This refers to the various schools of thought and their proponents during the period from the late Spring and Autumn Period through the early Han Dynasty.The Spring and Autumn Period witnessed an increasing disintegration of the old social order as well as of the values of the Zhou Dynasty. Faced with a social crisis , scholars of the times  reflected deeply on problems, free from any restrictions. They advanced diverse theories on how to restore order and develop values. Such active theory-building and academic debating continued up to the early period of the Western Han Dynasty. Later generations referred to the large number of scholars and their works which had emerged at that time as A Hundred School of Thought (numerous philosophers and their works), and classified them into ten schools of thought: Confucianism, Mohism, Daoism, Logicians, Legalism, School of Yin-Yang, Agriculturalism, School of Diplomacy, Syncretism (or School of Miscellany, za jia), and School of Minor Talks (xiaoshuo jia). Among them, the first nine were more scholarly, and were therefore known as the "nine mainstream schools of the ten schools of thought." Due to the large number of proponents and their various theories, they are generally referred to as "A Hundred Schools of Thought."

Of the ten schools of thought, nine of them are worth learning about. The scholars of these schools all emerged during a time when benevolent governance was in decline and many rulers governed with military might. Some of the kings were benign rulers, while others were despotic. Scholars of the nine schools of thought eagerly made propositions in which they believed to kings to seek their endorsement and support.  (The History of the Han Dynasty)