Before the murder of Duncan, Shakespeare portrays Macbeth as ambitious, and certainly capable of violence (as the accounts of his performance in battle show.) But he is certainly torn about the morality of murdering Duncan, and after he does so, he continues to feel remorse. Even after Banquo's murder, Macbeth still is haunted by his deeds, as the fact that he "sees" his dead friend at his banquet table suggests. From this point on, however, and especially after he consults with the witches for the second time, Macbeth becomes more and more violent, acting (significantly) without encouragement from his wife, who becomes the one afflicted with guilt. The murder of Macduff's wife and child marks a low point for Macbeth, who seems to have become a vicious tyrant. A man once torn by guilt over the murder of his king and kinsman is by the end of the play consumed by ambition and caught in a cycle of violence that he (and, one might add, his wife) unleashed.