Ying Zheng had a large ambition to rule the land, he was not satisfy just be the king of Qin kingdom, so he keep conquered territories. During that time, there are six other coexisting kingdoms. The leader of each kingdom all proclaimed himself king. Every king wanted to achieve bigger power, have large territory, it depend whether they have the strength. So there always have small fights between kingdoms. Freud in his Civilization and Its Discontents stated, "The physically stronger man would decide them in the sense of his own interests and instinctual impulses'"(49). At that time, who was the stronger one, who could achieve bigger power, larger territories. Qin was the strongest kingdom. If they used their physical force to take over other
