What reason does Zhou give for the loss of the mandate?

Zhou argues that the loss of the mandate is primarily due to the failure of rulers to govern justly and effectively. When leaders become corrupt, oppressive, or disconnected from the needs of the people, they forfeit their right to rule. This shift in power reflects the belief that legitimacy is granted by the people's support, and once that support is lost, the mandate is revoked. Thus, moral integrity and the welfare of the populace are central to maintaining the mandate.