Answer: Legalism in ancient China was a philosophical belief that human beings are more inclined to do wrong than the right because they are motivated entirely by self-interest and required strict laws to control their impulses. It was developed by the philosopher Han Feizi (l. c. 280 - 233 BCE) of the state of Qin. It was he who actually implemented the ideas of the legalists across the growing Qin state. His most famous achievements included the construction of the Great Wall to protect the newly unified state from barbarian invaders and the creation of a universal system of writing.