'Proceeding from the heat-oppressed brain?' This shows that Macbeth is not purely evil and that he has a conscience. This could make it easier for Macbeth by reducing some of the blame that could be placed on him for the evil deeds, when we have seen that Macbeth did not commit this crime acting under his own intentions; but rather Lady Macbeth's.
What follows illustrates Macbeth feeling guilty. He cannot sleep, he feels that he has murdered sleep. In Shakespearean times sleep represented innocence. Lady Macbeth tells Macbeth that if he washes his hands there will be no reminder of the murder.
'A little water clears us of this deed:' This is an ironic comment on what Macbeth continues to say. 'Will all great Neptune's Ocean wash this blood.' Macbeth responds by saying that water will not get rid of his guilt. Blood symbolises evil and for Macbeth it is suspicion as he has become paranoid.
Banquo harbours suspicion about Macbeth. He realises that the guards had no motive to kill the king so he does not suspect them. He says that he is going to investigate the murder as there are hidden motives. He does not mention however his suspicions of Macbeth as his sons may also be kings too and is content that they should be. Banquo was much more naive than Macbeth. His was not totally surprised when he found out about the murder which would indicate that that he was prepared for such an event.
The next evil deed committed is the killing of Banquo, whom Macbeth fears knows too much.
'To be thus, is nothing, but to be safely thus.' Macbeth is indicating that he needs security to be King. His intention is to remove any threat to his throne. Macbeth is very calculated; he really knows what he is doing, more so than in the murder of Duncan. He acquires two murderers to kill Banquo. He manipulates them into believing that it was Banquo's fault that they are poor. 'That it was he in times past, that held you so under fortune,' Macbeth uses the same taunt that Lady Macbeth used against him, by insulting the masculinity of the murderers. Macbeth did not kill Banquo himself for a number of reasons. The detection was an issue, which also lead to the fear of Banquo's honesty. He feared Banquo would tell about Macbeth if he detected anything.
Macbeth has become deeply involved in the game. Macduff, because he did not turn up to the feast, probably has suspicion about Macbeth. Macbeth has to carry on killing so that he will not feel that because he is only a beginner, that this is where his fear is coming from.
He took it one step further when he began to kill good, innocent people. He killed Lady Macduff and her son. This shows his deterioration, also associated with Scotland's disorder.
'Sighs and groans and shrieks That rend the air, are made, not mark'd.'
Lady Macbeth can be seen as partly responsible for the deeds her husband committed. She had the main involvement in the murder of Duncan. In Act I, Scene V Lady Macbeth seems to be a woman unlike that of a typical Elizabethan stereotype. The audiences perception of this would have been that Lady Macbeth was purely evil. After reading the letter in her soliloquy, it is clear to the audience that she intends to help Macbeth achieve his ambition.
'The illness should attend it.'
Lady Macbeth is claiming that without the inherent evil Macbeth will not be King. The audience would have been shocked at the way Lady Macbeth was acting as it was unnatural for a woman of that time. She prays to the powers of darkness to make her become less feminine when she says 'unsex me here' so that she can have no natural feelings of pity and carry out the procedure selfishly. At the banquet, Lady Macbeth presents herself as a hostess. She acts like a woman with a warm heart and charm. This makes the murder a much more horrible crime; and more of a shock to the audience. She has no difficulty in hiding her real thoughts. This is another reinforcement of the theme 'Fair is foul, Foul is Fair.'
Her greed for the throne and power has made her become so deeply involved in this murder that some of the blame is reduced on Macbeth's part.
After the death of Duncan, Macbeth became more independent. In his planning of the death of Banquo and Fleance he did not tell his wife anything about it. There could have been a number of reasons for this. He probably felt that she would take control like she did when she found out about the witches' prophecy. He could have been trying to gain control, to prove he could do things himself. He could have also wanted to prove her innocence and so that she would not have to take the strain. It is important to note that Macbeth is doing this without the consultation of his wife and that none of Macbeth's actions to plunge deeper into evil have much to do with Lady Macbeth.
We see the isolation of Lady Macbeth towards Macbeth when her only concern for his welfare is; 'You lack the season of all natures, sleep'
We do not here about her again until Act V, Scene IV, where we witness Macbeth disclaiming ownership of his wife.
Macbeth is too weary to feel more than just a dull sense of loss and regret. He does not miss her influences though. She lost her influence along time ago when Macbeth became independent. Shakespeare makes the characters of Macbeth and Lady Macbeth very much as a linked pair. When Macbeth is weak, Lady Macbeth is strong; when Macbeth is determined, Lady Macbeth is tormented.
The witches and evil can play a small part in the final conclusion. Their prophecies encouraged Macbeth's ambition to be king. The witches told him he had nothing to fear because he could not be killed by a man born from a woman.
'The power of man: for none of woman born Shall harm Macbeth.'
With the minority of people today believing in the powers of the supernatural, it would be quite ludicrous to say that it was the witches that controlled the plot. Shakespeare writes his plays for the audience to not know what is going to be the final outcome before finishing the performance. If we knew this then consequently the action would become dull and predictable. The witches only played a small part in the evil deeds. It was Macbeth that chose his own fate by believing in the witches and giving into temptation both from the witches and the guidance from his wife.
In conclusion, Macbeth is, for the most part, responsible for the evil deeds. In Shakespearean times it may have been said that he was the victim of the powers of darkness such as when Lady Macbeth conjured up the powers of evil and prayed to the powers of darkness. Similarly, the witches who the Elizabethans would have believed to be a very real thing.