Macbeth is a play of both character and atmosphere. Sleeplessness is one of its many important themes. Conscious and thinking subjects have a capacity and need for unconsciousness and sleep. Sleeplessness is unnatural and in the play emerges due to unnatural deeds. Sleeplessness also furthers the idea that unnatural acts of an individual harm him and destroy the balance of nature. Macbeth is a tragedy and tragedy involves the downfall of characters basically moral due to their tragic flaws. In Macbeth sleeplessness of Macbeth and Lady Macbeth is the evidence of deep rooted, torturous, and self-destroying guilt and fear. Guilt only emerges in characters who are basically moral and so their guilty act or crime becomes a point of tragedy. A workable thesis statement on this theme can thus be that, Shakespeare uses affliction of sleeplessness on Macbeth and Lady Macbeth to show the magnitude of their crime against their own natures thereby keeping alive their basic morality.