Yi (义) means acting appropriately and doing things properly. The expression comes from The Book of Rites. It not only defines yi, but also refers to an important principle of state and social governance, that is, humans and all living things must act appropriately in line with the actual circumstances, to suit both the time and the individual. At the highest level, it means that all living things must follow their intrinsic nature to grow and become their best. It is an idea of governance that integrates the man-made and the natural, and also a view of responsibility and justice that is both necessary and inevitable.