The term means the primal source from which all things originate, both animate and inanimate, including human beings. Yuan (元) manifests itself in different forms. In the Han Dynasty, it was considered a kind of primal physical material that both produced and made up the myriad things of the world. The Book of Changes divides yuan into two primal sources: the heavenly source which gives birth to the sun, moon, and stars, and the earthly source which creates all other things on earth. In The Spring and Autumn Annals, the term refers to the first year in its chronologies, symbolizing the start of a new historical period, and serving as the manifestation in the human world of the natural process in which things begin, end, and are replaced.
Yuan is a vital force, without shape in the beginning. It then takes on form to create both heaven and earth, and is the source of all their transformations. (He Xiu: Annotations on Gongyang’s Commentary on The Spring and Autumn Annals)
Great is the qian hexagram! All things owe their existence to it, and it guides the movement of heaven and creates its impact. (The Book of Changes)
Why does The Spring and Autumn Annals give such importance to yuan? This is because yuan is the primordial source of all things. (Dong Zhongshu: Luxuriant Gems of The Spring and Autumn Annals)