While it is easy to view Frankenstein as a "horror" novel, the underlying message is actually social commentary on the effects of human prejudice and discrimination. The monster is an outcast of society because of his appearance. "Normal" human beings abhor his ugliness and, therefore, shun him. Even though the monster initially shows an ability to be friendly and loving, no one can see past his looks, so he never has a chance to fit in. After living in misery and loneliness for so long, the monster becomes angry at his position as a social outcast. He begins to feel justified in seeking revenge on those who have shunned him, especially his creator, Dr. Frankenstein. While there is no real justification for the monster's murderous rampage, we can understand his motive: he has endured the pain of prejudice long enough and must act out on his feelings of bitterness and anger.