Nirvana is a key concept in Buddhism but it causes a fundamental and deep problem in Buddhism with which it has struggled throughout its history. To understand how Buddhism got into this situation with a fundamental contradiction at its heart can only be understood if we take into account the evolution of the Buddhist heresy out of the Indo-European worldview in the form of Hinduism.
The problem is that Buddhism is derived from the Indo-European worldview which is unique in having Being as a fundamental linguistic concept. Buddhism is a attempt to get away from Being and back to Existence. But the unfortunate problem is that once you have Being, if you try to return to existence, it does not mean you can return to the pristine state prior to the advent of Being. This is fundamental problem that once you are sullied with the illusory nature of Being you cannot return directly to a pristine state directly. This is part of the insidious nature of Maya.
In some way, it is this contradiction that has made Buddhism so deep. if it did not have this contradiction that comes from its source in Hinduism then it would not nearly be as interesting philosophically. Because Buddhism has struggled with this fundamental contradiction at its core that it takes from Hinduism its depth is much greater.
The basic problem is that Buddhism says that things are empty, especially the self, that they do not have Being (Sat). Yet the Buddha also accepted Karma which is a metaphysical kind of causality across lives through reincarnation and offers the escape from this wheel of Samsara (Birth and Death) as Nirvana (cessation). The basic contradiction is how can there be causation when everything is empty? There is no substantive basis to carry the causation, yet the struggle for freedom from Karma is the central drive that pushes Buddhists toward the realization of Nirvana.
To understand this we need to go back to Hinduism. In Hinduism the Self has Being which gives it eternal continuity as Atman. Thus reincarnation is cycles of being for all living things and where you are in the great chain of Being is dependent on what you did in past lives. The reason that this exists in Hinduism is because it prevents the Gods from being blamed for ones fate in ones life. In other words it turns the responsibility for ones fate back on oneself. This argument that deflects responsibility from the gods has the and puts it in the individuals own past history, which they cannot control, means that fate becomes something one has manufactured oneself, and therefore there is no reason to pity someone who has brought their fate back on themselves from their own activity across infinite lives.
Ironically this is what Nietzsche called Eternal Return. Eternal Return for Nietzsche was a measure for the worthwhileness of life that was not dependent on any transcendental like God. Notice that if the Gods are not responsible for Fate then really they are not needed anymore. Nietzsche said that we should live our lives such that if we do things in our life in such a way that if we were to live our lives over eternally we would not regret or get bored with what we have done. This is sort a kind of Golden Rule for oneself that does not involve our relation to others. It is a basis on which to judge our lives that depends on no transcendental entity, but merely timelessness over multiple reincarnations. Karma is the other way around because it says that we will be in different kinds of lives with different fates in those lives depending on what we did in other lives, and the reason that can happen is that there is the Substance of Being that guarantees the continuity of the Soul. Nietzsche converts this into a speculative pure repetition that does not need Karma but instead sees existence as a kind of repetition compulsion. Zizek says that the great discoveries of Freud and Kierkegaard was their views of the centrality of repetition. And so we can see that Nietzsche also has a part to play in the comprehension that repetition has some interesting repercussions as we see in Deleuze’s Difference and Repetition.
Now we can see that in Hinduism the Gods have really become irrelevant in someway because they have given up their control of the fates of men, but also we can see that in Hinduism there is an infinite weight of Being that each self carries with their own determination of their own fate across many lives. It is this infinite weight of Karma on individual human beings that Buddhism attempts to solve, by saying that the Continuity of Being (Sat) does not exist and the self is empty, and the realization of that brings about Nirvana or the cessation of the wheel of birth and death. Buddhism could not solve the problem for Hindus of the infinite pressure on them for their fate if they denied Karma any reality, if the solution of Nirvana (escape) is to be real, the problem (Karma) has to be real. And so this reality of Karma as a problem that gives rise to the reality of Nirvana as a solution go hand in hand. But because the solution is based on the realization of the emptiness of the cycle itself, but also because it is clear that life goes on after reaching Nirvana until ones death (Pari-nirvana) then the very basis for Karma is negated and yet it is accepted as real because otherwise Nirvana its cessation could not be real. Solving this enigma have kept Buddhist philosophers busy for centuries. And we can learn a lot about our own worldview, which is there worldview by studying their answers to this problem. It is basically a problem that only comes up in the Indo-European worldview with Being, and so the fact that Buddhism is an offshoot from the Hindu worldview means that Buddhism by providing an answer to a problem within the Indo-European worldview takes some of the Indo-European worldview into itself even though it is trying to leave Being behind. Saying that Being does not exist still calls attention to it, and thus does not escape its traces completely. What happens is that despite the rejection of Being, Buddhism remains with traces of Nihilism within its core despite its focus on non-duality. Once Being arises you cannot just immediately return to existence without carrying some of the infection of maya, dunya, dukkah with you back into existence. In this sense there is no direct way our of Being once you have become ensnared in its illusions. Because if this there is great doubt that many Western practitioners of Buddhism ever actually get out of this maze, but in most cases they remain in some sort of rarefied self-delusion. But on the other hand because Buddhism arises directly from the Indo-European worldview of Hinduism it is also perfectly applicable to the Western worldview and thus it is a genuine path toward non duality for Westerners who want to escape the duality of existence emphasized by Western culture throughout its history. However, because this way comes from the Indo-European worldview it is particularly suited for us as Westerners but also it does itself not escape completely the problematic of the Western worldview either particularly its nihilism. Buddhism remains fundamentally nihilistic in spite of its seeking nonduality as a state of existence. And in fact as I say in another answer it in fact uses nihilism of the worldview against itself to provide the leap to Nirvana. So Buddhism is essentially selling us our own snake oil back in different bottles believing that two wrongs do make a right, but unfortunately this is not exactly true and the slight asymmetry causes us not to actually be able to return to existence unsullied by Being.
Now that we have some inkling of the problem that Buddhism attempts to solve, we need to understand the solution. Buddhists themselves realized fairly quickly that the Buddhist goal of Nirvana had the flaw of Selfishness, in other words I sought to become an Arhat and leave Samsara and do not mind if others continue to be ensnared. So it was realized fairly soon that another ideal, that of the Bhodhisattva was actually higher because it did not carry the taint of selfishness that could be posited of the Buddha’s positing Nirvana for oneself alone as the goal. The rise of this higher goal of the Mahayana, by being someone who swears to leave the circle of birth and death last after helping all others escape, appears lower on the scale from Buddhahood. Mahayana is the greater vehicle because it takes everyone to Cessation (not just one empty self at a time), and the holiest are those that wait the longest to enter the state of cessation. Another problem in early Buddhism that Mahayana solved was the fact that early Buddhists and probably the Buddha said only the Self was empty but there were about a hundred other dharmas (tattvas) had real Being. Eventually it was realized that for Buddhism to be self -consistent all dharmas had to be empty. As time went by Buddhism step by step erased the various inconsistencies in early Buddhism and in the process Buddhism became a very sophisticated philosophical approach to existence as nondual. But this nonduality was approached on the basis of a fundamental duality in the nature of truth. There are two truths, one is that of the mundane world, and the other is the world of enlightenment where nirvana is realized by the individual who then comes back into the world and lives as an enlightened being. The fact that there are these two truths, mundane and super-mundane is a fundamental belief of Buddhism. But it is no wonder that eventually a higher kind of Buddhism would come along which would challenge the two truths. And in fact there were several of these, the most interesting of which is DzogChen of Manjushrimitra and Mipham. Manjushrimitra turns Nagarjuna’s logic back against Buddhism producing a second order heresy that denies the two truths, and point out its dualism and nihilism. DzogChen is considered the highest form of Buddhism by the Tibetans. It is a kind of Buddhism that leaves Buddhism behind and is practiced by the Bon (in Tibet like the Taoist, Shinto) as well as the Buddhists. In DzogChen we come full circle finally and return to a pristine state, after carrying the infection of Being over into the Nondual on the way our of it. And this is a fundamental lesson. Getting out of Maya, Dunya, Dukkha is not so easy as just taking a nondual stance toward existence, one must get rid of the traces of nihilism that are left over from being in existence as well.
So there is actually four different states:
- Taoism – Void existence prior to the introduction of Being.
- Duality within a World suffused by Being created by Indo-Europeans uniquely
- Non-Dual Emptiness that is still nihilistic even without Being in Buddhism
- The extraction of nihilism from nondual emptiness in DzogChen’s manifestation.
The key point is that all these are different states and the fact that DzogChen negates the nihilism still endemic to Buddhism despite its claims to nonduality of emptiness does not mean that the primordial void has been returned to in the pristine way in which we departed from it when we created Being. However the sate that DzogChen proposes appears very similar to the state of Void in Taoism. One way to talk about this is to realize that Taoist Void and Buddhist Emptiness are different from each other and that they are in fact dual-nonduals. What DzogChen gets at is a deeper nonduality of manifestation prior to the distinction between emptiness and void created by the institution of Being.
I think the Shakyamuni Buddha and the history of Buddhism producing enlightened Beings as we can see from their works that are left to us and perhaps direct perception upon meeting them, is existential evidence that Nirvana can be obtained by Human beings. However, Nirvana itself is not the goal for Mahayana Buddhism but instead the saving of all Human Beings from Samsara. So the escape from the world goal has been replaced by an indirect goal of helping others to escape from the wheel of Samsara and then escaping last, using one’s incarnations to work toward the salvation of everyone from Dukkah. Those who settle for the lesser and more selfish goal of Nirvana are called Arhats, and they are seen as a necessary step toward the Bodhisattva ideal, but their perfection is limited by their desire to leave the world before others. It is the difference between the Crew and the Captain of a sinking ship. The crew escape as they can but the Captain is suppose to make sure everyone else is off the ship before they abandon ship. The Buddha and his pari-nirvana was necessary for the gaol of complete enlightenment to be manifest in the world, but soon after that it was realized that a higher goal for those who claimed self-lessness (an-atman) was to vow to be last of the sinking ship of this world.
As for how to attain Nirvana take your pick of the many ways to enlightenment that appear in Buddhism. In Buddhism one always says that a particular path is just a little more right than the others, in other words they are all right, but some are more right than others in the view of their adherents.
But as I have said in other posts, Enlightenment in Buddhism has all the trappings of a sophistry, because it is a way of tricking oneself into giving up the self, by becoming completely committed to the goal of achieving enlightenment and then realizing that this goal and the self that pursues it are both empty. So basically enlightenment as being as you are, before you set out to become enlightened. However, the journey is everything, and the two states are not actually in practice the same although they are theoretically the same. There is an asymmetry between the state prior to the seeking of enlightenment and the state after achieving it, even though the two ideally are exactly the same.
Going back to our analogy of the sinking ship, it is as if you invested all of your self in the goal of achieving enlightenment and when you realize that both the self and the goal are empty, then the self, as it were goes down with the ship because there is no escape once one has fully committed to the project of becoming enlightened. One merely realizes one day that ordinary consciousness is in fact enlightenment. This is like the realization that although everything at a macro scale is ruled by entropy, the actual atoms out of which things are made are eternal and suffer no entropy. These are two views of things that are very different. From the point of view of Entropy everything is suffering the dukkaha of disorganization over time which causes pain and suffering and eventually death in living things. But from the point of view of non-entropy, what everything is made up of at the atomic level is eternal, and suffers no entropy. And thus if you consider yourself as an aggregate and in continual flux there is in fact only perfection that lives on eternally everywhere, and when your cells turn over in your body, or you die actually nothing happens, the same atoms migrate within the universe and get caught up in other beings in an endless cycle because the constituent atoms are eternal, unless they happen to fall into a supernova or blackhole or some other physical process that causes their elemental nature to change. So the ship goes down, and the sailors and captain become part of the sea, but the sea goes on indefinitely.
Now my point in this answer has been that the realization of emptiness of self and all things, is only a small part of a larger story which includes the fact that although Buddhism gets rid of Being, it does not get rid of the Nihilism inscribed in Being completely. This is not to say that Buddhism is Nihilistic because no nondual way is nihilistic as long as it shows us how to make non-nihilistic distinctions, i.e. is genuinely nondual. But structurally there is still a dualism affirmed by Buddism in spite of its affirmation of nonduality and that is the two truths. What Manjushrimitra does is critique Buddhsim in the way that Nagarjuna critiqued Dualism previously. It turns out that Buddhism is susceptible to that critique, and in fact the state of emptiness is not the whole picture because it has a dual which is the Void which is prior to the arising of Being, such as we see in Taoism and presumably Shinto, and Bon too originally, where nature is seen as the measure of all things even humans and their consciousness and their society. The nondual version of this is called Wu Wei. Since there is no Being in Taoism as expressed in Chinese there is no emptiness. At first the Chinese thought that emptiness and void were the same thing. But eventually they learned that they were different as they got to know Buddhism better. And then after that they attempted to synthesize the two. An excellent example of this is the poetry of Stonehouse translated by Red Pine (http://www.kyotojournal.org/interviews/redpine.html), where there are empty lines interspersed with void lines in the poetry which is a really amazing thing to read and try to understand the difference between void and emptiness as defined by the hermit poet who was zen master and taoist both.
The fact that there is a difference between emptiness and void can be understood in terms of Domain Walls in Physics in which there are differences between different regions of empty space when it is considered to act like a Bose-Einstein
Condensate. We can also understand it mathematically as the difference between the line prior to the one from which a Pascal Triangle arises, and the space between the ones which is empty within the triangle. Undifferentiated space outside is different from differentiated space inside, and especially when the inward space is seen as the substrate of consciousness in itself. So once we realize that emptiness and void are different then we can see how the DzogChen move of Manjushrimitra does not necessarily take us back to the primordial void, but rather takes us down to another deeper level of nonduality in which the difference between emptiness and void, inward and outward is lost, or better has not been established yet. So Manjushrimitra hints at the fact that there is a deeper nonduality beyond the dual non-duals of emptiness/void which are straited and unstraited. This question of the deeper nonduality is also raised in Tien Tai and Huan Yen Buddhism in different ways. It is also raised when we consider the difference between the heresies of Buddhism and Jainism. It is my theory that Mahayana buddhism arose out of the combination of the views of nonduality of these two heresies. That is probably wrong but it is an interesting thought.
This begs the question how many layers of these higher logical types of nonduality are there? This is of course an open question. Where we see this addressed is not so much in DzogChen which seems to have lost its way until Mipham but in Islam, the nondual heresy of the Western worldview which develops within Sufism a way of looking at these deeper levels of nonduality calling them Sifat and Dhat. But once we understand that reference we can read it back into other Buddhist paths and see that there are probably many of these paths that are misunderstood because they are actually refering to a different meta-level of nonduality than they were originally thought to refer to in a theoretical world in which there is only one kind of nonduality, i.e. emptiness, or there are two as in later chinese buddhism where Taoism and Buddhist ways are distinguished and synthesized.
To obtain these deeper states of nonduality you must first understand that they exist from a theoretical point of view, and this negates the idea that emptiness is no-mind because we need our rational faculties as well as our sensory faculties to understand nonduality. Non-duality is defined by the tetralemma which is a logical structure, it is what is other than the four logical positions of the tetralemma. Here we can use some ideas of Kant to make the distinction between conceptual understanding and pure intuition. Synthetic Aprioris like space and time are pure intuitions in Kant. So we can think of prajna as a pure intuition as well. While Kant is talking about physical space, which is identical to the void, Buddhism is taking about the emptiness of consciousness and considers physical space an illusion. From a Buddhist perspective there is also a synthetic apriori that is inward that is received from the whole of consciousness experienced as white light without any interference from substance (i.e. the illusory perduring of Being). It is like the difference between ether and what we think of as empty etherless space of modern physics. When we go beyond logic the only place to go is a singular particular which is spacetime outwardly and consciousness inwardly. Formally the point of view of Buddhism and Taoism these two are completely different. But DzogChen has the mantra Mind is like Space. In other words they are pointing out that space and emptiness of consicoiusness are really the same thing in some sense, and thus inward and outward nonduality are really the same manifestation. Void is prior to the arising of the One (what Badiou calls the Ultra One that arises to close off the Multiple), and emptiness is after the repackaging of the Multiple as the Manifold in Experience. But in terms of manifestation they belong together as the Same (to use a term of Heidegger from Identity and Difference.
This difference that makes a difference (Bateson) between the two kinds of nonduality, striated and unstriated, becomes more interesting when we realize that this difference is marked by Ultra Being, the singularity of the externality of Being at the fifth meta-level of Being. This is where we realize that Being and Existence with its two interpretations (empty and void) are interleaved and inseparable. The Indo-Europeans have merely substativized attempting to render it (Maya, Dunya, and Dukkah) perdurant by creating the artificial Being/Having concepts within their language. It is only knowledge that has this kind of perdurence in experience. The Indo-Europeans tried to give the objects of knowledge the same kind of persistence as knowledge itself with the idea of Being, the first and deepest ideology.
When we realize that there are different higher logical types of Nonduality, then we can think that nonduality is infinitely deep as Heidegger feared when he uncovered the meta-levels of Being. But just as with Being the finitude of this series is also true of non-existence. However, just as the meta-levels of Being are harder and harder to think (Parmenides said Being and thinking are the same), so to the different levels of Non-existence are also qualitatively different from each other and harder to explain in language, and harder to point to once achieved. But essentially from a theoretical point of view one must delve into the various higher logical types of existence via negation or non-existence, because existence itself is unstriated in relation to Being which is striated by its meta-levels. So it is only via the striations of negation that the higher logical types of nondual existence can be explored.