Han Fei was a legalist philosopher and essayist in the 3rd century during the Warring States Period. His legalist thought had provided important theoretical support for the rule of the later Qin dynasty, China's first centralized state.

Han Fei was a prince of the royal family of the State of Han. He stuttered and could not present his ideas in court, which was a serious impediment. But he overcame this by developing one of the most brilliant writing styles in ancient China.

Han Fei saw the gradual, but constant, decline of the state of Han and tried on several occasions to persuade the king to change policies to develop the agriculture and strengthen military force. But the king proved incapable of following his advice. In despair, Han Fei put down his political thinking in essays, hoping in vain that these essays would awaken the King.

Ultimately, Han Fei's works made their way to the state of Qin where the future Emperor Qinshihuang saw them and
wanted to meet the man who wrote them. Han Fei came to Qin in 234. He and Chancellor of Qin, Li Si had both studied with the philosopher Xun Kuang. Feeling he was not the equal of Han Fei, Li Si frame something on Han Fei, who then was put to prison and later poisoned by Emperor Qinshihuang. 

When he died in 233, Han Fei was still a young man, but he had already established a reputation because of his brilliant writings. Some 55 of his books survive collected together in the Hanfeizi. Among the most famous of them are "Five Vermin" which castigates the rulers of the day for pandering to useless people like Mohist and Confucian scholars and knights-errant who disrupt the court and weaken the country.

|Philosophers of the time of Han Fei were all advocating rulers to return to the past and learn the way their ancestors run the state. Han Fei was firmly against this. He advocates to govern the state in consideration of the present circumstances. He was also against rule the state with benevolence which the Confucious scholars persuade the rulers to do. He holds fat awards to those worth it and severe punishment to crimes, along with an emphasis on developing agriculture and military force were the four guarantee for successful rule and a strong state.    

His philosophy has exerted a far-reaching influence over the centralized rules of the feudal dynasties.