Mencius (circa 372–289 BC), whose official name is Meng Ke, was a key Confucian figure in the Warring States Period. Mencius inherited and developed Confucius’s thought and became a Confucian master second only to Confucius. He has been regarded the Second Master to Confucius (Yasheng), and named together with Confucius as “Kong-Meng”.

He was born around one hundred years after the death of Confucius (479 BC). We have not much records of his early life, apart from a story in Biographies of Women of Chastity and Ardency (Lienu Zhuan), that his mother had to move three times in order to have a better growth environment for him. This story shows that her mother played a very important role in his education. According to Records of the Grand Historian, Mencius had studied trom a student of Zisi, Confucius’ grandson. This shows the academic lineage beiween Mencius and Confucius.

Like Confucius, Mencius had travelled to various states with his students to promote his ideals. He went to the states of Qi, Song, Wei, Lu, etc. He was eloquent in speech, a reputation which enabled him to attract hundreds of students. Every time he went to a place, he had always been received by the king. However, like Confucius, he failed to get the trust of the rulers, and went back to his hometown to teach in his later years.

Mencius inherited Confucius’s theory, and developed his ideal of benevolent rule. Confucius did not consider it a difficult task to govern a state. In his mind, as long as the rulers could cultivate themselves on morality, they could govern their states, and even the world well. Mencius further explained how a person’s good morality could be popularized as a common virtue in the process of “cultivation of himself” and “regulation of his family” to achieve “good governance under the heaven”. With everyone implementing the principle of “taking care of my parents and to extend the care to all the elderly in the world”, and of “taking care of my children and to extend the care to all children in the world”, benevolence would gradually prevail. This would be like the ripple effect of the water when one throws a stone into a pond. The waves would spread, eventually to the entirety of the pond.

Another of Mencius’s contribution was the theory of innate good nature, which was used to prove the psychological and physiological basis for the realization of moral promotion. Mencius believed that human nature was good when a person was born. The nature illustrates itself; for example, at a sight of a baby falling into a well, everyone, knowing the baby or not, would be holding their breath in terror. And this, in Mencius’s view, is the proof that the human nature is fundamentally good. On this basis, Mencius further asserted that all people have “four hearts” (or mind, or consciousness), namely compassion, shame, resignation, and right & wrong, which correspond with benevolence, righteousness, propriety and wisdom. To Mencius, moral cultivation is a necessity for everyone, physiologically and psychologically, just like all need to drink water and eat every day. On the one hand, a person’s good nature and “four hearts” determine his desire to be a good person and to cultivate himself; on the other hand, a person’s sense of right & wrong and shame enables him to know what is right and what is wrong, whom to learn from – most likely the good moral examples. With these two driving forces working in the background, the level of cultivation of the entire society would generally be raised, and the promotion of benevolence would not be difficult. Benevolent rule would naturally be in place, unlike a castle in the air.

Since people have “four hearts”, why are there so many unkind people and things in society? Mencius explained that that was because acquired desires obscured the good human nature. Mencius gave an example. The hill Niushan near the capital of Qi was bare. But had that always been the situation on Niushan? No. The hill was once full of trees. However, a lot of people went up the hill and chopped down trees, and now there is no more trees in the hill.

Human desires can hinder their good nature. Therefore Mencius emphasized the importance of self-cultivation. He elaborated on how to carry out self-cultivation in great detail, specifically, on how to cultivate one’s spirit, aspiration and self-character. In other words, he taught how to maintain one’s good nature in order to make himself a perfect man. Such teachings influenced the Confucian scholars, and have a strong impact on generations of Chinese.