On one occasion, Li Shimin and Wei Zhi discussed the way of governing the country. Li Shimin asked: What was the reason for the demise of the Sui Dynasty? Wei Zhi replied: Losing people's hearts. Li Shimin asked again: What should be the relationship between the people and the emperor? Wei Zhi said: The emperor is like a beautiful ship, and the people are the floods in Wang Yang. Big ships can only sail in the water; However, water can carry a boat and also overturn it. Emperor Tai Shang (Li Yuan) raised the banner of righteousness to overthrow the rule of the Sui Dynasty, which illustrates this point. Therefore, as a king, always remember that water can carry a boat and overturn it.