By careful study of the play, decide, in committing Duncan's murder, how far Macbeth is driven by his ambition, how far he is dominated by his wife's and how far he is influenced by the witches.
Macbeth was pushed into committing Duncan's murder by his own ambition as well as his wife's ambition. The witches also played a part by influencing Macbeth's choice to kill Duncan.
When the witches first told Macbeth that he would become first the Thane of Cawdor then eventually the King, curiosity was only aroused. He shows this by saying to the witches, "Stay, you imperfect speakers. Tell me more." He wanted to know more about his future and more importantly, how was it that he would eventually become King. However, the witches vanish and leave Macbeth's questions unanswered. Macbeth's ambition first starts to show when the witches" premonition about him becoming the Thane of Cawdor comes true. He mentions "murder" while talking to himself but then he also says "If chance will have me king, why chance may crown my Without my stir", which shows that Macbeth was not yet fully driven by his own ambition as he already had two minds about the idea of murdering Duncan. One was that he would if it meant that he were to be king, but then the other side was that he shouldn't because it would mean killing another man. He struggles with the idea of killing Duncan just so that he could become king. Later on in the play, Macbeth says, "We shall proceed no further in this business. [Duncan] hath honoured me of late" which means that he does not want to carry out the murder. However, Macbeth is eventually pushed into killing Duncan. Before killing Duncan, he feels a great sadness as he says "tears shall drown the wind" but he also says that his "vaulting ambition" is the only thing that would make him carry out the murder. His ambitious side peaks when he hallucinates and the dagger appears before his eyes.