Mencius was one of the great philosophers of ancient China second only in influence to Confucius whose teachings he defended & expanded The Mencius in which he recounts his dialogues with kings dukes & military men as well as other philosophers is one of the Four Books that make up the essential Confucian corpus It takes up Confucius's theories of jen or goodness & yi righteousness explaining that the individual can achieve harmony with mankind & the universe by perfecting his innate moral nature & acting with benevolence & justice Mencius' strikingly modern views on the duties of subjects & their rulers or the evils of war created a Confucian orthodoxy that has remained intact since the third century BCE