 When one speaks of the physical nature, it is like saying that the nature lies within the matter of qi (qizhi). This matter (zhi) is humanity’s material form (qizhi zhi xing), within the confines of which the principle of life (sheng zhi li) is manifested. Since it [i.e., the principle of life] lies within this matter, qi permeates it, and just as what fills the universe both inside and outside the human body is nothing but qi, so it is nothing but principle. Principle operates within qi, where it controls and apportions qi. Thus the matter [of individual things] envelops qi, and qi envelops principle. It is because this matter envelops qi that a given individual possesses a nature. For this reason, before one’s development has taken place, there can only be the li and qi of the universe but not the individual person. Once, however, there is the matter incorporating qi, this qi then inevitably possesses principle. As far as humanity is concerned…, this nature as found in the matter of qi [i.e., physical nature] is still the original nature. (quoted in McMorran 1975: 443)