In the turbulent Spring and Autumn Period (770-476BC) and Warring States Period (475-221BC), many schools of thought were flourishing. The four most influential schools of thought that evolved during this period were Confucianism, Taoism, Mohism, and Legalism. There were also other schools like Yin & Yang, Eclectics, Logicians, Coalition persuaders and Militarism. The hundred schools of thought showed the fierce political and class struggles for survival among regional wars between the rising landed class and slaveholder class. The flouring thoughts intensified activities and debates in the intellectual and ideology system in ancient China and exerted great influence on Chinese culture.

 Confucianism

Confucius was the founder of Confucianism. He advocated a set of moral code on basis of five merits: benevolence, righteousness, propriety, wisdom and trustworthiness. Among them, benevolence was considered as the cornerstone, which stands for faithfulness, filial piety, tolerance and kindness. He also requested people to keep in good harmony with each other and establish a community ruled by standard manners and behavior.

Mencius (372-289BC) was a Confucian in the Warring States Period (475-221BC). He repeatedly tried to convince rulers that the ruler should cultivate moral perfection in order to set a good example to the people and the ruler who governed benevolently would earn the respect of the people. He held the view that human nature was fundamentally good as everyone is born with the ability to recognize what is right and act upon it. He also believed that people were more important than rulers.

Xunzi (about 313-238BC), also a Confucian of the state of Chu, advocated the policy making a country rich and building up its military power, and sang high praise of the state of Qin.

 Mohism

The Mohism founded by Mozi flourished in the latter half of the fifth century. It resembles Confucianism in its reverence for humanism. Master Mo called for a universal love encompassing all human beings in equal degree. He suggested a harmonious relationship between people on a reciprocal basis. Thus he was an assertor of unionism who suggested a practice of a political relationship of mutual benefit or dependence between states.

 Taoism

The Taoism was founded by Laozi. The most important pre-Han Taoist bible was Laozi, also known as Dao De Jing (Classic of the Way and its Power). Laozi put forward a dialectic view: Good fortune follows upon disaster; Disaster lurks within good fortune. He tried to tell people not to exaggerate the importance of man too much because human life is only a small part of the universal and the only way can human actions make sense is to act in accord with the principles of the nature. It showed an integral concept of Taoism the withdrawal from the worldly affairs and the self-cultivation. Zhuangzi was a Taoist in the Warring States Period. He understood the Tao as the Way of Nature as a whole and the origin of the world. He believed that all things were in constant changes and there was no rule of right and wrong. In his mind, life was but a dream and only destruction could lead to the final peace of the society.

 Legalism

The Legalist School sought by every means possible to strengthen the state and increase its military might. It began to take shape late in the fourth century. Earlier legalists were Shang Yang, Li Kui  and Wu Qi. Later in the Warring States Period, the most important legalist named Han Fei advocated harsh rules and laws.

He was born in a rich family in the state of Han. In the book Han Fei Zi, he bent on organizing society on a rational basis and finding means to strengthen their states agriculturally and militarily. He also advised elaborate means for controlling people's lives and actions through laws and punishments. In his theories, law was the basis, strategies were the means in political struggle and power was the strength and high position. Only getting command of the three factors can a ruler establish a powerful state of central power. Han Fei's theory was applied by Qin and played an important role in unification of China by Qin Emperor Shihuang.