The pre-Ch'in philosopher Kuan Tzu wrote: "The essence of all creation descends into the earth to become the five grains, and rises to form the stars in the sky; when it roams midway between the earth and sky we call it ghosts and spirits, and when it lodges in the breast of a man we call him a Sage.
「管子」說：「凡物之精，比則為主，下生五穀，上為列星，流於天地之間，謂之鬼神；藏於胸中，謂之聖人，是故名氣。」還有像文天祥所說的那種「天地正氣」。