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The Four Cankers (Āsavas)


T. H. Perera

Buddhist Publication Society
Kandy • Sri Lanka

Bodhi Leaves No. 35.

First Published: 1967

Digital Transcription Source: Buddhist Publication Society.

For free distribution. This work may be republished, reformatted, reprinted and redistributed in any medium. However, any such republication and redistribution is to be made available to the public on a free and unrestricted basis and translations and other derivative works are to be clearly marked as such and the Buddhist Publication Society is to be acknowledged as the original publisher.

The Four Cankers

“They who have given up passion, enmity,
And ignorance, the Arahants poison-purged,  [1]
I honour and revere, O Mātali.”

Saṃyutta Nikāya, Sakka Saṃyutta, XI, 2,9,

Honour to that Exalted One Arahant Buddha Supreme!

Lord Buddha, as recorded in the Mahā Saccaka Sutta, Majjhima, No. 36, realised in the last watch of the night: “These are the cankers … This the Arising of the cankers … This is the Ceasing of the cankers … This the Path leading to the Cessation of the cankers.“ Thus cognizing, thus perceiving, my mind was delivered from the canker of sensual craving; from the canker of craving for existence; from the canker of ignorance. Being delivered, I knew: “Delivered am I,” and I realised: “Rebirth is ended, fulfilled is the Holy life (brahmacariya), done what was to be done; there is none other life beyond this.”

This Sutta lists three cankers (āsava), namely: canker of

1. Sensual craving (kāmāsavā)

2. Craving for existence (bhavāsavā)

3. Ignorance (avijjāsavā)

Here, in craving for existence is also included the canker of False Views (diṭṭhāsava). “Being delivered” means the knowledge of gaining the Path (maggañāṇa-lābha), and “delivered” means the awareness of its fruition (phala-ñāṇa). This fact leads to two distinct divisions of Aryan Disciples, the Sekha and the Asekha. The former includes all those Disciples who have gained, through being trained in Morality (sīla), Concentration (samādhi) and Wisdom (paññā), the following Paths (magga) and Fruitions (phala) of Sainthood, namely, Stream-Winner (sotāpanna), Once-Returner (sakadāgāmi), Never-Returner (anāgāmi) and the Perfect One (Arahant) who has gained Path knowledge (magga-ñāṇa) only, in all seven Individuals. The term asekha includes all those Disciples who have completed the Aryan training by gaining the Fruition-Knowledge (phala-ñāṇa) of a Perfect One. These are the eight Individuals (or four pairs of Aryan Disciples) whom the Buddha speaks of in the Ratana Sutta:

“Those Eight Individuals, praised by the virtuous, constitute four pairs. They, the worthy of offerings, the Disciples of the Sugata, [2] gifts given to these yield abundant fruit. Verily, in the Sangha is this precious jewel. By this truth may there be happiness!”

None of us can ever hope to cut across the turbulent waters of the cosmic ocean of births and deaths, unless and until we have attained the status of these Eight Noble Individuals along with Nibbāna, often spoken of as the Nine Transcendental Dhammas (nava lokuttara dhamma). In the Mahā Maṅgala Sutta gratitude (kataññutā) is mentioned (among other things) as one of the Highest Blessings. Lord Buddha stands pre-eminent among all beings on whom we should bestow our reverential gratitude. The highest form of gratitude that we could confer upon him is to objectify Nibbāna by treading the Noble Eightfold Path. Arahantship is the crowning glory of the Noble Path. It should be noted here that Arahantship or Deliverance from Suffering is synonymous with Nibbāna, [3] and Arahantship is attained by the total destruction of the cankers (āsavas). I make this assertion on very good authority. At verse 93 of the Dhammapada, the Blessed One says:

Yassāsavā parikkhīṇā—āhāre ca anissito
Suññato animitto ca—vimokkho yassa gocaro
Ākāse’ va sakuntānaṃ—padaṃ tassa durannayaṃ.

’He whose cankers are destroyed, he who is not attached to food, he who has Deliverance, which is Void and Signless, as his object,—his path, like that of birds in the air, cannot be traced.’ [4]

For the benefit of most of us who are worldlings [5] intent on putting an end to this sorrow-laden process of being born, ageing and dying, I shall deal with the four types of cankers which we must, sooner or later, destroy to arrest the process of becoming (bhava). The four types of cankers are:

1. Canker of sensuality (kāmāsavā)

2. Canker of existence (bhavāsavā)

3 .Canker of false views (diṭṭhāsava)

4 .Canker of ignorance (avijjāsavā)

The Meaning of Canker

In simple language it is a malignant defilement of the mind that arrests its spiritual progress towards complete liberation. With respect to the spheres of existence (bhūmi), it extends up to the highest Brahma Realm, the sphere of neither-perception-nor-non-perception (n’eva saññā-nāsaññāyatana), and with respect to the mind-flux (santati) it prevails right up to Maturity-Knowledge (gotrabhū-ñāṇa). It oozes out, like water oozing out from tiny holes in a pot of water, through the unlocked doors of the six senses. In the manner of a man, who under the influence of liquor, loses his normal sense and commits various offences against society, even so under the influence of this poisonous drug (SN I 3, 3), man loses all sense of shame and fear, and acts in a manner detrimental to his own welfare as well as the welfare of others. In short, it lengthens saṃsāric existence with all the suffering inherent in it. The destruction of the cankers has to be done by one’s own efforts. Lord Buddha has shown the way to do it. Mere belief in a supernatural being and the false sense of security and salvation in that belief will never help; nor will matted hair or a tiger’s skin dress. The Blessed One very pithily puts it at verse 394 of the Dhammapada:

Kim te jaṭāhi dummedha?
Kim te ajinasāṭiyā?
Abbhantaraṃ te gahanaṃ
Bāhiraṃ parimajjasi?

’What avails thee of thy matted hair, O fool? What of the dress of tiger’s skin? Within thee is full of defilements, why cleanest thou the outside?’

1. The Canker of Sensuality (Kāmāsavā)

This means the desire for sensual pleasures. Sensuality is twofold: the desire to enjoy the delightful and pleasurable things found in the sentient sphere of existence and the objects that induce sensual enjoyment, namely: the desire for sights, the desire for sounds, the desire for smell, the desire for taste and the desire for tangibles. Beings intoxicated with the enjoyment of these sense objects, lose all sense of proportion and behave like lunatics, and chase after these sense objects to enjoy them ad libitum. Insatiate are their desires, now here, now there, seeking after more pleasures in pastures new. At the moment of death, their minds, stupefied with sense-desires, provide these sense-indulgers with a new mind-form in one of the four planes of woeful existence. While living on this plane, bereft of fear and shame, they feel no compunction whatsoever in transgressing the five precepts of non-killing, non-stealing, sexual purity, truthfulness and total abstinence from intoxicants.

The cause of sensuality is wrong thinking on an object that is sensually pleasant and agreeable. This object can be sensuality itself, or that which gives rise to sensuality. Wrong thinking on this sensuality-object is to take the impermanent as permanent; the ugly as beautiful; pain as pleasure; no-soul as soul. Sensuality is wiped out by right thinking, that is to consider the object as unwholesome and inauspicious. In the words of the Blessed One: “the condition for keeping out new sensuality and for casting out old sensuality is abundant right reflection on the sensuously inauspicious or unpromising object.” This is the task assigned to the jhānas (vivicceva kāmehi=detached from sense-desire). Wherefore, says the Blessed One: Develop the jhānas (absorptions), O Bhikkhus, and be not heedless! Do not direct your mind to sense-desires that you may not for your heedlessness have to swallow the iron ball in hell, and that you may not cry out when burning: “this is pain” (Dhammapada verse 371).

2. Canker of Existence (Bhavāsavā)

This is the desire for continued or eternal existence (bhava-taṇhā) either in the form-world or formless-world (rūpārūpaloka). This is so-called eternity belief of the theists who hold the belief in an eternal soul. in contradistinction to the eternity belief is the belief in self-annihilation (vibhava or uccheda-diṭṭhi), in which the soul is annihilated at death, and as a result there is no life after death. This is the doctrine maintained by the materialists. Lord Buddha rejected both these beliefs and taught the Middle Way, based on the natural law of cause and effect, or kamma, action-reaction. It must be clearly understood that kamma is the volitional act and its result or reaction (vipāka) follows the act. The principle involved is good begets good; bad or evil begets bad or evil.

Hence it is kamma that results in birth either in the form-world (rūpa-loka) or in the formless-world. A person who is dissatisfied with sense-desires, a really refined and holy person develops his mind (bhāvanā) to gain concentration (samatha or the jhānas). So long as he abides in the jhāna, he will experience a subtle and exhilarating sense of relief gained by total detachment from sense-desires. At death if he happens to be abiding in one of the four form-world jhānas, his dying consciousness will lead to birth in a form-world consonant with the jhāna he was abiding in at the moment of death. There is also the individual who finds no delight in Form-World existence, for he is convinced that suffering is due to this body of flesh and blood. Accordingly he objectifies a higher spiritual value and content. Based on the fourth form-world jhāna, he develops his mind to gain the formless-world spheres. At the moment of death, while still abiding in one of the four formless-world jhānas, he will be born in a Formless-Realm in keeping with the jhāna of his dying consciousness. This is the highest form of existence, where no trace of matter exists but only the mind. In both spheres of existence—form and formless—one may enjoy several kalpas of life, yet the fact remains, that one is liable to be born again in the sentient spheres and may also suffer in the states of woe. Therefore, intoxicated with the drug of eternal existence man is confined within the limits of Saṃsāra to continue the process of being born and dying. It is for this reason it is called a canker.

The Buddha-Dhamma does not at all value either type of existence. It goes beyond the cosmos, beyond conditioned existence. While accepting the jhānas as a sine qua non for further development of mind, it has bestowed upon man the priceless pearl, insight-wisdom (vipassanā-ñāṇa). In fact, vipassanā is a sole monopoly of Buddha-Dhamma. Wherefore, says the Blessed One at the Saṃyutta Nikāya (Devatā Saṃyutta, I 33):

“They that have lust and hate and nescience [6] spurned,
The Arahants, immune from deadly drugs. [7]
For them the tangle [8] all unravelled lies,
Where mind and body wholly cease to be,
And earthly sense and sense celestial;—
Here is the tangle riven utterly.”

3. The Canker of False View (Diṭṭhāsava)

The Brahmajāla Sutta or the Discourse on the Supreme Net (Dīgha Nikāya Sutta 1) gives us a list of 62 beliefs (diṭṭhi) current in the time of the Buddha. These beliefs are compared to a net in which beings are caught and made to run hither and thither and from which no escape is possible. Such is the fate of all mortals who are infected with the canker of false beliefs. There is, in this Sutta, a very interesting and illuminating passage which speaks of the beginning of theistic beliefs. Here, a person at the end of his jhānic existence in the world of Brahmā, is born on this earth. He leaves home for the homeless life and practises asceticism. At the height of a jhānic experience, he beholds the Brahma world from where he came, but, mind you, he does not see beyond. In a moment of ecstatic emotion, he rushes to the conclusion that, at the beginning, Heaven and earth and everything in it was the work of God, the Omnipotent, the Omniscient, the All-Seeing, the Lord of All, the Creator, the most High and Almighty Father of beings that are and are to be. This illustrates how various theistic beliefs have arisen, and, also explains the various inconsistencies and contradictions in regard to God and the Creation, in regard to his nature and intentions and in regard to man’s position in relation to God. All these divergent views are due to the fact that one attempts to expatiate on his limited experience in order to build up a concept of universality—the fallacy of part for the whole. This is the bane of conceptual ideas, which necessitates periodical revisions to harmonise and accommodate them in the light of the scientific knowledge. Truth is Truth; it is indivisible and cannot change. Lord Buddha speaks of himself as the Tathāgata. One of the interpretations of this multi-meaning word is: He practised what he preached and preached what he practised” (yathāvādī tathākārī yathākārī tathāvādī).

There is an attempt made by men of goodwill and understanding to harmonise and blend and bind together the truths in all faiths. It is a praiseworthy attempt in so far as it tends to arrest the growing malaise of irreligion, of religious fanaticism, of religious discrimination and the insidious attempt to proselytise the “heathen” to the true faith. But partial truths will never help anyone to gain total emancipation from suffering. No wonder that I heard, the other day, a distinguished Christian prelate, remarking that he believed in Kamma and the Noble Eightfold Path as the solution to man’s ills, but he advised his audience “to infuse the spirit of God” into its working! This “spirit of God,” this Soul, this Ego, this Divine Spark, this Eternal Entity forms the central core of all theistic faiths. It is chiefly because of this belief that Lord Buddha calls the third impediment to Sainthood the canker of false beliefs, upon which clings the eternity belief (sassata diṭṭhi) and the belief in annihilation (uccheda-diṭṭhi). In the Māra Saṃyutta, of the Saṃyutta Nikāya at IV, 2, 6, the Blessed One says:

“The body’s shape, [9] all that we feel, [10] perceive [11]
And know by sense [12] and whatso will hath planned [13]
This congeries—whoso doth know it well;
That’s is not I, that is not Mine—he thus
Breaks from its charm. Him thus dispassionate,
The self at peace, all fetters left behind,
Him, though they hunting seek in every sphere
Of life, the hosts of Māra ne’er will find.” [14]

Of all these diṭṭhis the most vicious, the most pernicious and the most inimical to spiritual progress is moral nihilism (natthika-vāda). One holder of this retrograde doctrine was a prince called Pāyāsi (DN 23) who propounded the following: 1. There is no life after death, i.e. no rebirth, 2. All beings are born through parents alone, there is no other source of birth, 3. There is no result (vipāka) of good or evil acts, in other words Kamma is a myth. Then there is another form of diṭṭhi known as confirmed or absolute scepticism (niyata-micchādiṭṭhi) which is the denial of all that is good, noble and pure in life—the heresy par excellence.

4. The Cankers of Ignorance

The Dhammapada at verses 242 and 243 illustrates very eloquently the taint of ignorance:

“Misconduct is the taint of a woman.
Stinginess is the taint of a donor.
Taints, indeed, are all evil things
both in this world and in the next.
A worse taint than these is ignorance, the greatest taint.
Abandoning this taint, be taintless, O Bhikkhus.”

(Transl. Nārada Thera)

The conspicuous characteristic of a taint is to corrupt or to infect or to eat into an object, be it physical or mental. In this sense the canker of ignorance eats into man’s moral fibre and debilitates his mind to such an extent as to make him consider evil as good; the unpleasant as pleasant; the impermanent as permanent; the unreal as real; soullessness as the soul and so forth, and thereby he succumbs to acts of cruelty, killing, stealing, sexual misconduct, lying etc., which, at death, condition a woeful existence in one of the four hells.

Deep and sober thinking on the quotation above, particularly verse 243 will convince you that the entirety of the Buddha-Dhamma is devoted to the task of eliminating ignorance (avijjā) or darkness and enthroning knowledge (vijjā) or light. You will agree with me that you and I have been and are being chained to the Wheel of Life (saṃsāra) “in a long running-on and faring-on both for me and for you” because of ignorance or darkness; until that glorious awakening when we, in the full glow of knowledge or light, shall penetrate the Four Noble Truths: this is Suffering; this is the Origin of Suffering; this is the Cessation of Suffering; this is the Path leading to the Cessation of Suffering, and thus put an end for ever to this sorrow-fraught process of being born, decaying and dying (saṃsāra-dukkha). Then and only then shall we make our final bow, our final farewell to saṃsāric existence or becoming

It is not my intention here to dilate on the causal nexus (paṭicca-samuppāda) or the wheel of life, in which ignorance (avijjā) is a basic condition for the coming into being of this mind-form flux. It is also by the total eradication of ignorance that the mind-form flux ceases to flow. I take it that every genuine Buddhist, who is interested in putting an end to this mind-form flux with its inherent suffering, has made it a daily routine practice to meditate on the causal nexus along with its twelve dependent conditions, for “who sees uprising by way of cause sees dhamma, who sees dhamma sees uprising by way of cause” (yo paṭiccasamuppādaṃ passati so dhammaṃ passati, yo dhammaṃ passati so paṭiccasamuppādaṃ passati).

Ignorance (avijjā) and delusion (moha) are taken as synonyms. To my mind, it appears that there is a subtle distinction between the two. The Pali word avijjā literally means not-knowing and moha literally means delusion. The former is the inability to know or see things as they really are, while the latter clouds an object and obscures mental vision. It is a mental state (cetasika) and is the parent of greed (lobha) and ill will (dosa). In the Saṃyutta Nikāya, Nibbāna is defined as the extinction of greed, ill will and delusion (rāgakkhayo dosakkhayo mohakkhayo idaṃ vuccati Nibbānaṃ). Wisdom is the very opposite of ignorance. It is wisdom (transcendental wisdom) that eliminates ignorance and leads to the realisation of the Four Noble Truths. In the Dhammacakkappavattana Sutta (Vinaya Mahāvagga and Saṃyutta Nikāya), Lord Buddha concludes His inaugural address to the five Bhikkhus of Isipatana with these words pregnant with the joy of Deliverance: “and there arose in me the knowledge (ñāṇa) and insight (dassana)—unshakable is the deliverance of mind, this is my last birth, and now there is no existence again.” It is crystal clear that these two attainments, “knowledge and insight” dispelled ignorance (avijjā). Here ignorance stands as a mighty impediment all through saṃsāra, obstructing spiritual progress on the one hand, and on the other hand generating fuel for fresh rebirth and storing it in the accumulator of volitional activities (saṅkhāras). Of course, all these four cankers taken as mental states (cetasikas) come under lobha, dosa and moha. Of these cankers (āsavas), the canker of sensuality is eradicated at the stage of Anāgāmi; the canker of false views is eradicated at the stage of Sotāpanna, while the cankers of existence and ignorance are eradicated at the stage of arahathood.

Nibbāna can be attained only through the total eradication of these four cankers by extra-sensory Wisdom which stands as the apex of the Buddha’s Noble Eightfold Path in its triple division of Morality (sīla), Concentration (samādhi) and Wisdom (paññā). Let us step into the “Chariot” and take the “Straight Road” that will bring us to “Nibbāna’s presence.” I shall conclude this Essay with an appropriate quotation from the Devatā Saṃyutta of the Saṃyutta Nikāya (SN 1:5, 6):

’Straight’ is the name that Road is called, and ’Free
From Fear’ the Quarter whither thou art bound.
Thy Chariot [15] is the ’Silent Runner’ named, [16]
With Wheels of Righteous Effort [17] fitted well.
Conscience the Leaning Board; [18] the Drapery [19]
Is Heedfulness; the Driver is the Law,
I say, and Right Views, they that run before. [20]
And be it woman, be it man for whom,
Such chariot doth wait, by that same car.
Into Nibbāna’s presence shall they come.


  1. It means the cankers (āsavā). This figure of speech means an Arahant who is thoroughly cleansed of the poisonous mix or ooze. Āsavā also mean an intoxicant drug. [Back]
  2. The Buddha. [Back]
  3. Note by Nārada Thera: Nibbāna is Deliverance from suffering (vimokkha). It is called Void because it is void of lust, hatred and ignorance, not because it is nothingness or annihilation. Nibbāna is a positive supramundane state which cannot be expressed in mundane word. It is Signless because it is free from the signs of lust etc. Arahants experience Nibbānic bliss while alive. It is not correct to say that Arahants exist after death, for Nibbāna is neither eternalism nor nihilism. In Nibbāna nothing is eternalised, nor is anything, except passions, annihilated. Arahants experience Nibbānic bliss by attaining to the fruit of Arahantship in this life itself. [Back]
  4. Tr. by the Venerable Nārada Mahā Thera. [Back]
  5. Those who are neither sekhas nor asekhas, i.e. those who have neither entered the Path nor attained to the fruition of Arhantship (arahat-phalaṭṭha). [Back]
  6. Rāga, dosa, moha, the extinction of which is Nibbāna. [Back]
  7. The āsavas: sensuality, lust for continued life, false views and ignorance. [Back]
  8. Craving (taṇhā), it is compared to the interwoven foliage of ferns and bamboos. Craving entwines one from within and without. [Back]
  9. form (rūpa). [Back]
  10. feelings (vedanā). [Back]
  11. perceptions (saññā). [Back]
  12. consciousness (viññāṇa). [Back]
  13. mental formations (saṅkhārā) These are the five aggregates (khandhas) or “congeries” that make up the psychophysical combination called a “being.” [Back]
  14. He has attained Nibbāna. [Back]
  15. The Noble Eightfold Path. [Back]
  16. Literally the Uncreaking, unlike a chariot where the axle fits badly into naves, or which squeaks when mounted. Comy. [Back]
  17. The Dhamma-cakka, says the Ven. Buddhaghosa. [Back]
  18. Lest the warriors fall out. Comy. Conscience is consciousness. [Back]
  19. Such as. a lion's skin etc. Comy. [Back]
  20. To prepare the way [Back]