Mencius is the Latinized form for Mengzi (Meng Tzu), which means "Master Meng" in Chinese. He is revered as China’s Second Sage, surpassed only by Confucius. His personal name was Ke (K’o), and like Confucius he came from a lower aristocratic family.
Mencius’s mother was widowed, but she made sure that he grew up in a good environment. She is honored as a model mother, and he later showed her great devotion. Mencius studied under the disciple of a grandson of Confucius.
Like Confucius he traveled from state to state attempting to convince rulers to govern by virtue and follow the ways of ancient sage rulers, most often in vain; also like Confucius he was a distinguished teacher. He debated with other philosophers, most notably with Moists. He wrote a book entitled The Mencius, which contains his sayings and teachings.
Mencius expounded on Confucian teachings on government and human nature. He emphasized the quality called ren (jen), which means "humanity" and "love", but unlike the Moists who insisted on universal love, or the obligation to love all equally, Mencius insisted that one’s love to others is graded depending on their mutual relationships and obligations.
Mencius also insisted on the practice of righteousness, a sense of duty, or yi (i), in human relations. He argued that it was the practice of these virtues that had made the reigns of ancient rulers a golden age.
Mencius lectured about benevolent government, insisting that the government existed for the people, not vice versa. But if the ruler neglected his responsibilities, or worse if he misruled his people, Mencius was more radical than Confucius, saying that such a ruler has forfeited the Mandate of Heaven and should be overthrown.
He further explained that while the ruler owed the people a moral example, he could not expect them to practice virtue without enjoying economic well-being. Thus he advocated and explained various social and economic programs that would be in the enlightened self-interest of rulers to provide.
He idealized the early Zhou dynasty for implementing the well-field system, one that divided the land equitably for groups of eight farming families that jointly farmed a ninth plot for the government and argued for its restoration.
Mencius taught that all people are born with the beginnings of virtue and inclination to goodness, which is as natural as water’s inclination to flow downward. People turn to evil when they neglect to cultivate their innate goodness.
Thus, self-cultivation, a moral education, and the study of history are essential for individuals to return to purity, and the same applies to states to return to the virtuous ways of the golden age. These teachings have made Mencius loved by the people and feared by tyrants.