The Mencius (also spelled Mengzi or Meng-tzu), a book of his conversations with kings of the time, is one of the Four Books that Zhu Xi grouped as the core of orthodox Neo-Confucian thought. In contrast to the sayings of Confucius, which are short and self-contained, the Mencius consists of long dialogues, including arguments, with extensive prose. It was generally neglected by the Jesuit missionaries who first translated the Confucian canon into Latin and other European languages, as they felt that the Neo-Confucian school largely consisted of Buddhist and Taoist contamination of Confucianism. Matteo Ricci also particularly disliked Mencius's strong condemnation of celibacy as unfilial. François Noël, who felt that Zhu's ideas represented a natural and native development of Confucius's thought, was the first to publish a full edition of the Mencius at Prague in 1711; as the Chinese rites controversy had been recently decided against the Jesuits, however, his edition attained little influence outside central and eastern Europe.

One of Mencius's direct descendants was Dr. Meng Chih (Anglicised as Dr. Paul Chih Meng) former Director of China House, and Director of the China Institute in 1944. Time magazine reported Dr. Meng's age that year as 44. Dr. Meng died in Arizona in 1990 at the age of 90. North Carolina's Davidson College and Columbia University were his alma mater. He was attending a speech along with Confucius descendant H. H. Kung.

In 1978 book purporting to estimate the hundred most influential persons in history to that point, Mencius is ranked at 92.

While Confucius himself did not explicitly focus on the subject of human nature, Mencius asserted the innate goodness of the individual, believing that it was society's influence – its lack of a positive cultivating influence – that caused bad moral character. "He who exerts his mind to the utmost knows his nature" and "the way of learning is none other than finding the lost mind."