THE WAY TO NIBBĀNA (III)
Transcient are all conditioned things,
Sorrowful are all conditioned things,
Soulless are all conditioned and non-conditioned.
When the Jhānas are developed by temporarily inhibiting the Hindrances (Nīvarana) the mind is so purified that it resembles a polished mirror, where everything is clearly reflected in true perspective. Still there is not complete freedom from unwholesome thoughts, for by concentration the evil tendencies are only temporarily inhibited. They may rise to the surface at quite unexpected moments.
Discipline regulates words and deeds; concentration controls the mind; but it is Insight (pa257;), the third and the final stage, that enables the aspirant to Sainthood to eradicate wholly the defilements inhibited by Samādhi.
At the outset he cultivates 'Purity of Vision' (ditthi visuddhi)  in order to see things as they truly are. With one-pointed mind he analyses and examines this so-called being. This searching examination shows what he has called personality, to be merely a complex compound of mind and matter which are in a state of constant flux.
Having thus gained a correct view of the real nature of this so-called being, freed from the false notion of a permanent soul, he searches for the causes of this "I" personality. He realizes that there is nothing in the world but is conditioned by some cause or causes, past or present, and that his present existence is due to past ignorance (avijjā), craving (tanhā) grasping (upādāna), Kamma, and physical food of the present life. On account of these five causes this so-called being has arisen, and as past causes have conditioned the present, so the present will condition the future. Meditating thus, he transcends all doubts with regard to past, present and future. 
Thereupon he contemplates the truth that all conditioned things are transient (anicca), subject to suffering (dukkha), and devoid of an immortal soul (anattā). Wherever he turns his eyes he sees naught but these three characteristics standing out in bold relief. He realizes that life is a mere flux conditioned by internal and external causes. Nowhere does he find any genuine happiness, for everything is fleeting.
As he thus contemplates the real nature of life and is absorbed in meditation, a day comes when, to his surprise. he witnesses an aura (obhāsa) emitted by his body. He experiences an unprecedented pleasure, happiness, and quietude. He becomes even-minded, religious fervour increases, mindfulness becomes clear and insight keen. Mistaking this advanced state of moral progress for Sainthood, chiefly owing to the presence of the aura, he develops a liking for this mental state. Soon the realization comes that these new developments are impediments to moral progress, and he cultivates the purity of knowledge with regard to the Path and Not-Path. 
Perceiving the right path, he resumes his meditation on the arising (udaya 57;na) and passing away (vaya 57;na) of all conditioned things. Of these two states the latter becomes more impressed on his mind since change is more conspicuous than becoming. Therefore he directs his attention to contemplation of the dissolution of things (bhanga 57;na). He perceives that both mind and matter which constitute this so-called being are in a state of constant flux, not remaining for two consecutive moments the same. To him then comes the knowledge that all dissolving things are fearful (bhaya 57;na). The whole world appears to him as a pit of burning embers -- a source of danger. Subsequently he reflects on the wretchedness and vanity (ādīnava 57;na) of the fearful and deluded world, and gets a feeling of disgust (nibbidā 57;na) followed by a strong will for deliverance from it (muukamyatā 57;na).
With this object in view, he resumes his meditations on the three characteristics of transiency, sorrow, and soullessness (patisankhā 57;na) and thereafter develops complete equanimity towards all conditioned things -- having neither attachment nor aversion for any worldly object (upekkhā 57;na) 
Reaching this point of spiritual culture, he chooses one of the three characteristics for his object of special endeavour and intently cultivates insight in that particular direction until the glorious day when he first realizes Nibbāna,  his ultimate goal.
"As the traveller by night sees the landscape around him by a flash of lightning and the picture so obtained swims long thereafter before his dazzled eyes, so the individual seeker, by the flashing light of insight, glimpses Nibbāna with such clearness that the after-picture never more fades from his mind. "
When the spiritual pilgrim realizes Nibbāna for the first time, he is called a Sotāpanna, one who has entered the stream that leads to Nibbāna for the first time.
The stream represents the noble Eightfold Path.
A Stream-Winner is no more a worlding (puthujjana), but an Ariya (Noble).
On attaining this first stage of Sainthood, he eradicates the following three Fetters (samyojana) that bind him to existence -- namely,
1/- Sakkāya-ditthi (sati + kāye + ditthi) -- literally, view, when a group or compound exists. Here kāya refers to the five Aggregates of matter -- feeling, perception, mental states, and consciousness. The view that there exists an unchanging entity, a permanent soul, when there is a complex-compound of psycho-physical aggregates, is termed sakkāyaditthi. Dhammasangani enumerates twenty kinds of such soul-theories.  Sakkāya-ditthi is usually rendered as self-illusion, theory of individuality, or illusion of individualism.
2/- Vicikicchā -- Doubts. They are doubts about (i) the Buddha, (ii) the Dhamma, (iii) the Sangha, (iv) the disciplinary rules (sikkha), (v) the past, (vi) the future, (vii) both the past and the future, and (viii) Dependent Origination (Paticca-Samuppāda).
3/- Sīlabbātaparāmāsa -- Adherence to (wrongful) rites and ceremonies.
Dhammasangani explains it thus: "it is the theory held by ascetics and brahmins outside this doctrine that purification is obtained by rules of moral conduct, or by rites, or by both rites of moral conduct and rites. "
For the eradication of the remaining seven Fetters a Sotāpanna is reborn seven times at the most. He gains implicit confidence in the Buddha, the Dhamrna, and the Sangha. He would not for any reason violate any of the five precepts. He is not subject to rebirth in states of woe as he is destined to Enlightenment.
With fresh courage as a result of this distant glimpse of Nibbāna, the noble pilgrim makes a rapid progress, and perfecting his insight becomes a Sakadāgāmi (Once-Returner), the second stage of Sainthood, by attenuating two other Fetters -- namely, sense-desires (kāmarāga) and illwill (pātigha).
Now he is called a Once-Returner because he is born in the human realm only once, should he not attain Arahantship in that birth itself. It is interesting to note that the Ariya Saint who has attained the second stage of Sainthood can only weaken these two powerful Fetters with which he is bound from a beginningless past. At times, though to a slight extent, he may harbour thoughts of lust and anger.
It is by attaining the third stage of Sainthood, that of the Anāgāmi (Never-Returner), that he completely eradicates those two Fetters. Thereafter he neither returns to this world nor is he born in the celestial realms, since he has rooted out the desire for sensual gratification. After death he is reborn in the Pure Abodes (Suddhāvāsa), an environment reserved for Anāgāmis. There he attains Arahantship and lives till the end of his life.
When a layman becomes an Anāgāmi, he leads a celibate life.
The Anāgāmi Saint now makes his final advance and destroying the remaining five Fetters -- namely, attachment to Realms of Form (rūparāga), attachment to Formless Realms (arūparāga), pride (māna), restlessness (uddhacca), and ignorance (avijjā) -- attains Arahantship, the final stage of Sainthood.
Stream-Winners, Once-Returners, Never-Returners are called Sekhas because they have yet to undergo a training. Arahants are called Asekhas (Adepts) because they no more undergo any training.
An Arahant, literally, a Worthy One, is not subject to rebirth because he does not accumulate fresh Kammic activities. The seeds of his reproduction have all been destroyed.
The Arahant realizes that what was to be accomplished has been done, a heavy burden of sorrow has finally been relinquished, and all forms of craving and all shades of ignorance are totally annihilated. The happy pilgrim now stands on heights more than celestial, far removed from uncontrolled passions and the defilements of the world, experiencing the unutterable bliss of Nibbāna.
Rebirth can no longer affect him since no more reproductive seeds are formed by fresh kammic activities.
Though an Arahant he is not wholly free from physical suffering, as this experience of the bliss of Deliverance is only intermittent nor has he yet cast off his material body.
An Arahant is called an asekha, one who does not undergo training, as he has lived the Holy Life and has accomplished his object. The other Saints from the Sotāpatti stage to the Arahant Path Stage are called Sekhas because they still undergo training.
It may be mentioned in this connection that Anāgāmis and Arahants who have developed the Rūpa and Arūpa Jhānas could experience the Nibbānic bliss uninterruptedly for as long as seven days even in this life. This, in Pāli, is known as Nirodha-Samāpatti.  An Ariya, in this state, is wholly free from pain, and his mental activities are all suspended. His stream of consciousness temporarily ceases to flow.
With regard to the difference between one who has attained Nirodha-Samāpatti and a dead man, the Visuddhi Magga states: "In the corpse, not only are the plastic forces of the body (i.e., respiration), speech and mind stilled and quiescent, but also vitality is exhausted, heat is quenched, and the faculties of sense broken up, whereas in the Bhikkhu in ecstasy vitality persists, heart abides, and the faculties are clear, although respiration, observation, and perception are stilled and quiescent. 
According to Buddhism, in conventional terms, this is the highest form of bliss possible in this life.
Why does an Arahant continue to live when he has already attained Nibbāna?
It is because the Kammic force which produced his birth is still not spent. To quote Schopenhauer, it is like the potter's wheel from which the hand of the potter has been lifted, or, to cite a better illustration from our own books -- an Arahant is like a branch that is severed from the tree. It puts forth no more fresh leaves, flowers and fruits, as it is no longer supported by the sap of the tree.
Those which already existed however last till the death of that particular branch.
The Arahant lives out his life-span adding no more fresh Kamma to his store, and utterly indifferent to death.
Like Venerable Sāriputta he would say:
"Not fain am I to die nor yet to live.
I shall lay down this mortal frame anon
With mind alert, with consciousness controlled.
With thought of death I dally not, nor yet
Delight in living. I await the hour
Like any hireling who hath done his task.2"
What happens to the Arahant after his passing away?
As a flame blown to and fro by the wind goes out and cannot be registered, so says the Buddha, an Arahant, set free from mind and matter, has disappeared and cannot be registered.
Has such an Arahant then merely disappeared, or does he indeed no longer exist?
For him who has disappeared, states the Sutta Nipāta, there exists no form by which they could say, 'he is'. When all conditions are cut off, all matter for discussion is also cut off.
The Udāna explains this intricate point thus:
"As the fiery sparks from a forge are one by one extinguished,
And no one knows where they have gone
So it is with those who have attained to complete emancipation,
Who have crossed the flood of desire,
Who have entered the calm delight, of those no trace remains. "
The Majjhima Nikāya also relates an interesting discussion between the Buddha and Vacchagotta concerning this very question. 
Vacchagotta, a wandering ascetic, approached the Buddha and questioned:
"But, Gotama, where is the Bhikkhu who is delivered of mind reborn?
He was of course referring to the Arahant.
The Buddha replied:--
"Vaccha, to say that he is reborn would not fit the case.
"Then, Gotama, he is not reborn.
"Vaccha, to say that he is not reborn would not fit the case.
"Then, Gotama, he is both reborn and not reborn.
"Vaccha, to say that he is both reborn and not reborn would not fit the case.
"Then, Gotama, he is neither reborn nor not reborn.
"Vaccha, to say that he is neither reborn nor not reborn would not fit the case.
Vaccha was baffled on hearing these seemingly inconsistent answers, and, in his confusion, exclaimed:
"Gotama, I am at a loss to think in this matter, and I have become greatly confused.
"Enough, O Vaccha. Be not at a loss to think in this matter, and be not greatly confused. Profound, O Vaccha, is this doctrine, recondite and difficult of comprehension, good, excellent, and not to be reached by mere reasoning, subtle and intelligible only to the wise and it is a hard doctrine for you to learn, who belong to another sect, to another faith, to another persuasion, to another discipline, and who sit at the feet of another teacher. Therefore, O Vaccha, I shall now question you, and do you make answer as may seem to you good. What think you, Vaccha? Suppose a fire were to burn in front of you, would you be aware that fire was burning in front of you?
"Gotama, if a fire were to burn in front of me, I should be aware that a fire was burning in front of me.
"But suppose, Vaccha, someone were to ask you: On what does this fire that is burning in front of you depend?' What would you answer, Vaccha ?
"I would answer, O Gotama, 'it is on fuel of grass and wood that this fire burning in front of me depends.'
"But Vaccha, if the fire in front of you were to become extinct, would you be aware that the fire in front of you had become extinct ?
"Gotama, if the fire in front of me were to become extinct, I should be aware that the fire in front of me had become extinct.
"But, Vacca, if someone were to ask you -- 'In what direction has that fire gone, East or West, North or South?' What would you say, Vaccha?
"The question would not fit the case, Gotama, for the fire depended on fuel of grass and wood, and when that fuel has all gone, and it can get no other, being thus without nutriment, it is said to be extinct.
"In exactly the same way, Vaccha, all forms, sensations, perceptions, mental activities, and consciousness have been abandoned, uprooted, made like a palmyra stump, become extinct, and not liable to spring up in the future.
"The Saint, O Vaccha, who has been released from what are styled the Five Aggregates, is deep, immeasurable like the mighty ocean. To say that he is reborn would not fit the case. To say that he is not reborn would not fit the case. To say that he is neither reborn nor not reborn would not fit the case."
One cannot say that the Arahant is reborn as all passions that condition rebirth are eradicated, nor can one say that the Arahant is annihilated, for there is nothing to annihilate.
Robert Oppenheimer, a scientist, writes:-
"If we ask, for instance, whether the position of the electron remains the same, we must say 'no', if we ask wether the electron's position changes with time, we must say 'no'; if we ask whether it is in motion, we must say 'no.'
"The Buddha has given such answers when interrogated as to the condition of man's self after death.  But they are not familiar answers from the tradition of the 17th and 18th century science."
Nibbāna, it may safely be concluded, is obtained by the complete cessation of the defilements (kilesa), but the real nature of this
From a metaphysical standpoint, Nibbāna is complete deliverance from suffering. From a psychological standpoint, Nibbāna is the eradication of egoism. From an ethical standpoint, Nibbāna is the destruction of lust, hatred and ignorance.