Āyatana (Pāli; Sanskrit: आयतन) is a Buddhist term that has been translated as "sense base", "sense-media" or "sense sphere". In Buddhism, there are six internal sense bases (Pali: ajjhattikāni āyatanāni; also known as, "organs", "gates", "doors", "powers" or "roots") and six external sense bases (bāhirāni āyatanāni or "sense objects"; also known as vishaya or "domains").
There are six internal-external (organ-object) (Pāli; Skt. ), pairs of sense bases:
eye and visible objects
ear and sound
nose and odor
tongue and taste
body and touch
mind and mental objects
Buddhism and other Indian epistemologies identify six "senses" as opposed to the Western identification of five. In Buddhism, "mind" denotes an internal sense organ which interacts with sense objects that include sense impressions, feelings, perceptions and volition.
In the Four Noble Truths, the Buddha identifies that the origin of suffering (Pali, Skt.: dukkha) is craving (Pali: ; Skt.: ). In the chain of Dependent Origination, the Buddha identifies that craving arises from sensations that result from contact at the six sense bases (see Figure 2 below). Therefore, to overcome craving and its resultant suffering, one should develop restraint of and insight into the sense bases.
Throughout the Pali Canon, the sense bases are referenced in hundreds of discourses. In these diverse discourses, the sense bases are contextualized in different ways including:
Sextets (Pali: chakka):The sense bases include two sets of six: six sense organs (or internal sense bases) and six sense objects (or external sense bases). Based on these six pairs of sense bases, a number of mental factors arise. Thus, for instance, when an ear and sound are present, the associated consciousness (Pali: ) arises. The arising of these three elements (dhātu) – ear, sound and ear-related consciousness – lead to what is known as "contact" (phassa) which in turn causes a pleasant or unpleasant or neutral "feeling" or "sensation" (vedanā) to arise. It is from such a feeling that "craving" () arises.