Fear of Banquos Ghost in Macbeth by William Shakespeare
Fear is perhaps one of the most primal and basic human emotions. In many instances it is because of a reaction to this emotion that humans are able to make crucial decisions to their survival. In the ancestral environment, a proper response to fear or the "fight or flight" reflex often made the difference between life and death. Those humans foolhardy enough to tease the sabretooth tiger to impress the ladies may have made their point a few times, but quite often they ended up as a tasty meal. Clearly, fear is then an useful thing for evolution to pass along to following generations.
Yet modern fear is so much more complex and convoluted than that of ancient man. Even in the times of the middle ages where Macbeth takes place, the subtle compound nature of what people could fear and to what degree is staggering in comparison. At its most basic level, fear is useful because it can help the individual to survive situations by making them aware of inherent risks in their current situation. In the play, fear -or its conspicuous absence- are pivotal in helping to determine how characters are going to behave and what courses of action they will follow. However, due to the more elaborate nature of social roles, the proper course of action is no longer as simple as merely avoiding the sabretooth.
In the play, Macbeth's fear is particularly noteworthy because of its relation to his state of mind. The more overcome he is by fear, the less stable and more neurotic he becomes. Prior to killing Duncan the vision of a floating dagger begins to unnerve him, particularly when he sees on "[the] blade and dudgeon, gouts of blood" (Act 2 Scn 1 Ln 46) which he realizes is related to his pending murder of the king. But the apprehension he has fails to make him reconsider his actions and instead serve to cement his resolve to go through with his plan of killing Duncan. Once his decision is made, he wishes that the "sure and firm-set earth, Hear not my steps, which way they walk, for fear Thy very stones prate of my whereabout" (Act 2 Scn1 Ln 56-58).
Macbeth's concern at this point has been somewhat attenuated and indeed subdued well enough to allow him to commit the deed. However, his speech after the fact confirms that he has not accepted the murder completely and now is beginning to have second thoughts about what he has done. Indeed, he is "afraid to think what I have done, Look on't again I dare not." (2:2 50-51) What he expresses is not necessarily regret about killing Duncan, but indeed fear at the very strong possibility that it will catch up to him. Fear now has reduced him to inability and throughout his ranting becomes dependent on Lady Macbeth to clean his hands and steer him away from the knocking. She remarks to him "Your constancy has left you unattended" (2:2 67-68) and has to shepherd him back to their quarters.
Curiously, it is Macbeth's capacity for fear and to a lesser degree regret...