 Extension is necessary because natural compassion is uneven compared to where it ought to extend. King Xuan may find it natural to have compassion for an innocent man about to be executed or a terrified ox about to be slaughtered, but not toward all his subjects when he is focusing on the benefits that a war of territorial expansion might bring him. This story of Mencius, the King, and the ox is rich material for reflection on the nature of moral development. It seems plausible that development must begin with something that is of the right nature to be shaped into the moral virtues, and also plausible that what we begin with is not as it fully should be. The questions posed by the story is what the natural basis of morality is and how further development occurs. Mencius’s theory of the “four duan” addresses these questions. “Duan” literally means “tip of something” and is often translated as “beginnings” in this context. 