Indriya

Indriya (literally "belonging to or agreeable to Indra") is the Sanskrit and Pali term for physical strength or ability in general, and for the senses more specifically. In Buddhism, the term refers to multiple intrapsychic processes and is generally translated as "faculty" or, in specific contexts, as "spiritual faculty" or "controlling principle." The term literally means "belonging to Indra," chief deity in the Rig Veda and lord of the Trāyastriṃśa heaven (also known as Śakra or Sakka in Buddhism) hence connoting supremacy, dominance and control, attested in the general meaning of "power, strength" from the Rig Veda.

In Buddhism, depending on the context, indriya traditionally refers to one of the following groups of faculties:

In the Pali Canon's Sutta Pitaka, indriya is frequently encountered in the context of the "five spiritual faculties" (Pali: pañc' indriyāni):

Together, this set of five faculties is one of the seven sets of qualities lauded by the Buddha as conducive to Enlightenment.

SN 48.10 is one of several discourses that characterizes these spiritual faculties in the following manner:

In SN 48.51, the Buddha declares that, of these five faculties, wisdom is the "chief" (agga).

In AN 6.55, the Buddha counsels a discouraged monk, Sona, to balance or "tune" his spiritual faculties as one would a musical instrument:

Relatedly, the Visuddhimagga and other post-canonical Pali commentaries caution against one spiritual faculty overpowering and inhibiting the other four faculties, and thus generally recommend modifying the overpowering faculty with the investigation of states (see dhamma vicaya) or the development of tranquillity (samatha). Moreover, these commentaries especially recommend that the five spiritual faculties be developed in counterbalancing dyads:

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