Enlightenment in Buddhism and Advaita Vedanta
Enlightenment in Buddhism and Advaita Vedanta:
Are Nirvana and Moksha the Same?[*]
David Loy
p. 65
WHAT MOST distinguishes Indian from Western philosophy is that all the important Indian systems point to the same phenomenon: Enlightenment or Liberation. Enlightenment has different names in the various systems -- kaivalya, nirvana, moksha, etc. -- and is described in different ways, but the similarities among them are great. Perhaps the most significant is the agreement that enlightenment is intellectually incomprehensible; it cannot be understood or attained through conceptual knowledge, because it escapes all categories of thought. Hence Indian philosophy points beyond itself to a realization which transcends philosophy.
This paper will consider one crucial aspect of Indian philosophy: what happens when one attains enlightenment. The experience of attaining enlightenment is not merely one of many aspects which could be examined; it is the most critical one. It is the hinge upon which each metaphysic turns, for in each system it is enlightenment which finally and indubitably reveals the true nature of reality. I shall consider how this aspect is treated in three important Indian systems: Samkhya-Yoga, early Buddhism, and Shankara's Advaita Vedanta.
The issue is this: Since enlightenment itself transcends all conceptual understanding, are these different philosophies referring to the same experience? It is difficult not to suspect this. It may be that there are different types of enlightenment, but it seems more likely that various characteristics are stressed because of the differing metaphysical systems within which enlightenment occurs. For example, Samkhya-Yoga may emphasize the isolation from and indifference to the natural world which kaivalya (lit., "aloofness") brings because it is based upon the ontological dualism of a purusha (pure consciousness) which realizes its distinction from prakrti (everything else). This paper will not attempt to resolve the contradictions between these three philosophies; as metaphysical systems they are irreconcilably different. Samkhya-Yoga is dualistic, early Buddhism may be considered pluralistic, and Advaita Vedanta is monistic. The issue is whether it is possible to understand these various systems as describing the same phenomenon from differing perspectives.
These three philosophies are among the most important metaphysical systems, and they may be considered as representative of Indian philosophy as a whole. But they are representative of something else too. They may be seen as the three main ways of trying to resolve a perennial philosophical problem: the nature of the relation between subject and object.
Samkhya-Yoga is the most radical possible dualism between subject and its object. The separation between the two is so extreme that the system fails because there can be no communication and cooperation between them.
Early Buddhism conflates subject into object. Consciousness is something conditioned, arising only when certain conditions exist. The self is merely an illusion created by the interaction of the five aggregates. The self shrinks to nothing and there is only a void; but the Void is not a thing -- it expresses the fact that there is absolutely nothing, no-thing at all, which can be identified as the self.
Advaita Vedanta conflates object into subject. There is nothing external to Brahman, the One without a second. Since Brahman is a non-dual, self-luminous consciousness, consciousness expands to encompass the entire universe, which is but the appearance of Brahman; everything is the Self.
It should be noticed that the subject-object dualism with which these three systems deal can be expressed as either a consciousness-object dualism or a self-non-self dualism. Although these dualisms are not identical, there is obviously a close similarity between them, and for our purposes they will be treated as equivalent.
Samkhya-Yoga is of course actually two systems, often lumped together because they are almost identical. They are dualistic because they postulate two basic substances: purusha, pure unchanging consciousness, and prakrti, the natural world which encompasses everything else. This is not a Cartesian dualism: prakrti includes all mental as well as all physical phenomena. The purusha is reduced to a pure "Seer" which actually does nothing, although its presence is necessary. In our usual deluded condition we are not able to distinguish between them. Pure consciousness mistakenly identifies with its reflections; so I cling to "my" mental panorama and "my" body and its possessions. The purusha is so attenuated that it is not even able to realize the distinction between itself and prakrti; it is actually the buddhi (the most rarified mental part of prakrti) that realizes the distinction, whereupon the purusha is established in its own nature as solitary and independent, indifferently observing the natural world.
Samkhya-Yoga has been much criticized and its defects are well known. The main problem is that the polarity between purusha and prakrti is so great that they are unable to function together. Purusha is so indifferent and prakrti so mechanical that no cooperation can occur. The common simile to explain their interaction is that of a blind man of good foot carrying a cripple of good eye; but this is not a good analogy because both men are intelligent whereas prakrti is not. The simile would fit better if the cripple had no desire to go anywhere and so says and does nothing, while the blind man literally has no mind at all. Clearly in such a case they would not cooperate, yet Samkhya-Yoga claims that the whole universe evolved out of the interaction of purusha and prakrti.
Whereas Samkhya is a metaphysical system, Yoga deals with the yogic path which one follows in order to attain kaivalya. It is significant that there is nothing within the eight limbs of yoga practice which is antithetical to Vedanta; in fact, the Yogic path actually seems to fit an Advaitic metaphysics better than a Samkhya one. In samadhi, the eighth and highest limb, the mind loses ego-awareness and becomes one with the object of meditation, but this non-dualistic experience is only "as it were" in Yoga, since the ultimate goal of the yogic system is the discrimination of pure consciousness from all those objects it identifies with. But this experience accords very well with the Advaitic aim of "realizing the whole universe as the Self."[1]
Yet what is most significant for our purposes is that the purusha, like the jiva of Jainism and the atmans of Advaita and Nyaya-Vaishesika, is eternal and in its true, liberated form is omnipresent; it has no particular locus, but is ubiquitous, all-pervading. This is peculiar, because one might otherwise expect the purusha to be a small, perhaps infinitesimal point located somewhere behind the eyes. It leads to an interesting set of problems, since there is supposedly an infinity or at least a very large number of completely distinct, unrelated purushas. How can they all occupy the same infinite space without affecting each other? A corollary problem is that each undifferentiated purusha has a relationship with only one particular buddhi (individual mind). Furthermore, each liberated purusha, being ubiquitous, must be coextensive with all of prakrti, yet be completely unaffected by it.
These difficulties could be resolved by (1) conceiving of purushas not as distinct from each other, but as various aspects or reflections of one unitary consciousness; and (2) conceiving of prakrti not as distinct from this unified consciousness, but as an aspect of it. But this, of course, is to transform Samkhya-Yoga into a completely different system, because the root dualism of purusha and prakrti is thereby abandoned. It becomes a monistic system similar to Shankara's.
So the most extreme possible dualism between subject and object fails. The failure, it should be noted, is not incidental to Samkhya-Yoga but is a basic inadequacy; such a radical dualism excludes any cooperation between the two categories.
The nature of nirvana is perhaps the greatest problem of Buddhist philosophy, probably because the Buddha himself refused to speculate on it. His attitude was, in effect: If you want to know what nirvana is like, then attain it. But clearly nirvana does not involve the isolation of a pure consciousness, because there is no such thing in early Buddhism. The unique feature of Buddhism is that there is no self at all, and never was; there are only five skandhas, "heaps" of elements, which constantly interact. It is significant that the skandhas do not constitute a self; the sense of a self is merely an illusion created by their interaction. The Buddha emphasized that one should not identify anything as the self.
Nirvana is probably best characterized as the realization that there is no self, although what that means -- what there is that realizes this -- is unclear. The Buddha compounded the mystery by emphasizing that nirvana is neither annihilation nor eternal life. Clearly this is necessary since there never was a self to be destroyed or live eternally; but it is confusing insofar as our thought naturally tends to fall into the dichotomy of one or the other.
Shankara's Advaita (nondual) Vedanta is generally regarded as having best developed and systematized the main strand of Upanishadic thought, which stresses the identity of Atman and Brahman. Brahman is an infinite, self-luminous (self-aware) consciousness that transcends the subject-object duality. Unqualified and all-inclusive, perhaps its most significant feature is that it is "One without a second," for there is nothing outside it. Hence Atman -- the true Self, what each of us really is -- is one with this Brahman. Tat tvam asi: "That thou art." This is "All-Selfness": "...there is nothing else but the Self." "To realize the whole universe as the Self is the means of getting rid of bondage." "To the seer, all things have verily become the Self."[3]
So the Atman should not be understood as a distinct self that merges with Brahman. To realize Atman is to realize Brahman because they are really the same thing; in fact, the two words are used interchangeably in some Upanishads. One may state, in answer to the Buddhists, that a consciousness, a self, is needed to organize experience, but that turns out to have been Brahman itself, when Brahman is realized -- that is to say, when Brahman realizes its own true nature. The world of multiplicity and change is maya, illusion. There is nothing but the all-inclusive Self: yet this sounds awkward, since the concept of a self seems to presuppose an other, a non-self from which it is distinguished (we will return to this later). So perhaps the term Atman should be rejected as superfluous, because it suggests another entity apart from Brahman. One should not multiply entities beyond necessity.[4]
For Shankara, moksha, liberation, is the realization that I am, and always have been, Brahman; my individual ego-consciousness is destroyed, but not the pure, non-dual consciousness which it was always just a reflection of. It must be emphasized that one does not attain or merge with this Brahman; one merely realizes that one has always been Brahman. Shankara uses the analogy of the space within a closed jar: that space has always been one with all space; there is but the illusion of separateness. This point -- that really there is nothing to attain -- is especially significant because the same is true for Yoga and Buddhism. Regardless of however else it is categorized, one's self (or Buddhanature) has always been pure and unstained. The Yogic purusha is an indifferent seer which was always merely observing, unaffected by pain or pleasure. In Buddhism, there never was a self; it was always just an illusion.[5]
Yet, just as there are passages in the Pali sutras which sound Vedantic, so there are passages in the Upanishads which, on the surface, seem Buddhistic. Perhaps the most famous is Yajnavalkya's instruction to his wife Maitreyi in the Brhadaranyaka: "Arising out of these elements (bhuta), into them also one vanishes away. After death there is no consciousness (na pretya samjna 'sti)...." Maitreyi is amazed by this, so Yajnavalkya explains:
For where there is a duality, as it were (iva), there one sees another.... But when, verily, everything has become just one's own self, then what could one see and through what?... Through what could one know that owing to which all this is known? So, through what could one understand the Understander? This Self... is imperceptible, for it is never perceived. (II. iv. 12-15)
In his commentary, Shankara interprets this passage as meaning that when one realizes Brahman there is no more particular or dualistic consciousness. But perhaps there is the same problem with consciousness as with the self: just as the concept of a self normally presupposes a non-self, so consciousness is usually understood to require an object. In fact it is very difficult to conceive of what consciousness could be without an object, a problem which is of course very much the crux of the issue. In English, for example, all the verbs for consciousness are intentional, normally requiring both subjects and objects ("I am conscious of," "you are aware of," "he knows that").[6] If there is a non-dual awareness without an "I" which has it, and without an object which "I" am aware of, can that be called consciousness? Perhaps either reply, yes or no, could be justified.
It is significant that a duplicate of the controversy between early Buddhism and Vedanta exists internally within Buddhism itself. The Theravadin Abhidharmists analyzed reality into a set of separate dharmas ("elements"), whose interaction creates the illusion of a self and of external objects. Nirvana for them seems to have been the cessation of cooperation among these various dharmas, leading to their quiescent isolation from each other. Since consciousness is conditioned, a result of their interaction, this would seem to be the cessation of consciousness as well.
Mahayanists accepted the theory of dharmas, but not their objective reality; in themselves the elements are unreal because they are relative (shunya, "empty"). There is a higher, absolute truth (paramartha), about which one can say nothing (according to the Madhyamika of Nagarjuna) but which comes close to the pure consciousness of Vedanta (according to the Yogacara "Mind-only" school). The similarities between Mahayana and Advaita Vedanta have been much noticed; they are so great that some commentators conceive of the two as different stages of the same system. Curiously, both Shankara and his predecessor Gaudapada were accused of being crypto-Buddhists, while on the other side, Theravadins criticized Mahayana for being a degeneration back into Hinduism. Later, Ch'an Buddhist master Huang Po wrote a treatise on the "One Mind" which could easily pass as an Upanishad; and concerning his enlightenment the Japanese Zen master Dogen wrote: "I came to realize clearly that [my] mind is nothing other than mountains and rivers and the great wide earth, the sun and the moon and the stars." So the debate between Mahayana and Vedanta often resembles a fight where the two boxers are tied together back-to-back.
Yet there is undeniably a serious difference between early Buddhism and Vedanta: the first says there is no self and the other says everything is the self; there is apparently no consciousness in nirvana, but everything is consciousness in moksha. The fact that these systems are so diametrically opposed here, that one is the mirror image of the other, is suggestive. They are both extreme positions, trying to resolve the relation between the self and the non-self by conflating the one into the other. The not-self of Buddhism swallows the self; the self of Advaita swallows the not-self. But do they amount to the same thing?
Does enlightenment involve shrinking to nothing, or expanding to encompass everything? A hint is to be found in Wittgenstein's Notebooks 1914-1916.
The I makes its appearance in philosophy through the world's being my world. (12.8.16)
Here we can see that solipsism coincides with pure realism, if it is strictly thought out. The I of solipsism shrinks to an extensionless point and what remains is the reality coordinate with it. (2.9.16)
...at last I see that I too belong with the rest of the world, and so OR the one side nothing is left over, and on the other side, as unique, the world. In this way idealism leads to realism if it is strictly thought out. (15.10.16)
Wittgenstein's terms, and the problems he is dealing with in these passages, are naturally different from ours, but they take on a particular meaning in the light of our inquiry into the nature of enlightenment. Early Buddhism may be seen to emphasize the nothing, the extensionless point which shrinks to nonexistence; Shankara emphasizes the unique world which remains. But they are describing the same phenomenon.
It has already been stated that all forms of the spiritual path, including of course Samkhya-Yoga, Buddhism, and Advaita, involve complete non-attachment. One should not identify with any physical or mental phenomenon; in other words, one learns to relax and "let go" of literally everything. In doing so, the sense of self "shrinks to an extensionless point" and when that abruptly disappears -- which is enlightenment -- "what remains is the reality co-ordinate with it." On the one side nothing, not even the extensionless point, is left -- this is the Buddhist void, the complete absence of a self. On the other side remains -- everything, the whole world, but a transformed one since it now encompasses awareness within itself; this is the non-dual Brahman of Vedanta.
What is experienced then is the world without a self, hence it is a transformed world. The familiar everyday "natural" world of material objects was formerly balanced by an ego-consciousness that was supposed to be observing it. The evaporation of that separate consciousness requires a new explanation of what awareness is. The awareness which was previously understood to be' observing the world is now realized to be incorporated within it. No longer do "I," as the locus of consciousness, see something external; rather, the self-luminous nature of the thing stands revealed. This phenomenon could be described either as no-consciousness, or as a non-dual consciousness. Early Buddhism opts for the former, claiming that consciousness is nothing more than all those things that are experienced; Shankara opts for the latter, insisting that all those things are consciousness. Buddhism says there is no self, there is only the world (dharmas), Shankara says the world is the Self. To say that there is no self, or that everything is the self, would also then be equally correct -- or false, depending on how one looks at it. Both descriptions amount to the same thing; what is clear in each case is that there is no longer a duality between an object which is observed and a consciousness which observes it; or between the external world and the self which confronts it.[8]
But why is there nothing corresponding to "Brahman" in Buddhism? Early Buddhism refers not to the One but to a plurality of separate dharmas, which is ontologically lopsided: the self has been analyzed away, but the reality of the world as objective has been left unchanged. Later Buddhism corrected this by making the dharmas relative, hence unreal -- they are shunya, empty in themselves. In Mahayana Buddhism shunyata, "emptiness," not only refers to the absence of a self but also becomes the most fundamental characteristic of all reality; in function shunyata is the category which corresponds most closely to the Vedantic concept of Brahman. But can shunyata be reconciled with the One without a second?
My answer to this is prompted by the remark of a contemporary Zen master, Yamada Koun-roshi. Regarding the true nature of things, he said: "Essentially, there is only one thing...not even one." The implication of this statement is that if there is only one thing, and nothing outside that unity -- no duality of a subject and an object -- then that one would not even be aware of itself as one; the phenomenological experience would be of nothing, or nothing, which is shunyata. Awareness of a self -- of a wholeness -- implies an-other from which it is distinguished; so a child acquires an identity only as he or she gains a sense of what another person is. A thing requires boundaries, limits; it is a thing because it is distinguished from something else. For example, it makes no sense to ask whether the universe exists or not; we know how to inquire whether a particular thing in the universe exists, but what criterion could we use to determine whether the universe itself exists?[9] Because the universe, by definition, is not part of a larger structure from which it can be distinguished, so the universe cannot meaningfully be said to exist. In a similar way, because Brahman is One without a second, it cannot be experienced as One.[10] Brahman encompasses all, hence it is empty, shunya. By definition, then, Brahman is also necessarily infinite in the original sense of "not-bounded" (by anything else), as a sphere would be to an ant crawling on it.
So there are two paradoxes: to shrink to nothing is to become everything, and to experience everything as One is again equivalent to nothing -- although a different sense of nothing. It seems to me that these two points are critical in providing a common ground where the two opposed systems meet. If we accept the possibility of such a nondual consciousness -- something which I shall not try to justify here -- then Buddhism and Vedanta may be seen as describing the same phenomenon from different perspectives. From their different perspectives, different metaphysical systems are derived. But we may still wonder why they opt for different perspectives. Why did Shankara prefer to speak of the One and the Buddha of nothingness?
It seems to me that the answer to this lies in the nature of philosophy itself. In referring to Brahman as One without a second, Shankara tries to describe reality from outside, as it were, because that is the only perspective from which it can be understood as One.[11] And this of course is what philosophy tries to do: to look upon the whole of reality objectively and comprehend its structure, as if the philosophizing intellect were itself outside that whole.
But the Buddha realized that we cannot get outside of reality and describe it as an object; our efforts as well as our viewpoints are inevitably contained within that whole. Thinking and its conclusions are events in and of the nondual world, although they are carried on as if they were outside, an independent and fixed measure. We should remember that the Buddha was not really a philosopher, although we inevitably try to force him into that mold; as he never ceased to insist, he was interested only in leading others to the experience of nirvana. From that perspective, all philosophy is only so many words and conceptual structures; insofar as one believes in them -- clings to those ideas -- they act as an obstruction to enlightenment. Meditation is necessary to learn to let them go. Philosophically -- from the fictional "outside" -- we might say that there is only One Mind which encompasses all, but we must realize that phenomenologically there is no such thing, because such a One Mind could not be aware of itself as a self-contained mind in the sense that each of us is aware of his own mind.
What does this imply about how attaining nirvana/moksha would be experienced? Only fools rush in where Buddhas fear to tread, but the above analysis implies there would not be a sense of merging into the One. Instead, it would seem to be a disintegration, although not an annihilation; rather, the boundaries of my ego-self, which distinguish me from others, would simply dissolve. It would be a complete loss of tension and effort, a relaxation of the whole being. Letting go of everything that was previously clung to, one thereby would become that everything which in fact one always was. According to Samkhya-Yoga, the purusha in its true form is ubiquitous. The arhat, said the Buddha, is "deep, immeasurable, unfathomable, like the mighty ocean." The Vedantic Brahman is an infinite pure consciousness pervading everywhere.[12]
In summary, I am suggesting that the difference between the Buddhist nirvana and the Vedantic moksha is one of perspective. The Vedantic explanation -- that of merging into the One-is a more objective philosophical view. The Buddhist interpretation is more accurately a phenomenological description. But in each case the actual experience is the same.
Such an approach will probably be more pleasing to Vedantins and Mahayana Buddhists, since they can see it as a vindication of their own position. Insofar as Theravada Buddhists have made a metaphysic out of the Buddha's phenomenology, one is happy to discomfort them. But all parties accept that conceptual thinking is part of the problem, not in itself the way to enlightenment. So philosophy too must ultimately be transcended. If one accepts that the goal is to attain liberation rather than to understand it, the original phenomenology of the Buddha himself seems the most profound approach. Philosophy tries to view things externally, but ultimately it must fail. As Archimedes had no platform from which to move the earth, so our intellects have no objective external place from which to comprehend it.[13]
* This paper is part of a Ph. D. thesis on "nonduality" which will be submitted to National University of Singapore. My colleague. Dr. Robert Stecker, kindly offered much useful advice on earlier drafts.
1. Pertinent to my argument is the fact that the paths to be followed (sadhana) in order to attain enlightenment are remarkably uniform among all the Indian systems: each requires a foundation of moral purification leading eventually to similar meditation practices. The various paths all involve non-attachment to all physical and mental phenomena, so that the actual process of following the path turns out to be much the same in each case.
2. See also Gradual Sayings, I. 8 in Anguttara Nikaya.
3. Chandogya Upan., VI, viii, 7, trans. Nikhilananda (New York: Harper, 1964); Shankara's Vivekachudamani, trans. Madhavananda (Calcutta: Advaita Ashram, 9th ed., 1974), slokas 226, 339; Isa Upan., 7, trans. Nikhilananda.
4. Although the two terms serve a function, since they emphasize different aspects of the Absolute: Brahman, that it is the ultimate reality; Atman, that it is my true nature.
5. The same point is made in the Oxherding Pictures of Zen: the 9th Picture is "Return to the Source," but in doing so one realizes that one never left it.
6. The primary Sanskrit word for consciousness, "vijnana" (Pali, "vinnana") is formed by adding the prefix vi to jnana, "knowledge." Vi- "expresses separation, privation, dispersion (asunder, apart, off, away, without, etc.)" (Macdonell, A Practical Sanskrit Dictionary, Oxford Univ. Press, p. 279). The English word "consciousness" is derived from the Latin verb scire, which means "to know" but originally meant "to cut or separate one thing from another." Dualism seems inherent to both terms. In contrast, prajna is often defined as that knowing in which there is no distinction between the knower, the known, and the act of knowing; the suffix pra- means "to spring up [by itself?]."
7. The Japanese Zen master Dogen: "To learn the Buddhist Way is to learn about oneself. To learn about oneself is to forget oneself. To forget oneself is to perceive oneself as all things. To realize this is to cast off the body and mind of self and others." ("Genjo-koan," from the Shobogenzo).[/b]
8. It is evident why these should be the two ways of trying to describe non-duality. Our usual experience is dualistic (self and non-self, consciousness and its object), and hence so is our language. Naturally an attempt to express the non-dual experience in ordinary language will tend to eliminate one or the other term. So mystical experience is usually classified (e. g., Rudolf Otto's Mysticism East and West) into two sorts: the "inward way" of withdrawal and the "outward way" of merging into the One.
9. "Exist" is from the Latin ex + sistere, "to stand out from."
10. "This point is the key to understanding one of the crucial aspects of Shankara's system, the relation between Ishvara (a personal God) and Brahman (the impersonal Absolute). Most metaphysics opt for one or the other, but Shankara insists there are both. Ultimately, however, only Brahman is real. "Brahman reflected in maya is Ishvara; Brahman reflected in avidya is jiva." The apparent contradiction between Ishvara and the individual self is the result of ignorance and superimposition. Ishvara is the appearance of Brahman to the individual self, but this last bit of subject-object duality is still illusory; when ignorance and illusion completely disappear, there is neither Ishvara nor self. Shankara is saying something quite extraordinary: God is God only in relation to man; when the two finally dissolve back into each other, there is only Brahman. To realize God is to become aware of a consciousness pervading everywhere; to become Brahman is to realize that that is my consciousness.
The German mystic and philosopher Meister Eckhart made a similar point in distinguishing Deus (God) from Deitas (Godhead). The pure, empty Godhead, he maintained, is infinitely higher than God Himself.
11. Of course this objective description of Brahman should not be confused with the actual nondual experience "of" Brahman.
12. After this initial experience of "returning home," would the state of nirvana/moksha be blissful or not? This is an important controversy. In Yoga, the liberated purusha is indifferent to both bliss and pain; apparently no emotional characteristics are applicable. Yet the true Self is by no means emotionally neutral in Vedanta: Brahman is Satchitananda, Existence-Consciousness-Bliss Absolute; all phenomenal happiness is but a pale reflection of this ultimate joy.
Without attempting to resolve this issue, let me point out two passages that suggest these positions might not be irreconcilable. "Then they said to him: 'Brahman is life (prana). Brahman is joy. Brahman is the void.' Then he said: 'I understand that Brahman is life. But joy and void I do not understand.' They said: 'Joy (ka) -- truly, that is the same as the Void (kha). The Void -- truly, that is the same as Joy.'" (Chandogya Up., IV. x. 4-5) In one of the Pali sutras the arhat Sariputra, in answer to a similar question, says "That there is no sensation, is itself bliss." What this means is unclear, but the parallel is certainly significant.
13. There is another significant disagreement between Vedanta and Buddhism, reminiscent of the Presocratic contrast between Parmenides and Heracleitus: whether reality is unchanging Being or impermanent Becoming. Shankara exemplifies the extreme substance-view: universal and static Brahman is the only Real; the changing phenomenal world is hence unreal maya, just the illusory appearance of Brahman. In complete contrast, early Buddhism provides the extreme modal-view: Reality is dynamic and momentary, objects are analyzed into the interacting and constantly changing dharmas -- attributes which inhere in no permanent substance. (T. R. V. Murti, The Central Philosophy of Buddhism, p. 11.)
But, just as the elimination of the subject transforms the object (and vice-versa), so one cannot eliminate modes completely without transforming the very notion of substance, and vice-versa. In denying the reality of all changing attributes, Shankara ends up defining substance so narrowly that it ceases to have any meaning. Nothing can be predicated of Nirguna Brahman, and it can only be approached through the via negativa of neti, neti: "not this, not this..." Although Shankara would deny it, Brahman ends up as a completely empty ground, a Nothing from which all things arise as its ever-changing appearance.
In a similar fashion, the early Buddhist elimination of all substance gives the dharma-attributes nothing in which to inhere. As the result of a necessary dialectic Mahayana Buddhism ended up hypostasizing shunyata, the emptiness which is the true nature of all things (and which the later Bhutatathata schools saw as the creative source from which all things arise). As Murti points out, an internal dynamic in each tradition led to the postulation of a nondual Absolute (p. 12).
There is still a difference of emphasis. The Nirguna Brahman of Advaita cannot be characterized, but Saguna Brahman is most essentially pure cit, nondual consciousness; whereas Buddhism speaks of nirvana as realizing the emptiness of everything. It is significant that the Atman of Vedanta is not self-conscious in the Cartesian sense: "...He is never thought, but is the Thinker; He is never known, but is the Knower. There is...no other thinker but Him, no other knower but Him." "By what could one know the Knower?" "You cannot know that which is the knower of knowledge." (Brhadaranyaka Upan., III: 7.23; II: 4.14; III: 4.2) Shankara explains: "That which is unknown can be made known and requires proof, but not the self [the knower]. If it be granted that the self requires proof, then who will be the knower [because the self becomes one of the knowables, and without a knower there can be no application of proof]? It is settled that the knower is the self." (Atmajnanopadesa-vidhi, IV, 10)
But such a self that can never be experienced, because by definition it is the experiencer, can be described just as well as shunya, empty -- not however a nihilistic emptiness (Shankara's mistaken criticism of Madhyamika) but a shunyata which will be cherished as the Buddhanature essence of all being.
