The Confucian thinker who argued that human nature is good — the great second teacher of the tradition, who built Confucius's ethics into a bold philosophy of innate goodness and drew from it a doctrine that a ruler who turns tyrant forfeits the right to rule and may be removed.
Mencius asked his listeners to picture a single moment. Any person who suddenly saw a small child about to fall into a well would feel a flash of alarm and pity. Not to win the parents' thanks, not to gain a good name, not from any plan at all. The feeling simply rises. From this one image he built his whole philosophy: human nature is good. Everyone is born with the seeds of compassion and justice, which only need cultivating to grow. And he drew a sharp political edge from it. A ruler who starves and brutalizes his people betrays that goodness and ceases to be a true king. Punishing such a man, Mencius said of an ancient tyrant, was not killing a true king. It is cutting down a mere fellow. That argument made him, for two thousand years, one of the most politically dangerous thinkers in the Confucian canon.