How good or bad is a person’s life? How good or bad is a world? In this dissertation, I will attempt to answer these questions. Common-sense would dictate that if a person’s life would be extremely bad, then bringing her into existence is a bad thing. Not only is it bad for the person who lives it, but also, it is bad because it makes the world a worse place. A world populated only by individuals who have lives full of unrelenting misery and suffering is certainly worse than a world only populated by individuals who are extremely well off. If we can measure the value of a person’s life and the value of a world, then we can determine how good or bad our lives are and how good or bad the actual world is. Investigating these issues and ...