How through legalism did the qin establish unity in china and why was it unable to last?

Answer 1

Mainly utilizing philosophy of Legalism as general guide, Qin established a system of laws to control and maintain the empire. It was a very effective system during war times, but as war ended, some of the laws were regarded as too harsh. Also, lack of effective enforcement on a nation-wide scale was a problem.

The Qin empire conquered a vast geographical area within a very short period of time, there was not enough time to establish a proper bureaucracy to control with the added population.

Through Qin dynasty fell merely 15 years after its inception, the problem is not with Legalism.When Emperor Qin was alive, he had the support of his generals and the military, and was in general able to control his vast Empire. But his successor was a terrible ruler, and the military was divided by political struggles in court, the weakened central government gave insurgents opportunity to overthrow the government.

Many of Legalism's philosophies are incorporated into Imperial system, it is say later rulers rule in appearance by Confucianism and in essence through Legalism.