 Choi Young-jin (2011: 9) describes this as “a state of moderation […] bent neither one way or another […] the state of balance”. This actual state of mind had never been analysed in such minute detail before, nor had it been considered in such detail in relation to the sage, normal humans, and other animals: were they the same, or not, at the microcosmic level of their mind in terms of ki or Principle? Han Wŏn-jin’s essay on the “Explanation of the Original Nature and the Psycho-Physical Nature”, sowed the seeds of the debate. In this essay he suggested that the original nature, even before being aroused in the mind (mibal, as argued by T’oegye), was already interacting with ki, in other words, energised by material force, or as Richard Kim (2017: 92) puts it, Han viewed “gi [ki] as constitutive of the inactivated mind”. For Han, Principle required ki, so ki already had to exist in the mind and this ki had to be originally good or in equilibrium, balanced and unmotivated by desires. Clearly Han was “adhering more strictly to the materialist core of the ki school”, while claiming that “nature is not an abstract [undifferentiated] entity”, and that Principle “is nothing but a law of the dynamics of ki,” in other words, Principle had no concrete existence of any sort (Seoh 1977: 48). He ultimately saw the nature of a human and other animals as different even in their unaroused or mibal state where ki was inactive, and used their different psycho-physical make-up (due to the variant manifestations of material force when activated) as the basis for his thesis. Han ultimately considered the sage to possess a pure form of ki, already balanced and pure even in an unaroused state, unlike other beings (which for him also included women and children) and in this sense he is more hierarchically inclined in his approach, with a more idealistic vision of the sage—something usually linked with proponents of Principle.