That heart-sickness which comes from Macbeth’s perception of the futility of his crime, and which never leaves him for long, is not, however, his habitual state.  It could not be so, for two reasons.  In the first place the consciousness of guilt is stronger in him than the consciousness of failure; and it keeps him in a perpetual agony of restlessness, and forbids him simply to droop and pine.  His mind is ‘full of scorpions.’  He cannot sleep.  He ‘keeps alone,’ moody and savage.  ‘All that is within him does condemn itself for being there.’  There is a fever in his blood which urges him to ceaseless action in the search for oblivion.  And, in the second place, ambition, the love of power, the instinct of self-assertion, are much too potent in Macbeth to permit him to resign, even in spirit, the prize for which he has put rancours in the vessel of his peace.  The ‘will to live’ is mighty in him.  The forces which impelled him to aim at the crown re-assert themselves.  He faces the world, and his own conscience, desperate, but never dreaming of acknowledging defeat.  He will see ’the frame of things disjoint’ first.  He challenges fate into the lists.

The result is frightful.  He speaks no more, as before Duncan’s murder, of honour or pity.  That sleepless torture, he tells himself, is nothing but the sense of insecurity and the fear of retaliation.  If only he were safe, it would vanish.  And he looks about for the cause of his fear; and his eye falls on Banquo.  Banquo, who cannot fail to suspect him, has not fled or turned against him:  Banquo has become his chief counsellor.  Why?  Because, he answers, the kingdom was promised to Banquo’s children.  Banquo, then, is waiting to attack him, to make a way for them.  The ‘bloody instructions’ he himself taught when he murdered Duncan, are about to return, as he said they would, to plague the inventor. This then, he tells himself, is the fear that will not let him sleep; and it will die with Banquo.  There is no hesitation now, and no remorse:  he has nearly learned his lesson.  He hastens feverishly, not to murder Banquo, but to procure his murder:  some strange idea is in his mind that the thought of the dead man will not haunt him, like the memory of Duncan, if the deed is done by other hands.[222] The deed is done:  but, instead of peace descending on him, from the depths of his nature his half-murdered conscience rises; his deed confronts him in the apparition of Banquo’s Ghost, and the horror of the night of his first murder returns.  But, alas, it has less power, and he has more will.  Agonised and trembling, he still faces this rebel image, and it yields: 

                       Why, so:  being gone,
     I am a man again.

Yes, but his secret is in the hands of the assembled lords.  And, worse, this deed is as futile as the first.  For, though Banquo is dead and even his Ghost is conquered, that inner torture is unassuaged.  But he will not bear it.  His guests have hardly left him when he turns roughly to his wife: