Witches

• Whilst the supernatural can be deemed as largely influential in Macbeth's downfall, the "weird sisters'" ambiguity throughout the play, as well as their struggle for power in a patriarchal society, suggest Shakespeare may have only implemented the supernatural in his play to appease King James I who was his patron. Shakespeare was more interested in the psychology of the characters; the supernatural were simply a symbol of temptation that Macbeth was consumed by. 
• Shakespeare introduces the witches in the very first scene of the play which gives them large structural significance. They chant “Fair is foul and foul is fair”. This paradoxical chiasmus is a logical inconsistency that introduces the play's strong underlying theme of corruption and the supernatural. 
• The witches speak in trochaic tetrameter which is distinguishes them from the other characters who typically speak in iambic pentameter. This would unsettle a Jacobean audience who were largely scared of the supernatural. King James was especially interested in it - shown by his book Daemonologie and the witch hunts he organised. The weird sisters continue to use equivocation, declaring “when the battle’s lost and won”, unsettling the audience with its ambiguity by flipping the conventional order of “won” first. This alludes to the idea of Macbeth’s downfall coming first. 
• However, Shakespeare could be diminishing the influence of the witches in the events of the play as they speak in an almost childlike manner due to their short sentences, simple rhymes and choral speech, as if they were children playing a game. This undermines their credibility as it shows the audience their game does not have any real power; they only serve as a mirror for the recognition of each character's true self. 
• Shakespeare demonstrates how temptation and the supernatural invokes an irreversible change in character, subverting the audience’s expectations as he implies that a person’s poor qualities are amplified by the crown and supernatural. Macbeth becomes paranoid, but the weird sisters simply reveal his true self, as a killer.
• Macbeth echoes the witches' equivocation in Act 1 Scene 3 "so fair and foul a day I have not seen". By this point in the play, Macbeth had not yet met the witches which could allude to some form of supernatural power the witches have over Macbeth. Alternatively, Shakespeare could be suggesting that Macbeth is already evil and corrupt and his demise is destined due to his “vaulting ambition”.
• In fact, in Act 1 Scene 3, Macbeth says “chance may crown me//Without my stir” with the verb “stir” alluding to himself. The witches show he can be crowned “without” any action from himself, suggesting that Macbeth recognises he does not need to do anything to become king. Yet he kills Duncan anyway because of his “vaulting ambition which o’erleaps itself and falls on th’other”.  
• “vaulting ambition which o’erleaps itself and falls on th’other”

  A dactylic metre is used in this quote which is reminiscent of the sound of a galloping horse, perhaps suggesting the relentlessness of Macbeth’s ambition: a persistent driving force that is only catalysed by the manipulation of the witches and Lady Macbeth.
• The witches’ power appears only to be deception. This is exemplified at the end of the play when Macbeth says “And be these juggling fiends no more believed”. The gerund “juggling” in this sense means trickery and alludes to the deception of the witches in manipulating him to his demise by capitalising on his hamartia. The “fiends” are what Shakespeare wants the audience to see the supernatural as - nothing more than deceitful game players. Perhaps he wishes James I would also realise this, but he cannot say this explicitly as he might be executed for witchcraft.
• the supernatural are dependent on the person they are acting upon. Macbeth’s violence was already evident before he met the witches when the sergeant described Macbeth’s steel as “smoked with bloody execution” and the witches simply catalysed the inevitable.
• However, Banquo was faced with a similar prophecy and yet is symbolic of the route Macbeth didn’t take. He is the antithesis to Macbeth’s tragic hero, and consequently he ended with the long-lasting lineage of descendants on the throne. As King James I was believed to have been a descendant of Banquo, Shakespeare ensures to portray him in a morally virtuous and positive light to continue his flattery of the king, and to show the nobility the virtue of not giving in to ambition. 
• Overall, Shakespeare presents the true crux of the play as temptation and hides this behind the facade of the supernatural to appease the king. Temptation’s relationship with each of the characters differs slightly, but when Macbeth and Lady Macbeth succumb, Shakespeare uses their mental decline to ruin every pleasure of usurping the throne, and he uses their violent and shameful deaths as a cautionary tale against sacrificing one’s Christian soul for ambition.