Shakespeare uses the night to convey evil and most of the action in the play takes place at night.
In Act 3 scene 2 (a relatively short scene of 56 lines) Macbeth has planned the murder of Banquo having previously murdered Duncan the rightful King, at this point Lady Macbeth is unaware that Macbeth has set in motion the murder of Banquo. Macbeth tries to hide this impending murder from his wife with the words "Be innocent of the knowledge, dearest chuck,/Till thou applaud the deed.." Macbeth then speaks the words "Come, seeling night" to hide the murder in darkness which shows that night is a time of evil. Seeling is a form of blinding as carried out on a hawk's eyes.
Macbeth and Lady Macbeth talk of the terrible nightmares and loss of appetite they are suffering from. Macbeth states "In the affliction of these terrible dreams/That shake us nightly; better to be with the dead./Whom we, to gain our peace, have sent to peace". Sleep is a natural restorative, and Macbeth is suffering from insomnia showing that as he is awake at night unable to sleep he has become a creature of the dark, and therefore unnatural.
Macbeth states to Lady Macbeth that "We had scotch'd the snake, not kill'd it." The snake in this context is a metaphor of deceitfulness and treachery. This quote means that as Macbeth has harmed the snake, not killed it, it will return to haunt him probably in the form of the murdered rightful King Duncan's sons. By killing Duncan, Macbeth is a traitor and has committed treason and an unnatural occurrence.
Macbeth continues to explain the pain Duncan's death has caused him; "Oh full of scorpions in my mind, dear wife!" This metaphor explains that Macbeth's thoughts are evil and that he is slowly going mad.
In scene 3 of the same Act, following the murder of Banquo one of the murderers ask "who did strike out the light?" light is used as a metaphor to show that Banquo was a good person.
In this act Shakespeare uses many occurrences of natural imagery in the form of animals to portray evil. For instance, "scarf up" and "seeling" both refer to birds of prey having their eyes covered. "and the crow/Makes wings to the rooky wood" which allows the audience to see that Macbeth is being connected to birds of a nocturnal and predatory nature. Another night time animal is used in; "ere the bat hath flown/His cloister'd flight." The bat is a nocturnal animal and at that time (the 17th century) would have been considered evil and related to witchcraft.
At the banquet the ghost of Banquo appears and Macbeth becomes obsessed with the amount of blood the murdered body of Banquo produced. Shakespeare uses imagery to set contrasts between life and death and the conflict between the two, whilst at the same time showing us the state of Macbeth's mind and his descent into insanity with the lines "It will have blood; they say, blood will have blood:/ Stones have been known to move and trees to speak;/ Augurs and understood relations have/By maggot-pies and choughs and rooks brought forth/The secret'st man of blood. What is the night?"
During the 17th century it was still not clear if witches and the supernatural were real and the examples above show Shakespeare's use of imagery to play upon the audience's fear of the unknown. They illustrate the fact that Macbeth is truly malevolent; he is awake during the night a time when the supernatural and evil was thought to occur and is being associated with animals who were at the time thought to be evil or related to witchcraft.
In Act 4 Macbeth seeks out the witches again and decides to murder Macduff's family. Macduff has left Scotland to seek help from the English King against Macbeth.
The three witches in the play are malevolent forces of evil and Shakespeare has portrayed them as people would have imagined them at that time. Macbeth is susceptible to their influence as he hears them say what he really desires, ie power and kingship. In Act 4 the witches chant around the cauldron "Fillet of a fenny snake,/ …/Eye of newt and toe of frog./Wool of bat and tongue of dog,/Adder's fork and blind worm's sting,/Lizard's leg and owlet's wing." and continue in the same vein adding more parts of animals to their brew along with "Liver of blaspheming Jew/…/Nose of Turk and Tartar's lips/" All are examples of natural imagery, whilst the concoction itself is totally unnatural, used by Shakespeare to portray dread and fear and evil, the animals are all either associated with witchcraft, mythology or are contaminated in some way, whilst the Jew, Turk and Tartar are seen as non-Christian and therefore people not to be trusted in the 17th century.
Macbeth commands the witches to bring forth apparitions to answer his questions. The first apparition warns Macbeth to be wary of Macduff, however the second apparition tells Macbeth he has nothing to worry about "The power of man, for none of woman born/Shall harm Macbeth" whilst the third apparition tells Macbeth he has nothing to worry about until "Great Birnam wood to high Dunsinane hill/Shall come against him." When Lennox appears to tell Macbeth that Macduff has fled to England Macbeth decides to murder Macduff and all his family with the words "Seize upon Fife; give to the edge o' the sword/His wife, his babes and all unfortunate souls/ That trace him in his line." Macbeth is now obviously totally evil and is paranoid.
In Act 4 the differences between the two female characters Lady Macbeth and Lady Macduff become apparent. Lady Macbeth represents evil and unnatural womanhood – we know that Lady Macbeth is unable to have children. Whilst Lady Macduff represents good and natural womanhood as she has several children and she cares about her family. In the lines "for the poor wren,/the most diminutive of birds, will fight,/Her young ones in her nest against the owl." Shakespeare is describing Lady Macduff as a wren and Macbeth as an owl, these images are metaphors to help the audience understand that whilst Lady Macduff is a woman and not a soldier she will fight to the death to protect her family from the evil Macbeth.
In the 17th century it was expected that a woman would have many children and stay at home to look after them and to be gentle and loving. Shakespeare has ensured that the audience sees Lady Macduff in this light as a pure and good woman. Lady Macbeth, however, has been shown to be evil, taking part in the murder of King Duncan, and has no children. The image that Shakespeare conjures up of the two women is of one who is good and the other who is evil and that although good is better than evil, sometimes evil is the stronger.
The key themes, of good and evil and sickness and health, in this play are all seen in Macbeth. He starts off as a good character but ends up totally evil. "I am in blood/Step'd so far that, should I wade no more,/returning were as tedious as go o'er" (Act 3 scene 4) shows that at this point Macbeth realises that murder and treason have led him astray and there is no way back to the right path. He is losing his mind as can be seen from Act 4 with the appearance of the ghost of Banquo that no one else can see. This sickness and evilness show that Macbeth has become unnatural.
Shakespeare uses Macbeth's insomnia to illustrate how unnatural Macbeth has become. Sleep is a natural restorative, as Macbeth is suffering from insomnia, this shows again that Macbeth is unnatural. Natural imagery as stated above includes love and loyalty, with the unnatural being treason and betrayal Macbeth envies the dead King Duncan and wishes that he could sleep the sleep of the dead "sleep/In the affliction of these terrible dreams .. better to be with the dead".
Shakespeare uses the night in the play to carry out all Macbeth's evil deeds. The imagery of the night is used to convey evil and unnatural creatures that at the time were associated with witchcraft, such as owls and bats.
Family and children are used as a form of natural imagery in the play, we know that Macbeth and his wife have no children which is unnatural, whilst, King Duncan, Banquo and Lord Macduff all have families which is natural.
In conclusion Shakespeare's use of imagery supports the main themes of the play enabling the audience to understand the characters better and to see the differences between good and evil, sickness and health. It also allows the audience to understand how it is possible to start out as a good person but to end up totally evil as in the case of Macbeth. Imagery also allows Shakespeare to use the play to voice his own thoughts on the political situation of the day.
