This process of birth and death continues ad infinitum until this flux is transmuted, so to say, to Nibbanadhatu, the ultimate goal of Buddhists. 

The Pali word Nibbana is formed of Ni and Vana. Ni is a negative particle and Vana means lusting or craving. "It is called Nibbana, in that it is a departure from the craving which is called Vana, lusting." Literally, Nibbana means non-attachment. 

It may also be defined as the extinction of lust, hatred and ignorance, "The whole world is in flames," says the Buddha. "By what fire is it kindled? By the fire of lust, hatred and ignorance, by the fire of birth, old age, death, pain, lamentation, sorrow, grief and despair it is kindled." 

It should not be understood that Nibbana is a state of nothingness or annihilation owing to the fact that we cannot perceive it with our worldly knowledge. One cannot say that there exists no light just because the blind man does not see it. In that well known story, too, the fish arguing with his friend, the turtle, triumphantly concluded that there exists no land. 

Nibbana of the Buddhists is neither a mere nothingness nor a state of annihilation, but what it is no words can adequately express. Nibbana is a Dhamma which is "unborn, unoriginated, uncreated and unformed." Hence, it is eternal (Dhuva), desirable (Subha), and happy (Sukha). 

In Nibbana nothing is "eternalized," nor is anything "annihilated," besides suffering. 

According to the Books references are made to Nibbana as Sopadisesa and Anupadisesa. These, in fact, are not two kinds of Nibbana, but the one single Nibbana, receiving its name according to the way it is experienced before and after death. 

Nibbana is not situated in any place nor is it a sort of heaven where a transcendental ego resides. It is a state which is dependent upon this body itself. It is an attainment (Dhamma) which is within the reach of all. Nibbana is a supramundane state attainable even in this present life. Buddhism does not state that this ultimate goal could be reached only in a life beyond. Here lies the chief difference between the Buddhist conception of Nibbana and the non-Buddhist conception of an eternal heaven attainable only after death or a union with a God or Divine Essence in an after-life. When Nibbana is realized in this life with the body remaining, it is called Sopadisesa Nibbana-dhatu. When an Arahat attains Parinibbana, after the dissolution of his body, without any remainder of physical existence it is called Anupadisesa Nibbana-dhatu.

In the words of Sir Edwin Arnold: 

"If any teach Nirvana is to cease Say unto such they lie. If any teach Nirvana is to love Say unto such they err." 

From a metaphysical standpoint Nibbana is deliverance from suffering. From a psychological standpoint Nibbana is the eradication of egoism. From an ethical standpoint Nibbana is the destruction of lust, hatred and ignorance. 

Does the Arahat exist or not after death? 

The Buddha replies: 

"The Arahat who has been released from 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 neither reborn nor not reborn would not fit the case." 

One cannot say that an Arahat is reborn as all passions that condition rebirth are eradicated; nor can one say that the Arahat 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 whether the electron's position changes with time, we must say 'no'; if we ask whether the electron is at rest, 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 conditions of man's self after death; [*] but they are not familiar answers from the tradition of the 17th and 18th century science." 

* [Evidently the writer is referring to the state of an Arahat after death.]

.The Buddha I I The Dhamma: Is it a Philosophy?I I Is it a Religion? I I Is Buddhism an Ethical System? I  I Some Salient Features of Buddhism I I Kamma or the Law of Moral Causation I I Re-Birth I I Paticca Samuppada (Dependent Origination) I I  Anatta or Soul-lessness I I Nibanna I I The Path to Nibbana