Mencius, also known by his birth name Meng Ke, was from Zou County (present-day southeastern Zoucheng City of Shandong) of the Warring States Period. He was a follower of Confucius’ thoughts and respected as "the Second Sage" by later generations.

Mencius was a pupil of Zisi and he traveled across various states like Qi, Wei, Teng and Song etc on learning tours. At one time, he served as an official under King Xuan in the State of Qi. Due to different opinions with King Xuan of Qi, Mencius returned to Zou County and concentrated on studies.

Based on "the policy of benevolence" and "ruling country with virtue" in Confucianism, Mencius advocated that in the constitution of a state, "the people rank the highest, the land and grain comes next, and the ruler counts the least". He held that all people were innately good and education should be adequately used to promote the civilization of society and he called for the improvement of relations between the emperor and his people within a certain limit.

Mencius' main book is The Mencius, which he composed with his disciples Wan Zhang and Gongsun Chou etc in his later years.