翻譯名義集 6.42

6.42

[Dhātu]
Here translated as "realm" (界, dhātu). The Baifa shu says: "'Realm' has the meaning of 'cause'. The six intermediate consciousnesses are produced in reliance upon the six sense faculties. The six sense fields induce their arising and serve as causes for the consciousnesses; therefore they are called 'realms'." The Fajie cidi says: "'Realm' takes 'distinction' (界別) as its meaning. These eighteen phenomena each have their distinct essence without confusion; hence they are named the 'eighteen realms'. When faculties and objects face one another, consciousness is produced. Consciousness takes 'discernment' (識別) as its meaning. Relying on the faculties, consciousness can discern the dust-like sense fields; thus they are collectively named consciousnesses. Because these three—faculties, dust-fields, and consciousnesses—each comprise six phenomena, they form the eighteen realms."
These three categories of phenomena are as stated in the Kośa: "Accumulation, gates of arising, and lineage / Are the meanings of aggregates, bases, and realms; / Because deluded views, faculties, and inclinations are threefold, / The aggregates, bases, and realms are taught accordingly." The commentary explains: "The three types of delusion are: first, delusion regarding mind, for which the five aggregates are taught, unfolding the mind into four and combining form into one; second, delusion regarding form, for which the twelve bases are taught, unfolding form into ten and a half bases—namely the five faculties, the five fields, and a subtle fraction of the mental-object field—and combining mind into one and a half bases, namely the mental faculty and a subtle fraction of the mental-object field; third, delusion regarding both mind and form, for which the eighteen realms are taught, further unfolding mind into seven and a half realms—namely the six consciousnesses, the mental faculty, and a subtle fraction of the mental-object field." 'Delusion' in all these cases means confusion. The three faculties refer to superior, middling, and inferior faculties. The three inclinations refer to brief, middling, and extensive [expositions]. They correspond in turn to the three categories of phenomena.