Among Kukai's esoteric teachings, in the Ben kenmitsu nikyoron he discussed the doctrine of the ten stages of mind as comprising nine exoteric stages with one superlative esoteric stage (kuken ichimitsu), while in his Jujushinron he taught that nine of the ten stages are superficially exoteric while all ten are ultimately identical with the highest esoteric stage (kuken jumitsu). Esoteric teachings can be understood from a holistic understanding of these seemingly contradictory teachings, and the uniqueness of Kukai's thought be known.
In this paper, I will pay special note to the term jisho (self-nature) and examine Kukai's unique conception of self-nature in his Hizo hoyaku, and establish its fundamental significance in his ten stages of mind theory.
First, I will discuss jisho in the ninth stage, which is considered to be an exoteric stage, and then the utterly different conceptual framework pertaining to jisho in the following tenth esoteric stage. This jisho has a profound connection with bodhicitta, and the difference in how bodhicitta is understood is relevant to how the theories of kuken ichimitsu and kuken jumitsu were established.
Kukai's affirmative understanding of jisho is foundational to his ten stages of mind theory, and proved to be the most important motive force in the establishment of the esoteric doctrines.
