In the play, Shakespeare's Macbeth changes from a noble and respected soldier to a ruthless warrior, due to trying to fulfil his ambitions instead of following his conscience. This came from witches' predictions that he was going to be the King of Scotland.
At the beginning of Act 5, Scene 3, Macbeth seems over-confident, with full faith in the spirits that prophesise that he will not be killed by anyone who is born of a woman. Even though his servant brings him reports of an attack being launched against him, he refuses to be scared, because he believes the witches, since all their previous predictions had come true. However, he does not know that Malcom was not ˜born' of a woman, but instead brought out of one using a caesarean. His lack of fear and his faith in the witches' predictions are illustrated when he says to the servant: ˜I cannot taint with fear. / What's the boy Malcolm? / Was he not born of a woman? The spirits that know / All mortal consequences have pronounced me thus.' This shows that Macbeth is not afraid of being killed by Malcolm, because of what the spirits told him.
This is a big change from Macbeth's character at the beginning of Act 1, Scene 7, when he is unconfident and unsure about whether what the witches told him is true. He is also extremely hesitant about whether murdering the current king is the right way to fulfil their predictions. He is insecure and confused, as he shows in his soliloquy, during which he goes through a few changes of mind.
At first, he thinks that if he is going to murder King Duncan, he might as well get it over and done with, before he has time to think about what he is doing and let his conscience change his mind. This is shown when he says ˜If it were done, when ˜tis done, then ˜twere well / It were done quickly' This shows that he is aware that what he is considering doing is wrong, and that h