In William Shakespeare's "Tragedy of Macbeth" the tragic hero Macbeth sets himself up for his own demise. There is only one main cause of the downfall of Macbeth, which was him listening to the witches prophecies and letting them influence him. This is what leads Macbeth on the path to his sadistic down fall.
The outside influence in Macbeth's life was too great for Macbeth to over come. During the time the witches first met Macbeth they said in their third prophecy: "All hail, Macbeth! That shalt be king here after!" (I.i.56-57). The only human Macbeth seems to be a pond in the witch's hands. Contemplating to either listen to the witches or to listen to his dearest friend Banquo, the decision crushes Macbeth mentally as it leads to his insanity. The hole Macbeth falls into only gets bigger as he makes the decision to listen to the witches and kill the king.
As the hour comes near you see Macbeth's sanity run away with him saying: "Is this a dagger which I see before me. The handle toward my hand? Come, let me clutch thee: I have thee not, and yet I see thee still" (II.i.42-44). When Macbeth imagines a dagger in front of him it shows that he's starting to weaken.
Macbeth dug a hole too deep to dig his way out. The plot only thickens as the story progresses Macbeth is to far into his murders to get out. During the time then the tragic hero was speaking to Lady Macbeth he said: "I am in blood/ Stepped in so far that should I wade no more..."(III.iv.171-172). This only states that Macbeth is begging to regret what he has done but still wants to proceed with the killing any ways. The witches have uncovered Macbeth's true ambitions...