The theme of disorder is important to both Macbeth and A Midsummer Night’s Dream because in both cases obsession turns to disaster.
Although Macbeth is certainly the darker tale, there are similarities in character actions. Macbeth is obsessed with gaining power at all costs. Hermia, Lysander, and Helena are all obsessed with each other. Egeus is so obsessed with deciding what his daughter can do that he would rather kill her than have her disobey him. In all the humor and fun, these are dark thoughts.
Obsession runs rampant in Macbeth. He is influenced my magic when the witches tell him that he will be king. It brings out his obsession, and it becomes all he can think about.
Stars, hide your fires;
Let not light see my black and deep desires:
The eye wink at the hand; yet let that be
Which the eye fears, when it is done, to see. (Act 1, Scene 4)
Once he gets the idea in his head, he cannot get it out. He is ready to do anything, even murder, to get what he wants. This obsession leads him to kill his friends and former colleagues, and even their families. It leads to his wife’s suicide, and his own destruction.
In A Midsummer Night’s Dream, most of the obsessions are about love and not power. With the exception of Egeus, most of the characters just want the person they love to love them back. Helena is so obsessed with Demetrius that she tells him that Hermia is planning to run away with Lysander, setting off a chain of events that gets them all lost in the enchanted forest for the night and almost coming to blows.
When the magic enters the equation, as in Macbeth’s case things get crazy. When the wrong lovers are anointed, the obsession turns violent.
What! Can you do me greater harm than hate?
Hate me! wherefore? O me! what news, my love?(280)
Am not I Hermia? Are not you Lysander?
I am as fair now as I was erewhile. (Act 2, Scene 2)
In the end, Oberon decides enough is enough and makes sure that Puck anoints the lovers’ back in the right pairs, and they end up back in love with the person they should be in love with. They are a little less obsessed, but still in love.
In either case, Shakespeare's message is the same. Love is a good thing. Ambition is a good thing. However, too much of either turns to disorder. There is nothing more dangerous than obsession. It can tear apart perfectly normal lives.