, thou shalt be king hereafter! […] Thou shalt get kings, though thou be none: So all hail, Macbeth and Banquo! (1.3.4-6)
Tra-la-la, there goes Macbeth innocently walking along when all of sudden the witches show up to tempt him by talking about the awesome power that's going to be his. Right? Or are they just giving voice to his secret desire?
MACBETH […] If good, why do I yield to that suggestion Whose horrid image doth unfix my hair And make my seated heart knock at my ribs, Against the use of nature? Present fears Are less than horrible imaginings: My thought, whose murder yet is but fantastical, Shakes so my single state of man that function Is smother'd in surmise, and nothing is But what is not. (1.3.9)
History Snack: Regicide was a pretty common occurrence in 11th century Scotland, the time period of Macbeth,but it definitely was not common in early 17th century England. The Divine Right of Kings said that monarchs were God's appointed representatives on earth, so rebellion wasn't just treason—it would actually send you straight to hell. James even wrote about it in The Trew Law of Free Monarchies (1598), where he claimed that "The state of monarchy is the supremest thing upon earth; for kings are not only God's lieutenants upon earth, and sit upon God's throne, but even by God himself are called gods." In other words, Macbeth is meddling with power that he should seriously leave alone.
DUNCAN My plenteous joys, Wanton in fulness, seek to hide themselves In drops of sorrow. Sons, kinsmen, thanes, And you whose places are the nearest, know We will establish our estate upon Our eldest, Malcolm, whom we name hereafter The Prince of Cumberland; which honour must Not unaccompanied invest him only, But signs of nobleness, like stars, shall shine On all deservers. From hence to Inverness, And bind us further to you. (1.4.4)
When King Duncan names his son, Malcolm, the Prince of Cumberland, he's essentially naming him the heir apparent to the throne. Fun fact: he's seriously out of order here, since Scotland was an elective monarchy at the time. This is all Macbeth needs to decide that Malcolm and King Duncan are nothing but an obstacle in his path to ultimate power.