Though right concentration claims the last place among the factors of the Noble Eightfold Path, concentration itself does not mark the path’s culmination. The attainment of concentration makes the mind still and steady, unifies its concomitants, opens vast vistas of bliss, serenity, and power. But by itself it does not suffice to reach the highest accomplishment, release from the bonds of suffering. To reach the end of suffering demands that the Eightfold Path be turned into an instrument of discovery, that it be used to generate the insights unveiling the ultimate truth of things. This requires the combined contributions of all eight factors, and thus a new mobilization of right view and right intention. Up to the present point these first two path factors have performed only a preliminary function. Now they have to be taken up again and raised to a higher level. Right view is to become a direct seeing into the real nature of phenomena, previously grasped only conceptually; right intention, to become a true renunciation of defilements born out of deep understanding.

Before we turn to the development of wisdom, it will be helpful to inquire why concentration is not adequate to the attainment of liberation. Concentration does not suffice to bring liberation because it fails to touch the defilements at their fundamental level. The Buddha teaches that the defilements are stratified into three layers: the stage of latent tendency, the stage of manifestation, and the stage of transgression. The most deeply grounded is the level of latent tendency (anusaya), where a defilement merely lies dormant without displaying any activity. The second level is the stage of manifestation (pariyutthana), where a defilement, through the impact of some stimulus, surges up in the form of unwholesome thoughts, emotions, and volitions. Then, at the third level, the defilement passes beyond a purely mental manifestation to motivate some unwholesome action of body or speech. Hence this level is called the stage of transgression (vitikkama).

The three divisions of the Noble Eightfold Path provide the check against this threefold layering of the defilements. The first, the training in moral discipline, restrains unwholesome bodily and verbal activity and thus prevents defilements from reaching the stage of transgression. The training in concentration provides the safeguard against the stage of manifestation. It removes already manifest defilements and protects the mind from their continued influx. But even though concentration may be pursued to the depths of full absorption, it cannot touch the basic source of affliction — the latent tendencies lying dormant in the mental continuum. Against these concentration is powerless, since to root them out calls for more than mental calm. What it calls for, beyond the composure and serenity of the unified mind, is wisdom (pañña), a penetrating vision of phenomena in their fundamental mode of being.

Wisdom alone can cut off the latent tendencies at their root because the most fundamental member of the set, the one which nurtures the others and holds them in place, is ignorance (avijja), and wisdom is the remedy for ignorance. Though verbally a negative, “unknowing,” ignorance is not a factual negative, a mere privation of right knowledge. It is, rather, an insidious and volatile mental factor incessantly at work inserting itself into every compartment of our inner life. It distorts cognition, dominates volition, and determines the entire tone of our existence. As the Buddha says: “The element of ignorance is indeed a powerful element” (SN 14:13).

At the cognitive level, which is its most basic sphere of operation, ignorance infiltrates our perceptions, thoughts, and views, so that we come to misconstrue our experience, overlaying it with multiple strata of delusions. The most important of these delusions are three: the delusions of seeing permanence in the impermanent, of seing satisfaction in the unsatisfactory, and of seeing a self in the selfless.66 Thus we take ourselves and our world to be solid, stable, enduring entities, despite the ubiquitous reminders that everything is subject to change and destruction. We assume we have an innate right to pleasure, and direct our efforts to increasing and intensifying our enjoyment with an anticipatory fervor undaunted by repeated encounters with pain, disappointment, and frustration. And we perceive ourselves as self-contained egos, clinging to the various ideas and images we form of ourselves as the irrefragable truth of our identity.

Whereas ignorance obscures the true nature of things, wisdom removes the veils of distortion, enabling us to see phenomena in their fundamental mode of being with the vivacity of direct perception. The training in wisdom centers on the development of insight (vipassana-bhavana), a deep and comprehensive seeing into the nature of existence which fathoms the truth of our being in the only sphere where it is directly accessible to us, namely, in our own experience. Normally we are immersed in our experience, identified with it so completely that we do not comprehend it. We live it but fail to understand its nature. Due to this blindness experience comes to be misconstrued, worked upon by the delusions of permanence, pleasure, and self. Of these cognitive distortions, the most deeply grounded and resistant is the delusion of self, the idea that at the core of our being there exists a truly established “I” with which we are essentially identified. This notion of self, the Buddha teaches, is an error, a mere presupposition lacking a real referent. Yet, though a mere presupposition, the idea of self is not inconsequential. To the contrary, it entails consequences that can be calamitous. Because we make the view of self the lookout point from which we survey the world, our minds divide everything up into the dualities of “I” and “not I,” what is “mine” and what is “not mine.” Then, trapped in these dichotomies, we fall victim to the defilements they breed, the urges to grasp and destroy, and finally to the suffering that inevitably follows.

To free ourselves from all defilements and suffering, the illusion of selfhood that sustains them has to be dispelled, exploded by the realization of selflessness. Precisely this is the task set for the development of wisdom. The first step along the path of development is an analytical one. In order to uproot the view of self, the field of experience has to be laid out in certain sets of factors, which are then methodically investigated to ascertain that none of them singly or in combination can be taken as a self. This analytical treatment of experience, so characteristic of the higher reaches of Buddhist philosophical psychology, is not intended to suggest that experience, like a watch or car, can be reduced to an accidental conglomeration of separable parts. Experience does have an irreducible unity, but this unity is functional rather than substantial; it does not require the postulate of a unifying self separate from the factors, retaining its identity as a constant amidst the ceaseless flux.

The method of analysis applied most often is that of the five aggregates of clinging (panc’upadanakkhandha): material form, feeling, perception, mental formations, and consciousness.67 Material form constitutes the material side of existence: the bodily organism with its sense faculties and the outer objects of cognition. The other four aggregates constitute the mental side. Feeling provides the affective tone, perception the factor of noting and identifying, the mental formations the volitional and emotive elements, and consciousness the basic awareness essential to the whole occasion of experience. The analysis by way of the five aggregates paves the way for an attempt to see experience solely in terms of its constituting factors, without slipping in implicit references to an unfindable self. To gain this perspective requires the development of intensive mindfulness, now applied to the fourth foundation, the contemplation of the factors of existence (dhammanupassana). The disciple will dwell contemplating the five aggregates, their arising and passing:

Or the disciple may instead base his contemplation on the six internal and external spheres of sense experience, that is, the six sense faculties and their corresponding objects, also taking note of the “fetters” or defilements that arise from such sensory contacts:

The view of self is further attenuated by examining the factors of existence, not analytically, but in terms of their relational structure. Inspection reveals that the aggregates exist solely in dependence on conditions. Nothing in the set enjoys the absolute self-sufficiency of being attributed to the assumed “I.” Whatever factors in the body-mind complex be looked at, they are found to be dependently arisen, tied to the vast net of events extending beyond themselves temporally and spatially. The body, for example, has arisen through the union of sperm and egg and subsists in dependence on food, water, and air. Feeling, perception, and mental formations occur in dependence on the body with its sense faculties. They require an object, the corresponding consciousness, and the contact of the object with the consciousness through the media of the sense faculties. Consciousness in its turn depends on the sentient organism and the entire assemblage of co-arisen mental factors. This whole process of becoming, moreover, has arisen from the previous lives in this particular chain of existences and inherit all the accumulated kamma of the earlier existences. Thus nothing possesses a self-sufficient mode of being. All conditioned phenomena exist relationally, contingent and dependent on other things.

The above two steps — the factorial analysis and the discernment of relations — help cut away the intellectual adherence to the idea of self, but they lack sufficient power to destroy the ingrained clinging to the ego sustained by erroneous perception. To uproot this subtle form of ego-clinging requires a counteractive perception: direct insight into the empty, coreless nature of phenomena. Such an insight is generated by contemplating the factors of existence in terms of their three universal marks — impermanence (aniccata), unsatisfactoriness (dukkhata), and selflessness (anattata). Generally, the first of the three marks to be discerned is impermanence, which at the level of insight does not mean merely that everything eventually comes to an end. At this level it means something deeper and more pervasive, namely, that conditioned phenomena are in constant process, happenings which break up and perish almost as soon as they arise. The stable objects appearing to the senses reveal themselves to be strings of momentary formations (sankhara); the person posited by common sense dissolves into a current made up of two intertwining streams — a stream of material events, the aggregate of material form, and a stream of mental events, the other four aggregates.

When impermanence is seen, insight into the other two marks closely follows. Since the aggregates are constantly breaking up, we cannot pin our hopes on them for any lasting satisfaction. Whatever expectations we lay on them are bound to be dashed to pieces by their inevitable change. Thus when seen with insight they are dukkha, suffering, in the deepest sense. Then, as the aggregates are impermanent and unsatisfactory, they cannot be taken as self. If they were self, or the belongings of a self, we would be able to control them and bend them to our will, to make them everlasting sources of bliss. But far from being able to exercise such mastery, we find them to be grounds of pain and disappointment. Since they cannot be subjected to control, these very factors of our being are anatta: not a self, not the belongings of a self, just empty, ownerless phenomena occurring in dependence on conditions.

When the course of insight practice is entered, the eight path factors become charged with an intensity previously unknown. They gain in force and fuse together into the unity of a single cohesive path heading towards the goal. In the practice of insight all eight factors and three trainings co-exist; each is there supporting all the others; each makes its own unique contribution to the work. The factors of moral discipline hold the tendencies to transgression in check with such care that even the thought of unethical conduct does not arise. The factors of the concentration group keep the mind firmly fixed upon the stream of phenomena, contemplating whatever arises with impeccable precision, free from forgetfulness and distraction. Right view, as the wisdom of insight, grows continually sharper and deeper; right intention shows itself in a detachment and steadiness of purpose bringing an unruffled poise to the entire process of contemplation.

Insight meditation takes as its objective sphere the “conditioned formations” (sankhara) comprised in the five aggregates. Its task is to uncover their essential characteristics: the three marks of impermanence, unsatisfactoriness, and selflessness. Because it still deals with the world of conditioned events, the Eightfold Path in the stage of insight is called the mundane path (lokiyamagga). This designation in no way implies that the path of insight is concerned with mundane goals, with achievements falling in the range of samsara. It aspires to transcendence, it leads to liberation, but its objective domain of contemplation still lies within the conditioned world. However, this mundane contemplation of the conditioned serves as the vehicle for reaching the unconditioned, for attaining the supramundane. When insight meditation reaches its climax, when it fully comprehends the impermanence, unsatisfactoriness, and selflessness of everything formed, the mind breaks through the conditioned and realizes the unconditioned, Nibbana. It sees Nibbana with direct vision, makes it an object of immediate realization.

The breakthrough to the unconditioned is achieved by a type of consciousness or mental event called the supramundane path (lokuttaramagga). The supramundane path occurs in four stages, four “supramundane paths,” each marking a deeper level of realization and issuing in a fuller degree of liberation, the fourth and last in complete liberation. The four paths can be achieved in close proximity to one another — for those with extraordinarily sharp faculties even in the same sitting — or (as is more typically the case) they can be spread out over time, even over several lifetimes.70 The supramundane paths share in common the penetration of the Four Noble Truths. They understand them, not conceptually, but intuitively. They grasp them through vision, seeing them with self-validating certainty to be the invariable truths of existence. The vision of the truths which they present is complete at one moment. The four truths are not understood sequentially, as in the stage of reflection when thought is the instrument of understanding. They are seen simultaneously: to see one truth with the path is to see them all.

As the path penetrates the four truths, the mind exercises four simultaneous functions, one regarding each truth. It fully comprehends the truth of suffering, seeing all conditioned existence as stamped with the mark of unsatisfactoriness. At the same time it abandons craving, cuts through the mass of egotism and desire that repeatedly gives birth to suffering. Again, the mind realizes cessation, the deathless element Nibbana, now directly present to the inner eye. And fourthly, the mind develops the Noble Eightfold Path, whose eight factors spring up endowed with tremendous power, attained to supramundane stature: right view as the direct seeing of Nibbana, right intention as the mind’s application to Nibbana, the triad of ethical factors as the checks on moral transgression, right effort as the energy in the path-consciousness, right mindfulness as the factor of awareness, and right concentration as the mind’s one-pointed focus. This ability of the mind to perform four functions at the same moment is compared to a candle’s ability to simultaneously burn the wick, consume the wax, dispel darkness, and give light.71

The supramundane paths have the special task of eradicating the defilements. Prior to the attainment of the paths, in the stages of concentration and even insight meditation, the defilements were not cut off but were only debilitated, checked and suppressed by the training of the higher mental faculties. Beneath the surface they continued to linger in the form of latent tendencies. But when the supramundane paths are reached, the work of eradication begins.

Insofar as they bind us to the round of becoming, the defilements are classified into a set of ten “fetters” (samyojana) as follows: (1) personality view, (2) doubt, (3) clinging to rules and rituals, (4) sensual desire, (5) aversion, (6) desire for fine-material existence, (7) desire for immaterial existence, (8) conceit, (9) restlessness, and (10) ignorance. The four supramundane paths each eliminate a certain layer of defilements. The first, the path of stream-entry (sotapatti-magga), cuts off the first three fetters, the coarsest of the set, eliminates them so they can never arise again. “Personality view” (sakkaya-ditthi), the view of a truly existent self in the five aggregates, is cut off since one sees the selfless nature of all phenomena. Doubt is eliminated because one has grasped the truth proclaimed by the Buddha, seen it for oneself, and so can never again hang back due to uncertainty. And clinging to rules and rites is removed since one knows that deliverance can be won only through the practice of the Eightfold Path, not through rigid moralism or ceremonial observances.

The path is followed immediately by another state of supramundane consciousness known as the fruit (phala), which results from the path’s work of cutting off defilements. Each path is followed by its own fruit, wherein for a few moments the mind enjoys the blissful peace of Nibbana before descending again to the level of mundane consciousness. The first fruit is the fruit of stream-entry, and a person who has gone through the experience of this fruit becomes a “stream-enterer” (sotapanna). He has entered the stream of the Dhamma carrying him to final deliverance. He is bound for liberation and can no longer fall back into the ways of an unenlightened worldling. He still has certain defilements remaining in his mental makeup, and it may take him as long as seven more lives to arrive at the final goal, but he has acquired the essential realization needed to reach it, and there is no way he can fall away.

An enthusiastic practitioner with sharp faculties, after reaching stream-entry, does not relax his striving but puts forth energy to complete the entire path as swiftly as possible. He resumes his practice of insight contemplation, passes through the ascending stages of insight-knowledge, and in time reaches the second path, the path of the once-returner (sakadagami-magga). This supramundane path does not totally eradicate any of the fetters, but it attenuates the roots of greed, aversion, and delusion. Following the path the meditator experiences its fruit, then emerges as a “once-returner” who will return to this world at most only one more time before attaining full liberation.

But our practitioner again takes up the task of contemplation. At the next stage of supramundane realization he attains the third path, the path of the non-returner (anagami-magga), with which he cuts off the two fetters of sensual desire and ill will. From that point on he can never again fall into the grip of any desire for sense pleasure, and can never be aroused to anger, aversion, or discontent. As a non-returner he will not return to the human state of existence in any future life. If he does not reach the last path in this very life, then after death he will be reborn in a higher sphere in the fine-material world (rupaloka) and there reach deliverance.

But our meditator again puts forth effort, develops insight, and at its climax enters the fourth path, the path of arahatship (arahatta-magga). With this path he cuts off the five remaining fetters — desire for fine-material existence and desire for immaterial existence, conceit, restlessness, and ignorance. The first is the desire for rebirth into the celestial planes made accessible by the four jhanas, the planes commonly subsumed under the name “the Brahma-world.” The second is the desire for rebirth into the four immaterial planes made accessible by the achievement of the four immaterial attainments. Conceit (mana) is not the coarse type of pride to which we become disposed through an over-estimation of our virtues and talents, but the subtle residue of the notion of an ego which subsists even after conceptually explicit views of self have been eradicated. The texts refer to this type of conceit as the conceit “I am” (asmimana). Restlessness (uddhacca) is the subtle excitement which persists in any mind not yet completely enlightened, and ignorance (avijja) is the fundamental cognitive obscuration which prevents full understanding of the Four Noble Truths. Although the grosser grades of ignorance have been scoured from the mind by the wisdom faculty in the first three paths, a thin veil of ignorance overlays the truths even in the non-returner.

The path of arahatship strips away this last veil of ignorance and, with it, all the residual mental defilements. This path issues in perfect comprehension of the Four Noble Truths. It fully fathoms the truth of suffering; eradicates the craving from which suffering springs; realizes with complete clarity the unconditioned element, Nibbana, as the cessation of suffering; and consummates the development of the eight factors of the Noble Eightfold Path.

With the attainment of the fourth path and fruit the disciple emerges as an arahant, one who in this very life has been liberated from all bonds. The arahant has walked the Noble Eightfold Path to its end and lives in the assurance stated so often in the formula from the Pali canon: “Destroyed is birth; the holy life has been lived; what had to be done has been done; there is no coming back to any state of being.” The arahant is no longer a practitioner of the path but its living embodiment. Having developed the eight factors of the path to their consummation, the Liberated One lives in the enjoyment of their fruits, enlightenment and final deliverance.

This completes our survey of the Noble Eightfold Path, the way to deliverance from suffering taught by the Buddha. The higher reaches of the path may seem remote from us in our present position, the demands of practice may appear difficult to fulfill. But even if the heights of realization are now distant, all that we need to reach them lies just beneath our feet. The eight factors of the path are always accessible to us; they are mental components which can be established in the mind simply through determination and effort. We have to begin by straightening out our views and clarifying our intentions. Then we have to purify our conduct — our speech, action, and livelihood. Taking these measures as our foundation, we have to apply ourselves with energy and mindfulness to the cultivation of concentration and insight. The rest is a matter of gradual practice and gradual progress, without expecting quick results. For some progress may be rapid, for others it may be slow, but the rate at which progress occurs should not cause elation or discouragement. Liberation is the inevitable fruit of the path and is bound to blossom forth when there is steady and persistent practice. The only requirements for reaching the final goal are two: to start and to continue. If these requirements are met there is no doubt the goal will be attained. This is the Dhamma, the undeviating law.