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