Moderator: Mahavihara moderator
Spk distinguishes the different types of “eyes” referred to in the canon. These are first divided into two general classes: the eye of knowledge (ñāṇacakkhu) and the physical eye (maṃsacakkhu). The former is fivefold: (i) the Buddha eye (buddhacakkhu), the knowledge of the inclinations and underlying tendencies of beings, and the knowledge of the degree of maturity of their spiritual faculties; (ii) the Dhamma eye (dhammacakkhu), the knowledge of the three lower paths and fruits; (iii) the universal eye (samantacakkhu ), the Buddha’s knowledge of omniscience; (iv) the divine eye (dibbacakkhu), the knowledge arisen by suffusion of light (which sees the passing away and rebirth of beings); and (v) the wisdom eye (paññācakkhu), the discernment of the Four Noble Truths. The physical eye is twofold: (i) the composite eye (sasambhāracakkhu), the physical eyeball; and (ii) the sensitive eye (pasādacakkhu), i.e., the sensitive substance in the visual apparatus that responds to forms (perhaps the retina and optic nerve). Here the Blessed One speaks of the sensitive eye as the “eye base.” The ear, etc., should be similarly understood. Mind (mano) is the mind of the three planes, which is the domain of exploration with insight (tebh̄makasammasanacāracitta).
For the commentarial treatment of the sense bases, see Vism 444–46 (Ppn 14:36–53). Hamilton challenges the commentarial classification of the first five sense bases under the rūpakkhandha, arguing from the fact that the standard definition of the form aggregate in the suttas does not include them. In her view, the sense faculties are powers of perception partaking of both material and mental characteristics and thus unclassifiable exclusively under rūpa (Identity and Experience, pp. 14–22). By the same logic, however, it might be argued that the five external sense bases should not be assigned to the rūpakkhandha, for again the suttas do not place them there. The plain fact is that the correlations between the khandhas, āyatanas, and dhātus are not made explicit in the Nikāyas at all, but only in the Abhidhamma Piṭaka, which classifies both the first five internal and external sense bases under rūpa. The five faculties and four sense objects (excluding the tactile object) are categorized as “derivative form” (up̄d̄ r̄pa), i.e., form derived from the four primary elements; the tactile object is classified under three of the primary elements: earth (hardness or softness), heat (hotness or coolness), and air (pressure and motion). The suttas themselves do not enumerate the types of derivative form, and the Abhidhamma texts seem to be filling in this lacuna.