Abstract
In Spring and Autumn Period the society was in turmoil. The Legalist claimed to seek quick success on richening the country and strengthening the army. So it gain mainstream status on political and law thought during the Warming States and Qin Dynasty. To the reign of Emperor Hanwu, with the Qin Dynasty’s fall, the Legalist lost the mainstream status. To analysis of reason, the lesson of Qin’s Dynasty’s fall, the practical social situation and the theoretical defects of the Legalist itself are all included. On the surface there are many defects on the legalism Ideology like harsh penal code, the ignorance of moral education and the strangle to people’s freedom . In fact, there are deeper defects such as the pessimistic to human natures, and quick benefits. These defects determine the legalist can’t last for long.
Key word: Legalist school; Mainstream; Government by law; Authority; Human nature
