Eighteen Dhātus

Eighteen Dhātus : The eighteen dhatus function through the five aggregates. The eighteen dhatus can be arranged into six triads, where each triad is composed of a sense organ, a sense object and sense consciousness. In regards to the aggregates:

• The first five sense organs (eye, ear, nose, tongue, body) are derivates of form. The sixth sense organ (mind) is part of consciousness.

• The first five sense objects (visible forms, sound, smell, taste, touch) are also derivatives of form. The sixth sense object (mental object) includes form, sensation, perception and mental formations.

• The six sense consciousness are the basis for consciousness.

The dhātus grouped according to skandha

The Eighteen Dhātus

Six External Bases (bhāya-āyatana)	Six Internal Bases (adhyātma-āyatana)	Six Consciousness (vijñāna)
(1) Visual Objects (rūpa-āyatana)	(2) Eye Faculty (cakṣur-indriya-āyatana)	(3) Visual Consciousness (cakṣur-vijñāna)
(4) Auditory Objects (çabda-āyatana)	(5) Ear Faculty (śrota-indriya-āyatana)	(6) Aural Consciousness (śrota-vijñāna)
(7) Olfactory Objects (gandha-āyatana)	(8) Nose Faculty (ghrāṇa-indriya-āyatana)	(9) Olfactory Consciousness (ghrāṇa-vijñāna)
(10) Gustatory Objects (rasa-āyatana)	(11) Tongue Faculty (jihvā-indriya-āyatana)	(12) Gustatory Consciousness (jihvā-vijñāna)
(13) Tactile Objects (spraṣṭavya-āyatana)	(14) Body Faculty (kaya-indriya-āyatana)	(15) Touch Consciousness (kaya-vijñāna)
(16) Mental Objects (dharma-āyatana)	(17) Mental Faculty (mana-indriya-āyatana)	(18) Mental Objects (mano-vijñāna)

The table below briefly cites Buddhist primary sources that characterize different aspects of the aggregates. This table is by no means exhaustive.

Some references to the aggregates in Buddhist primary sources (Abbreviations: MN = Majjhima Nikaya; SN = Samyutta Nikaya; Vism = Visuddhimagga.)