李筌 Li Chʽüan of the 8th century was a well-known writer on military tactics. His 太白陰經 has been in constant use down to the present day. The 通志 mentions 閫外春秋 ( lives of famous generals from the Chou to the Tʽang dynasty ) as written by him. 100 He is also generally supposed to be the real author of the popular Taoist tract, the 陰符經 . According to Chʽao Kung-wu and the Tʽien-i-ko