It is common for people to react harshly after committing murderous crimes. In other literary works, authors often show main characters losing their minds after committing heinous acts. For example, the main character of Edgar Allan Poe's A Telltale Heart is driven mad by the supposedly beating heart of the old man he murdered. Poe makes it clear that the man is definitely dead and his heartbeat is only heard by the main character. This is similar to Banquo's ghost, as it is only visible to Macbeth. This sight causes those around him to question his sanity, just as it caused the main character of A Telltale Heart to confess to a crime. In conclusion, Macbeth's criminal actions throughout the play inevitably led to his mental deterioration, similar to those in other parts of the play.