The T'ang dynasty astrologer Li Hsu-chung, credited with first incorporating the hour of birth and thus establishing the Eight Cyclical Characters divination system, makes the following philosophical statement in his work Li Hsu-chung Ming-shu: "For those who step outside the Five Elements, life and death is in their own hands."
傳說首先用一個人誕生的年、月、日來批命的唐朝李虛中，雖然自己精究命理，卻也在他的著作「李虛中命書」中，留下一句充滿哲理的話：「出五行之外者，生死在乎我；居清濁之內者，存亡從數焉。」