  As their movement flourished in the 4th and 3rd centuries BCE, the Mohists branched into a number of groups, each led by a juzi, or grand master. Two early sources, the Hanfeizi (Book 50, ca. 233 BCE or later) and the Zhuangzi (Book 33, perhaps 2nd century BCE), mention a total of six groups of Mohists, who apparently quarreled among themselves over the details of Mohist doctrine. Another early text, the Lushi Chunqiu (ca. 239 BCE), mentions at least three other Mohist juzi. Evidence from the Mozi and Lushi Chunqiu indicates that these Mohist groups were disciplined organizations devoted to moral and practical education, political advocacy, government service, and in some cases military service. Members underwent a period of study and training, after which the organization might find them positions in government or the military, probably in a Mohist regiment. Members were expected to contribute funds to the organization and could be expelled for failing to fulfill their duties. The Mohists were renowned for fervent commitment to their ethical principles and to a lifestyle of austerity and self-sacrifice. A Han dynasty text collected in the Zhuangzi claims that many Mohists believed it was their duty to emulate the legendary altruistic labors of the ancient sage king Yu: