How was neo-confucianism different from confucianism

Neo-Confucianism was essentially a response by the Confucians to the dominance of the Daoists and Buddhists. Neo-Confucians such as Zhu Xi recognized that the Confucian system of the time did not include a thoroughgoing metaphysical system and so devised one. There were of course many competing views within the Neo-Confucian community, but overall, a system emerged that resembled both Buddhist and Daoist thought of the time and some of the ideas expressed in the Book of Changes (I Ching) as well as other yin yang theories associated with the Taiji symbol (Taijitu). A well known Neo-Confucian motif is paintings of Confucius, Buddha, and Lao Tzu all drinking out of the same vinegar jar, paintings associated with the slogan "The three teachings are one!"

While Neo-Confucianism incorporated Buddhist and Taoist ideas, many Neo-Confucianists claimed to strongly oppose Buddhism and Taoism. One of Han Yu's most famous essays decries the worship of Buddhist relics. Zhu Xi in particular, wrote many essays attempting to explain how his ideas were not Buddhist or Taoist, and included some extremely heated denunciations of Buddhism and Taoism.