Water fills up all the empty places on the earth and clings fast to it. The social organization of ancient China was based on this principle of the holding together of dependents and rulers. Water flows to unite with water, because all parts of it are subject to the same laws. So too should human society hold together through a community of interests that allows each individual to feel himself a member of a whole. The central power of a social organization must see to it that every member finds that his true interest lies in holding together with it, as was the case in the paternal relationship between king and vassals in ancient China.