Here's how they influence Macbeth:
* They present prophecies: The witches tell Macbeth he will become Thane of Cawdor and then King. These prophecies, while seemingly favorable, spark ambition and a desire for power within Macbeth. He already has the seeds of ambition within him, and the witches' words act as a catalyst.
* They fuel his paranoia: The witches also predict Banquo's descendants will be kings, fueling Macbeth's fear and paranoia. This paranoia leads him to commit further acts of violence, including the murder of Banquo.
* They create a sense of inevitability: By suggesting Macbeth's destiny is already set, the witches make him believe he has little choice but to act on their prophecies. This removes some of the moral burden from his actions.
Important Note: Macbeth is ultimately responsible for his choices. He is the one who decides to act on the witches' prophecies, and he commits the murders of Duncan and Banquo of his own free will.
The witches, therefore, play a complex and influential role in Macbeth's story. They act as a trigger for his pre-existing desires, fuel his fears and paranoia, and create a sense of inevitability that allows him to justify his actions. However, they do not directly cause him to murder, and the ultimate responsibility for his crimes lies with Macbeth himself.