One of the main motifs of the play is the decay of corruption. The development of both characters mimics the development of a disease. In a sense, Macbeth is a remake of the play Hamlet that has somewhat of a “happy ending” though centered not on Hamlet but on the usurper, Claudius.
The disease motif is quite evident as the play starts with a storm over a Scottish moor. The storm is like a feverish disease that attacks the body of the Scottish land and it foreshadows the decay and putrefaction that Macbeth’s ambition will bring upon Scotland. This is further exemplified by the introduction of the three witches; they are old, ugly, haggard and dirty. Macbeth is introduced as a courageous hero who kills a traitorous Scotsman. In other words, Macbeth is symbolically healthy, in his prime, both physically and morally. The infection occurs when the witches address him as Thane of Cawdor, and it is interesting to note that Banquo is NOT infected by the prophecies, just like some people are more vulnerable to diseases than others (usually because of a genetic predisposition). Macbeth resists contagion for a moment but quickly starts succumbing to it. Then his wife, Lady Macbeth (why is she unnamed?) is infected as well and she definitely has no “antibodies” for she succumbs very quickly to the disease. Due to the fact that she is the one that pushes Macbeth to regicide, she is like a personification of the Biblical Eve. Macbeth still tries to resist, but Lady Macbeth taunts him about his manhood and he finally falls. In act II there is even an interesting comic conversation between Malcolm and a porter about how alcohol provokes sleepiness, red noses and peeing further. In other words he is describing the symptoms of a disease and foreshadowing the effects of Macbeth’s contagion on Scotland. During the banquet, Macbeth sees Banquo’s ghost, though nobody else does, like the feverish hallucinations of a sick man. The sickening corruption will be further personified by Hecate, the returning witches and later by Lady Macbeth’s sleepwalking which is an actual disease, as she finally evolves into madness. There is even a doctor at the hall of Dunsinane which further emphasizes the disease motif by his mere presence. Lady Macbeth dies by killing herself and Macbeth dies by the sword of Malcolm. The infected lady Macbeth kills herself to escape her disease and Malcolm uses a symbolic scalpel to extirpate the cancerous Macbeth from Scotland.
