 Fang shi practiced medicine and divination and claimed to possess secret texts and formulae. They gained great influence during the earlier part of the Han dynasty, though their influence waned by the later Han. The fang shi used yin-yang and Five Agents cosmology. They seem to have originated from the Shandong peninsula, and were particularly associated with the mantic arts, including the use of the sexagenary cycle of stems and branches, the Yi jing, and divination by stars, dreams, physiognomy, the winds, and by the use of pitch pipes (Ngo 1976).