Examine the significance of the witches in Macbeth?

The witches prove significant throughout Macbeth. Shakespeare utilises the witches as a literacy construct as their presence act as a gothic and dramatic feature throughout ‘Macbeth’.
The opening act of the play immediately introduces the audience to a ‘desolate place’ in where the witches seem to inhabit. As the witches are the first characters to appear, it would suggest that they are one of the main characters, despite only appearing in four scenes. This, in effect, would make the witches seems insignificant in the play as they have a lack of physical presence. However, as they appear in the opening act, they instantly add an essence of gothic and dramatic feature especially when they mention ‘’there to meet with Macbeth’’. Despite this only being a first mention of Macbeth, the audience are already prompted to associate the witches with him. As of this, the next scene in which we hear Malcolm and Duncan call Macbeth ‘’Brave’’ and ‘’Noble’’, adds a contrast with the negative and evil connotations of the witches. Furthermore, when the witches chant there philosophy ‘’fair is foul and foul is fair’’, it is seemingly repeated by Macbeth when he states ‘’so foul and fair a day’’, which further adds to our association with the witches and Macbeth. However, this indicates that evil already looms in Macbeth’s persona, which suggests that the witches had no input in transforming Macbeth into a bloodthirsty, murderous character, as he was already this initially. This would then imply that the witches are not as significant, especially in the involvement of Macbeth’s downfall.
Yet, in recognition of this, the witches still trigger Macbeth’s dark desires. When, the witches prophesy that Macbeth will become Thane of Cawdor ‘’and king thereafter’’, he already triggered to act impulsively. But when it is discovered that one prophecies has already been proven true Macbeth reveals to the audience that he yields ‘’to that suggestion/ whose horrid image doth unfix my hair’’. The fact that Macbeth is already triggered to think murderously, shows how the witches have already fixated the thought into Macbeths mind. Yet, it is only when Lady Macbeth hears of these prophecies in act 1 scene 4, which causes the thought of murder to become a plan of action. Lady Macbeth seems to be enthralled by the thought of becoming queen that she transform herself into an evil character. She significantly calls upon evil spirits to ‘’fill her from the crown to the toe of cruelty’’ The urgency of ‘’come, you spirits’’ suggest that she has witch like characteristics as she hasn’t dwelled or thought about the danger of having the assistance of evil spirits. Furthermore, the fact that Lady Macbeth intentionally wants to manipulate her husband through the evil and supernatural means, it shows how significant the witches and the supernatural is. As the witches successfully also want to intentionally manipulate Macbeth as shown in act 3 scene 5 when they state ‘’as by the strength of their illusion/shall draw him on his own confusion’’.

Also, as of the association with evil, the setting of Macbeths castle is