Sutta Piṭaka: mental hindrances

In the Pali Canon's Sutta Piṭaka, kilesa and its correlate upakkilesa^[1] are affective obstacles to the pursuit of direct knowledge (abhijñā) and wisdom (pañña).

For instance, the Samyutta Nikaya includes a collection of ten discourses (SN 27, Kilesa-saṃyutta) that state that any association of "desire-passion" (chanda-rāgo) with the body or mind^[2] is a "defilement of mind" (cittasse'so upakkileso):

"Monks, any desire-passion with regard to the eye is a defilement of the mind. Any desire-passion with regard to the ear... the nose... the tongue... the body... the intellect is a defilement of the mind. When, with regard to these six bases, the defilements of awareness are abandoned, then the mind is inclined to renunciation. The mind fostered by renunciation feels malleable for the direct knowing of those qualities worth realizing."^[3]

More broadly, the five hindrances – sensual desire (kāmacchanda), anger (byāpāda), sloth-torpor (thīna-middha), restlessness-worry (uddhacca-kukkucca), and doubt (vicikicchā) – are frequently associated with kilesa in the following (or a similar) manner:

Additionally, in the Khuddaka Nikaya's Niddesa, kilesa is identified as a component of or synonymous with craving (taṇhā) and lust (rāga).^[6]

Abhidhamma: ten defilements and unwholesome roots

While the Sutta Pitaka does not offer a list of kilesa, the Abhidhamma Pitaka's Dhammasangani (Dhs. 1229ff.) and Vibhanga (Vbh. XII) as well as in the post-canonical Visuddhimagga (Vsm. XXII 49, 65) enumerate ten defilements (dasa kilesa-vatthūni) as follows:

1. greed (lobha)
2. hate (dosa)
3. delusion (moha)
4. conceit (māna)
5. wrong views (micchāditthi)
6. doubt (vicikicchā)
7. torpor (thīnaṃ)
8. restlessness (uddhaccaṃ)
9. shamelessness (ahirikaṃ)
10. recklessness (anottappaṃ)^[7]

The Vibhanga also includes an eightfold list (aṭṭha kilesa-vatthūni) composed of the first eight of the above ten.^[8]

Throughout Pali literature, the first three kilesa in the above tenfold Abhidhamma list (lobha dosa moha) are known as the "unwholesome roots" (akusala-mūla or the root of akusala); and, their opposites (alobha adosa amoha) are the three "wholesome roots" (kusala-mūla or the root of kusala).^[9] The presence of such a wholesome or unwholesome root during a mental, verbal or bodily action conditions future states of consciousness and associated mental factors (see Karma).^[10]

Visuddhimagga: round of defilements

The 5th-century CE commentarial Visuddhimagga, in its discussion of "Dependent Origination" (Pali: paticca-samuppada) (Vsm. XVII), presents different expository methods for understanding this teaching's twelve factors (nidana). One method (Vsm. XVII, 298) divides the twelve factors into three "rounds" (vaṭṭa):

• the "round of defilements" (kilesa-vaṭṭa)
• the "round of kamma" (kamma-vaṭṭa)
• the "round of results" (vipāka-vaṭṭa).^[12][13]

In this framework (see Figure to the right, starting from the bottom of the Figure), kilesa ("ignorance") conditions kamma ("formations") which conditions results ("consciousness" through "feelings") which in turn condition kilesa ("craving" and "clinging") which condition kamma ("becoming") and so on.^[11] Buddhaghosa (Vsm. XVII, 298) concludes:

So this Wheel of Becoming, having a triple round with these three rounds, should be understood to spin, revolving again and again, forever; for the conditions are not cut off as long as the round of defilements is not cut off.^[12]

As can be seen, in this framework, the round of defilements consists of:

• ignorance (avijjā)
• craving (taṇhā)
• clinging (ūpādānā).^[12]

Elsewhere in the Visuddhimagga (Vsm. XXII, 88), in the context of the four noble persons (ariya-puggala, see Four stages of enlightenment), the text refers to a precursor to the attainment of nibbana as being the complete eradication of "the defilements that are the root of the round" (vaṭṭa-mūla-kilesā).^[14]

Three poisons

The three kleshas of ignorance, attachment and aversion are referred to as the three poisons (Skt. triviṣa) in the Mahayana tradition and as the three unwholesome roots (Pāli, akusala-mūla; Skt. akuśala-mūla ) in the Theravada tradition. These three poisons (or unwholesome roots) are considered to be the root of all the other kleshas.

Five poisons

In the Mahayana tradition, the five main kleshas are referred to as the five poisons (Sanskrit: pañca kleśaviṣa; Tibetan-Wylie: dug lnga).

The five poisons consist of the three poisons with two additional poisons: pride and jealousy. Altogether, the five poisons are:^[15][16]

Six root kleshas of the Abhidharma

The Abhidharma-kośa identifies six root kleshas (mūlakleśa):

• Attachment (raga)
• Anger (pratigha)
• Ignorance (avidya)
• Pride/Conceit (māna)
• Doubt (vicikitsa)
• Wrong view/False view/Opinionatedness (dṛiṣṭi)^[17]

In the context of the Yogācāra school of Buddhism, Muller (2004: p. 207) states that the Six Klesha arise due to the "...reification of an 'imagined self' (Sanskrit: satkāya-dṛṣṭi)".^[18]

Mahaparinirvana Sutra

The Mahayana Mahaparinirvana Sutra lists approximately 50 kleshas, including those of attachment, aversion, stupidity, jealousy, pride, heedlessness, haughtiness, ill-will, quarrelsomeness, wrong livelihood, deceit, consorting with immoral friends, attachment to pleasure, to sleep, to eating, and to yawning; delighting in excessive talking and uttering lies, as well as thoughts of harm.^{[citation needed]}

Two obscurations

Mahayana literature often features an enumeration of "two obscurations" (Wylie: sgrib gnyis), the "obscuration of conflicting emotions" (Sanskrit: kleśa-avaraṇa, Wylie: nyon-mongs-pa'i sgrib-ma) and the "obscuration concerning the knowable" (Sanskrit: jñeya-avaraṇa, Wylie: shes-bya'i sgrib-ma).^[19]