After experiencing a cruel ban in the short-lived Qin Dynasty，Confucianism was proclaimed the national curriculum and became a requirement for the application for a government post in the Han Dynasty.The end of the Han was followed by a period of nearly 400 years of constant wars and chaos，during which period bitter physical and mental sufferings of the masses promoted the flourish of religious Buddhism，which was said to enter China at theend of the Eastern Han.In the Tang Dynasty，Confucianism again became an official philosophy due to its suitability to the needs of a centralized empire.Consequently，an Imperial Examination based on Confucianism was set up，aiming to choose talents to serve in state government.It was inevitable that there would be a revival of Confucianism.Confucianism finally reached maturity during the Song Dynasty，during which period classical Confucian texts were re-elucidated by many famous scholars.Such an evolvement of classical Confucianism later was tagged as Neo-Confucianism for its difference from the classical Confucianism.
Neo-Confucianism falls into two schools:School of Li and School of Xin.
·The School of Li
The School of Li or the School of Cosmic
Principle，was founded by Cheng Yi（1033-1107）and perfected by Zhu Xi（1130-1200）.Though challenged by many scholars of the day，Zhu Xi was the most influential Chinese philosopher from Mencius until the eve of the introduction of Western philosophy at the beginning of 20th century.Zhu’s philosophy is mainly collected in An Annotated Edition of Four Confucian Books，Collected Works of Zhu Xi and Classified Conversations of Master Zhu.
The School of Li divides universal being into Li and Qi to explain its birth.Zhu said，”In the universe，there are both Li and Qi.Li is metaphysical and the root of everything in the physical world；Qi is physical，referring to the matter which forms the physical beings.7Zhu held that everything in the universe，both natural and man-made，had its own Li，which is metaphysically independent and eternal.For Zhu Xi，in addition to the particular Li existing in each individual being which governs its formation，there is also an ultimate Li or cosmic principle called Taiji which governs the birth of the universe and exists in everything in the universe.8 Thus it also penetrates into each individual Li.Zhu analogized，“It is like the moon in the sky，which，though only one，can shed light vastly on universal beings.”
Philosophers of this school believe that universal beings of the same type share the same Li，and what makes them distinctive is the Qi they are made from.As far as human beings areconcerned，if you are more virtuous than I，then your Qi is less turbid than mine.Various degrees of clarity of Qi result in various universal beings.Such an idea also explains the root of human evil.As to individual cultivation and improvement，Zhu Xi advocated a principle of“Gewu Zhizhi”，which means the acquisition of the eternal principles of the universe by way of studying natural phenomena.He also emphasized a concept of“Jing” in this process.“Jing，”literally respectfulness，means being whole-hearted in doing things without being distracted from unrelated things.If an individual studies nature devotedly，he is sure to have a good chance of developing a profound insight into the ultimate principle of the universe，and then improving himself spiritually.