section_path: Reign as Emperor of Qin/Philosophy
section_name: Philosophy
paragraph_text: Philosophy
  
  While the previous Warring States era was one of constant warfare, it was also considered the golden age of free thought. Qin Shi Huang eliminated the Hundred Schools of Thought, which included Confucianism and other philosophies. With all other philosophies banned, Legalism became the mandatory ideology of the Qin dynasty.
  
  Beginning in 213 BC, at the instigation of Li Si and to avoid scholars' comparisons of his reign with the past, Qin Shi Huang ordered most existing books to be burned, with the exception of those on astrology, agriculture, medicine, divination, and the history of the state of Qin. This would also serve to further the ongoing reformation of the writing system by removing examples of obsolete scripts. Owning the Classic of Poetry or the Book of Documents was to be punished especially severely. According to the later Shiji, the following year Qin Shi Huang had some 460 scholars buried alive for possessing the forbidden books. The emperor's oldest son Fusu criticised him for this act. The emperor's own library did retain copies of the forbidden books, but most of these were destroyed when Xiang Yu burned the palaces of Xianyang in 206 BC.
  
  Recent research suggests that this "burying Confucian scholars alive" is a Confucian martyrs' legend. More probably, the emperor ordered the execution of a group of alchemists who had deceived him. In the subsequent Han dynasty, the Confucian scholars, who had served the Qin loyally, used this incident to distance themselves from the failed regime. Kong Anguo (c. 165 – c. 74 BC), a descendant of Confucius, described the alchemists as Confucianists and entwined the martyrs' legend with his story of discovering the lost Confucian books behind a demolished wall in his ancestral house.
  
  Qin Shi Huang also followed the theory of the five elements: fire, water, earth, wood, and metal. It was believed that the royal house of the previous Zhou dynasty had ruled by the power of fire, associated with the colour red. The new Qin dynasty must be ruled by the next element on the list, which is water, Zhao Zheng's birth element. Water was represented by the colour black, and black became the preferred colour for Qin garments, flags, and pennants. Other associations include north as the cardinal direction, the winter season and the number six. Tallies and official hats were 15 centimetres (5.9 inches) long, carriages two metres (6.6 feet) wide, one pace (步; bù) was 1.4 m (4.6 ft).