Perhaps the most obvious subject or theme in Macbeth is ambition and we see this with both Macbeth and Lady Macbeth. They are tempted by the idea that Macbeth will become king - Macbeth is not sure what to do but his wife is ruthless in getting what she wants - she views her husband as a coward and appears ready to do anything. Read more...
Loyalty and guilt are also strong themes in Macbeth. Duncan clearly values loyalty - he has the first Thane of Cawdor executed and rewards Macbeth by making him the new Thane. Shakespeare cleverly uses loyalty as a dramatic device as well - Duncan is in the middle of talking about 'absolute trust' when Macbeth walks in - we know he's already thought about killing Duncan, but for the moment he talks about 'the loyalty I owe' and his 'duties' to Duncan. Read more...
Another major theme is the supernatural - the idea that there are mysterious forces controlling what is happening in our lives. The very first characters we meet are the three witches, and their prophecies are what drives the story forward. In Shakespeare's time belief in witchcraft was very strong and many so-called witches were burnt at the stake. Read more...
The contrast between what is real and the appearance of something is also used by Shakespeare. The classic dagger scene, when Macbeth is not sure if he can trust his eyes, is only one of many references to this theme. For instance, he sees Banquo's ghost at the banquet and Lady Macbeth imagines blood on her hands. Read more...