Non-duality AND Advaita Vedanta and Buddhism

[tiltbillings]

The Dawn of Tantra; Herbert V. Guenther, Chogyam Trungpa; ed. Michael Kohn, illustrated Glen Eddy and Terris Temple; The Clear Light Series; Shambala; Berkley & London; 1975 pp. 74-76

Guenther: The term advaita, as we use it, stems from Shankara's Vedanta. The Buddhists never used this term, but used rather the term advaya. Advaya means "not-two"; advaita means "one without a second." The conception of "one without a second" puts us at once into the realm of dualistic fictions. Rather than remaining in immediate experience, with the idea of "one" we posit a definite object. This would then necessarily be over against a definite subject, which is the implication Shankara wanted to deny with the "without a second." By saying "not-two" you remain on solid ground, because "not-two" does not mean "one." That conclusion does not follow.

In the works of Saraha and other Buddhist teachers, it is said that it is impossible to say "one" without prejudgment of experience. But Shankara and his followers were forced by the scriptural authority of the Vedas to posit this One and so were then forced to add the idea "without a second." What they wanted to say was that only Atman is real. Now the logic of their position should force them to then say that everything else is unreal. But Shankara himself is not clear on this point. He re-introduced the idea of illusion which had previously been rejected by him. Now if only Atman is real, then even illusion apart from it is impossible. But he was forced into accepting the idea of illusion. So he was forced into a philosophical position which, if it were to be expressed in a mathematical formula, would make absolute nonsense. So intellectually, in this way, it could be said that the Vedanta is nonsense. But it had tremendous impact; and, as we know, the intellect is not everything. But as the Madhyamika analysis showed, the Vedanta formula simply does not hold water. And Shankara himself, as I said, was not completely clear on this point.

In translating Buddhist texts, it is necessary to take great care with the word "illusion." Sometimes it appears in what is almost an apodictic or judgmental sense. This happens especially in poetry, where one cannot destroy the pattern of the flow of words to make specific philosophical qualifications. But the basic Buddhist position concerning illusion, as prose works are careful to point out, is not the apodictic statement made by the followers of Shankara that the world is illusion. The Buddhist position is that the world may be like an illusion. There is a huge logical difference between saying the world is an illusion and saying the world may be like an illusion. The Buddhist position suspends judgment.

So while it has been suggested that Shankara was a cryptoBuddhist, because, in fact, he took over almost the entire epistemological and metaphysical conception of the Buddhists, there remains this very crucial difference.

[tiltbillings]

BUDDHADHAMMA by Phra Prayudh Payutto, Suny, 1995, pgs 64-5:

Many Hindu sages and Western philosophers have tried to explain
the reason why Lord Buddha did not reject the notion of self (atta) or
Atman at the highest level but only rejected some phenomena, such as
those found in the above passage. These philosophers suggest that Lord
Buddha rejected the Five Aggregates and all other phenomena as the self
because the atta that really exists is not composed of the Five Aggregates.
Accordingly, these thinkers have cited many other statements in order to
demonstrate that Lord Buddha only rejected some phenomena as the self,
but he did accept a notion of self (atta) at the highest level, and they have
attempted to explain that nibbana (nirvana) is the same state as this self
or Atman-that is, at the highest level nibbana is atta. While this matter
may be worthy of a larger philosophical discussion, I would just like to
turn to a brief consideration of the ethical importance of this: Common
people, especially those who have been educated to believe in Atman, will
have the inclination to cling to or grab at any notion or form of self (atta)
in order to fulfill a desire that is hidden and deeply imbedded in the mind.
When people are introduced to these principles and discover that they
must lose the latent sense of a self (at the level of the Five Aggregates),
they try to create or build something new to cling to. But according to
Buddhist principles, a person should not let go of one thing only to cling
to something else -- you should not free yourself only to become the slave
of something else. In other words, things that have a self do not exist;
and things that exist, are without self.
The existence of all things in a state of flux or as a flowing current,
all interrelated and interdependent, each the related cause of the other,
each impermanent, subject to dukkha, and without a self (anatta), must
be clarified by an explanation of the principle of dependent origination
(paticcasamuppada).

Monks, whatever contemplatives or priests who assume in various ways when assuming a self, all assume the five clinging-aggregates, or a certain one of them. Which five? There is the case where an uninstructed, run-of-the-mill person -- who has no regard for noble ones, is not well-versed or disciplined in their Dhamma; who has no regard for men of integrity, is not well-versed or disciplined in their Dhamma -- assumes form (the body) to be the self, or the self as possessing form, or form as in the self, or the self as in form.... Owing to the fading of ignorance and the arising of clear knowing, (the thoughts) -- 'I am,' 'I am this,' 'I shall be,' 'I shall not be,' 'I shall be possessed of form,' 'I shall be formless,' 'I shall be percipient (conscious),' 'I shall be non-percipient,' and 'I shall be neither percipient nor non-percipient' -- do not occur to him." - SN III 46

[Fede]

This is what terrifies me.
I barely understand a word of that.

[tiltbillings]

This is what terrifies me.
I barely understand a word of that.

It would probably help to point to what it is that you do not understand. Basically, however, what is being said by the bhikkhu is that rather than deal with the reality of anatta because it is frightening, some people will try to find a truly true self, and the Buddha states that whatever truly true self one might find, it in reality is grounded in the khandhas, making it a constructed impermanent thingie.

As for what Guenther is saying, that takes a little more work. Mostly what he is saying is that an idea of "oneness" actually gets us locked into a duality.

[Fede]

Now see, that's what I understand.

High-falutin jargon is confusing to me.
I'm not saying it's wrong, I'm not saying it should not be like that, I'm not saying it's unnecessary.
I'm merely saying I find it extraordinarily difficult to deal with and digest.
The way you have just put it, is all I need.

And I get it.
And I 'knew' it already. ('knowing' and 'realising', being two different things.... )

Thank you.

[AdvaitaJ]

Tilt,

I presume there was more behind this thread because of the way it just jumps right in with no pre-amble or explicitly stated conclusion. If so, please don't consider the following comments as anything other than interested musings.

As may be surmised, "advaita" has more than a passing interest for me. I heard it defined about forty years ago as "non-dual" and have since read in multiple places the same definition. As a consequence, it strikes me that the reference to advaita being defined as "not two" is likely to be obscure at best.

Being well aware of the sensitivity on a Buddhist forum of advaita by implication suggesting the Hindu concept of unity with the atman, I've thought occasionally about ditching the moniker. However, "advaita" can also just be a word. Non-dual to me implies unity or unification as opposed to the simple "one" or self. So...a search of Access to Insight for "unification" reveals a number of highly desirable Buddhist traits.

Being the rookie that I am, I make no claims for having achieved anything worthwhile, but I will say that when I remember to exert mindfulness and reel in the old auto-pilot, the word that best describes the ways that feels to me is unification. Hence, AdvaitaJ.



Regards: He-who-must-not-be-named

[tiltbillings]

AdvaitaJ: I presume there was more behind this thread because of the way it just jumps right in with no pre-amble or explicitly stated conclusion.

Sure. This is basically a prelude for a few reflections on the idea non-dualism. I have been bumping into it on Zen Forum International, to the extent, I was wondering if I had wandered into a Hindu forum. In reading through a thread such as this I have to wonder, and when I read something such as this:

Mother Theresa sees God in humans, Buddhism sees emptiness in/as all things, Advaita sees Awareness/Brahman in/as all things, the Tao works in/as all things, Love is in/as all things, etc... There is no inside/outside. People get a "warm fuzzy" feeling when they hear (and experience) "nondualism" because their sense of separateness falls away, for the moment. The focus is on connection and wholeness.

what is being missed.

[clw_uk]

It seems to me that the non-dual approach is a bit of a paradox since its concered with the "I" of atman, if there is an "I" there will always be duality, or am i misunderstandng?



Metta

[tiltbillings]

It seems to me that the non-dual approach is a bit of a paradox since its concered with the "I" of atman, if there is an "I" there will always be duality, or am i mis-understandng?

That is part of it.

[floating_abu]

AdvaitaJ: I presume there was more behind this thread because of the way it just jumps right in with no pre-amble or explicitly stated conclusion.

Sure. This is basically a prelude for a few reflections on the idea non-dualism. I have been bumping into it on Zen Forum International, to the extent, I was wondering if I had wandered into a Hindu forum. In reading through a thread sich as this I have to wonder, and when I read something such as this:

Mother Theresa sees God in humans, Buddhism sees emptiness in/as all things, Advaita sees Awareness/Brahman in/as all things, the Tao works in/as all things, Love is in/as all things, etc... There is no inside/outside. People get a "warm fuzzy" feeling when they hear (and experience) "nondualism" because their sense of separateness falls away, for the moment. The focus is on connection and wholeness.

what is being missed.

With all respect, the first instinct was to say - just don't use what is not useful.

Isn't that enough ?



On second thought, explore if useful, but the use of that can only be determined by good ol' tilt

friend

[Ngawang Drolma.]

I am in agreement with Tilt if I understand him correctly. I think that when people start imagining non-duality, intellectualizing and striving for non-duality, and conflating the word with awakening, it's just plain confusing and misleading. Non-duality just can not be described well in conventional language and I don't believe it's meant to be.

Wandering into Madhyamaka I know we have to eventually use the word "illusion." But in everyday terms I'm not sure it's so useful.

Thanks for listening, and I'm not trying to bash my own traditions. These are just my musings.

[Dharmajim]

Tilt:

I'm glad you started a thread on non-duality. For the past nine years I've lead a group that studies the Buddhist Discourses. Recently some participants brought up the non-dual view in a way that implied that Buddhism shared that perspective, as if everyone knows that to be the case. After this happened a few times I offered that I was not a non-dualist. My view is that one can interpret the Buddha's teaching in a non-dual way, but there is nothing that compels such an interpretation.

For the past 20 years or so there has been a wave of non-dual teachers in the west; I refer to them collectively as 'western advaita' because I think in crucial ways their presentation of advaita differs from the Indian version of advaita based on Shankara's teaching. This wave of teachers has been very successful. So much so that it is now widely assumed that non-dual teachings are superior to those that are not non-dual. For example, if person N presents a teaching, and person M says the teachings is dualistic, the response of N, in defending the teaching, will be that it is not really dualistic. N will not respond by saying something like, "So what?" because nearly everyone now accepts the idea that non-dual teachings are superior, the pinnacle, and the ultimate.

I think this assumption of the superiority of non-dual teachings is unwarranted. There are great, and very articulate, spiritual traditions that are not non-dual. Christianity is one of these , Platonism is another, Confucianism is yet another, and there are numerous other traditions that are not world-wide, such as Shinto, that are not non-dual teachings. In addition, most Hindus are not non-dualists and there has been a sustained critique of advaita in Hinduism that I find articulate and worth examining. The Jain teaching is also not non-dual and has successfully resisted and critiques advaita. I would also suggest that the Buddha's teaching is not an example of non-dualism, at least as non-dualism is presented by western advaitans.

Non-dualists tend to ignore the great difficulties that non-duality has as a coherent presentation. First among these is the problem of evil. This difficulty is not confined to advaita (dualists struggle mightily with this topic), but it has a special undermining effect on advaita for if there is really only one reality, without a second, then why is it that evil exists in the world, for if there is really no second, and evil exists, then that would imply that the one reality is evil. To get around this advaitans argue for the illusory nature of appearances and the mind-made nature of ethical judgment. But if appearances are illusory then how is that they can say that appearances are illusory; that is to say they seem perfectly content to use illusory appearances to make their case, thereby relying on the efficacy of cause and effect, when it suits their purposes, while denying that efficacy when it suits different purposes.

A second problem is the problem of manyness. The world of appearances does not support the idea that there is ONLY one reality. If one goes along with advaita that there is only one truly real thing, or essence, or being, then why is it that the world of appearances is differentiated? Whence comes differentiation? Dualists do not have a problem with differentiation. Buddhists do not have a problem with differentiation because it is simply a manifestation of the causal nexus at the heart of Buddhist understanding. But for advaitans differentiation represents a constant presence which undermines the core of their world view.

There are other difficlties facing advaita, particularly western advaita, but I don't want to write a long essay. Again, I appreciate you raising this issue as I think western advaita has been given a free ride for far too long.

Best wishes,

Jim

[pink_trike]

The Dawn of Tantra; Herbert V. Guenther, Chogyam Trungpa; ed. Michael Kohn, illustrated Glen Eddy and Terris Temple; The Clear Light Series; Shambala; Berkley & London; 1975 pp. 74-76

Guenther: But the basic Buddhist position concerning illusion, as prose works are careful to point out, is not the apodictic statement made by the followers of Shankara that the world is illusion. The Buddhist position is that the world may be like an illusion. There is a huge logical difference between saying the world is an illusion and saying the world may be like an illusion. The Buddhist position suspends judgment.
[/size]

It's true. Great care was taken to use the convention of " like".:

---

Excerpts from: Sixty Verses on Reasoning - Nagarjuna

- As cessation is imputed in the extinction of originated entities, the Holy Ones consider cessation to be like a magical creation.

- How can what was earlier originated be turned back? Free from the alternatives of antecedence and subsequence, cyclical existence appears like a magical illusion.

- Those who see the world of existence with intelligence as like a mirage and a magical illusion are not corrupted by the views of antecedence and subsequence.

- Without essence, like a banana tree and a fairy city, the unbearable city of delusion that is cyclical existence appears like a magical illusion.

- The Great Persons who see entities through the eye of knowledge to be like a reflection are not entangled in the mire of objects.

---

Excerpt from the Adoration to the Three Treasures - Nagarjuna

In truth there is no birth -
And thus no cessation or liberation;
The Buddha is like the sky
And all beings have that nature.

...and

The nature of all things
Appears like a reflection,
Pure and naturally quiescent,
With a non-dual identity of suchness.

---

Excerpts from: Seventy Verses on Emptiness by Nagarjuna

- Compounded objects and events are like a fairy city, an illusion, a mirage, a bubble of water, foam and like a dream and the circle of the whirling fire-brand.

[bazzaman]

.

[christopher:::]

AdvaitaJ: I presume there was more behind this thread because of the way it just jumps right in with no pre-amble or explicitly stated conclusion.

Sure. This is basically a prelude for a few reflections on the idea non-dualism. I have been bumping into it on Zen Forum International, to the extent, I was wondering if I had wandered into a Hindu forum. In reading through a thread sich as this I have to wonder, and when I read something such as this:

Mother Theresa sees God in humans, Buddhism sees emptiness in/as all things, Advaita sees Awareness/Brahman in/as all things, the Tao works in/as all things, Love is in/as all things, etc... There is no inside/outside. People get a "warm fuzzy" feeling when they hear (and experience) "nondualism" because their sense of separateness falls away, for the moment. The focus is on connection and wholeness.

what is being missed.

What is being missed, is context. The link Tilt provided is to a discussion thread in our "Friends Along the Way" subforum, over at ZFI, which was created for "Dharma discusions and ecumenical common ground with other traditions of the world, esoteric, nondual, psychology, quantum physics, etc.". The quote (of mine) above (given out of context) is from a discussion where the OP asked about the differences between Zen, Christian, Advaita and other non-dual approaches...

Nonduality, btw, is something Buddhist teachers have talked about as well, its not something associated only with Hinduism...

"If you seek reality and you think that it has to be taught to you by a Tibetan Lama, that you have to look for it outside yourself, in another place - maybe Shangrila! - then you are mistaken. You cannot seek reality outside yourself because you are reality... You have to see that your attitudes, your view of the world, of your experiences, of your girlfriend or boyfriend, of your own self, are all the interpretation of your own mind, your own imagination. They are your own projection, your mind literally made them up. If you don't understand this then you have very little chance of understanding emptiness. This is not just the Buddhist view but also the experience of Western physicists and philosophers - they have researched into reality too. Physicists look and look and look and they simply cannot find one entity that exists in a permanent, stable way: this is the Western experience of emptiness.. If I told you that you are nothing, you are zero, that you are nothing that you think you are, then you would be shocked. "What is this monk saying?" But what if I say that it is the truth! In fact you are non duality, non self existence. You do not exist, relatively or absolutely, as you think you do. If you really understood this then you would become more realistic and you would really gain satisfaction and peace. But as long as you hold on to the fantasy, concrete conception of yourself and project this wrong conception onto your environment, then no way will you understand reality... "
~Lama Thubten Yeshe, 1983

"The only true joy on earth is to escape from the prison of our own false self, and enter by love into union with the Life who dwells and sings within the essence of every creature and in the core of our own souls."
~Thomas Merton

"Our usual understanding of life is dualistic: you and I, this and that, good and bad. But actually these discriminations are themselves the awareness of the universal existance. "You" means to be aware of the universe in the form of you, and "I" means to be aware of it in the form of I. You and I are just swinging doors..."
~Shunryu Suzuki, Zen Mind, Beginner's Mind.

Q: If I am already fundamentally free, then why do l not feel as though l am free?

A: The only obstacle is your belief that you are an independent entity. That is the only obstacle. You are stuck in this belief. It belongs to a personality invented by society, education, experience, beliefs, second-hand information and all kinds of reading. You have identified yourself with this fictitious “I” and you live from this point of view. You look at and contact the surroundings from this viewpoint. Because the personality is an object like any other, you live in object-object relationship... Why put yourself in the cage of a fraction? You are the whole, the global.
~Jean Klein, Advaita teacher
A talk in Delphi, 1990

[Dharmajim]

Greetings Christopher:

The kind of quotes you offered on non-duality illustrate what strike me as some of the shortcomings of that approach, particularly as it is offered in the west. The idea that the "only" obstacle to "freedom", which I take to be a stand-in for "awakening" or "liberation", is one's belief makes the whole spiritual enterprise a completely mental affair. In turn this leads to a focus on having some kind of liberative experience; again a mental experience. This, in turn, undermines genuine spiritual work on the everyday level such as "right speech", or "right livelihood".

For a number of years I was a Chaplain at a Prison for the Criminally Insane. The view that the only obstacle to freedom that these inmates had was their incorrect idea is laughably incoherent. No one, and I mean no one, at this facility would have taken such an analysis seriously (with the possible exception of delusional schizophrenics who already thought they were divine). My view here is that western advaita is a teaching that is designed to appeal to an extremely narrow class of people, a class of people who are highly privileged, highly educated and have an abundance of leisure time. This is a very select group. Western advaita, because of its focus on the mental, has nothing to offer the mass of ordinary people, let alone those who are more seriously afflicted either by the circumstances of their birth, their heredity, or fate. It is an extremely elitist approach to spirituality.

I don't mean to sound overly harsh; there are non-dual teachers I admire. But to repeat from my previous post, non-dual teachings in the west, particularly in the truncated form which most westerners advaitans teach them, have gotten for far too long a free ride which I think is unwarranted given that many of their assumptions are highly dubious and given that the results of their teachings do not seem to bear fruit in any significant way that I have been able to observe.

Sincerely,

Jim

[Jechbi]

... it is now widely assumed that non-dual teachings are superior to those that are not non-dual. For example, if person N presents a teaching, and person M says the teachings is dualistic, the response of N, in defending the teaching, will be that it is not really dualistic. N will not respond by saying something like, "So what?" because nearly everyone now accepts the idea that non-dual teachings are superior, the pinnacle, and the ultimate.

I think this assumption of the superiority of non-dual teachings is unwarranted.

Thank you for saying this! The emporer is, indeed, wearing no clothes.

... if there is really no second, and evil exists, then that would imply that the one reality is evil. To get around this advaitans argue for the illusory nature of appearances and the mind-made nature of ethical judgment.

Maybe replace the loaded term "evil" with the more neutral term "dukkha"? Otherwise I think you might be oversimplifying the "non-dual" understanding.

A second problem is the problem of manyness. The world of appearances does not support the idea that there is ONLY one reality. If one goes along with advaita that there is only one truly real thing, or essence, or being, then why is it that the world of appearances is differentiated? Whence comes differentiation?

Avijja?

Dualists do not have a problem with differentiation. Buddhists do not have a problem with differentiation because it is simply a manifestation of the causal nexus at the heart of Buddhist understanding. But for advaitans differentiation represents a constant presence which undermines the core of their world view.

You're right to the extent that lots of folks seem to oversimplify things.

from here:

The truth is one,
there is no second
about which a person who knows it
would argue with one who knows.

[christopher:::]

Greetings Christopher:

The kind of quotes you offered on non-duality illustrate what strike me as some of the shortcomings of that approach, particularly as it is offered in the west. The idea that the "only" obstacle to "freedom", which I take to be a stand-in for "awakening" or "liberation", is one's belief makes the whole spiritual enterprise a completely mental affair. In turn this leads to a focus on having some kind of liberative experience; again a mental experience. This, in turn, undermines genuine spiritual work on the everyday level such as "right speech", or "right livelihood".

For a number of years I was a Chaplain at a Prison for the Criminally Insane. The view that the only obstacle to freedom that these inmates had was their incorrect idea is laughably incoherent. No one, and I mean no one, at this facility would have taken such an analysis seriously (with the possible exception of delusional schizophrenics who already thought they were divine). My view here is that western advaita is a teaching that is designed to appeal to an extremely narrow class of people, a class of people who are highly privileged, highly educated and have an abundance of leisure time. This is a very select group. Western advaita, because of its focus on the mental, has nothing to offer the mass of ordinary people, let alone those who are more seriously afflicted either by the circumstances of their birth, their heredity, or fate. It is an extremely elitist approach to spirituality.

I don't mean to sound overly harsh; there are non-dual teachers I admire. But to repeat from my previous post, non-dual teachings in the west, particularly in the truncated form which most westerners advaitans teach them, have gotten for far too long a free ride which I think is unwarranted given that many of their assumptions are highly dubious and given that the results of their teachings do not seem to bear fruit in any significant way that I have been able to observe.

Sincerely,

Jim

Hi Jim,

I don't know enough about "Western Advaita" as a whole to defend it. I would agree that a singular focus on mental change is limited, especially if not paired with compassionate action. I'm more interested in the implications of nondual ways of thinking in all religious traditions. When Mother Theresa talked about seeing God in all people, or of "Jesus in his various disguises" this was a nondual perspective that had a very positive practical impact on the world...

I do not believe that "freedom" is a simple mental exercise, but do think that the belief in self and other as fundamentally independent is indeed one of the traps most people on our planet wrestle with. As for Western Advaita being a highly elitist and overly intellectual approach, you are probably right. I sometimes feel that there are Western Buddhists who are practicing Buddhism in such a manner, as well.

No one here, of course.

[floating_abu]

Greetings Christopher:

The kind of quotes you offered on non-duality illustrate what strike me as some of the shortcomings of that approach, particularly as it is offered in the west. The idea that the "only" obstacle to "freedom", which I take to be a stand-in for "awakening" or "liberation", is one's belief makes the whole spiritual enterprise a completely mental affair. In turn this leads to a focus on having some kind of liberative experience; again a mental experience. This, in turn, undermines genuine spiritual work on the everyday level such as "right speech", or "right livelihood".

Thanks Jim, some great points.

Your post also brought to mind though the wider underlying point to all this, and that is the belief that Buddhism can be learnt on the internet, or through books only; and/or that coming to an (intellectual) understanding is sufficient.

Perhaps the error in this case however does not lie in the context or format of the teaching - as each format develops/presents its own -- but in the ability of those words to encourage/lead students toward the path of liberation, or alternatively lure students into staying in the cosy nest of agreeement or intellectual "understanding".

That is the risk with explanation at the end of the day. I believe the Buddha's way of teaching to encourage all to strive for liberation and know the truth of this for oneself, however was/is truly magnificent, and we are very grateful for his efforts.



PS I should state that I have not read the teachings/teachers you mention in detail and thus cannot comment on the efficacy or reliability of those therein, I have tended to naturally incline towards Buddhist teachings but can always appreciate the flavours of many traditions inside and outside of our religion.

Again thanks for some great points.

[Individual]

The Dawn of Tantra; Herbert V. Guenther, Chogyam Trungpa; ed. Michael Kohn, illustrated Glen Eddy and Terris Temple; The Clear Light Series; Shambala; Berkley & London; 1975 pp. 74-76

The term advaita, as we use it, stems from Shankara's Vedanta. The Buddhists never used this term, but used rather the term advaya. Advaya means "not-two"; advaita means "one without a second." The conception of "one without a second" puts us at once into the realm of dualistic fictions. Rather than remaining in immediate experience, with the idea of "one" we posit a definite object. This would then necessarily be over against a definite subject, which is the implication Shankara wanted to deny with the "without a second." By saying "not-two" you remain on solid ground, because "not-two" does not mean "one." That conclusion does not follow.

I'm not sure what he says is right. If Pali and Sanskrit are related languages, then they would share the same roots. According to this Sanskrit dictionary, Advaita means "non-duality" and Dvitva means "duality". According to the PTS dictionary, Dvaya means "two-fold" and thus, Advaya means "not-twofold", as he says.

But since the two sets of words seem to be of the same etymological roots, distinguishing them seems weird. Adding the a- prefix is a negation in Pali or Sanskrit. Now, of course early Buddhists didn't speak Sanskrit. But Dvitva also can be translated as "couple" or "pair". So, you could also interpret Advaita as meaning "not two" also. Furthermore, the common usage of language doesn't necessarily follow logic, so it's entirely plausible that Advaya in Pali could mean both non-dualism or monism, in addition to being a description of the Buddhist rejection of both dualism and non-dualism.

Also, I believe some the Advaitins reject monism and dualism as well, by saying that the individual atman (self or soul) is an illusion. The great "Atman" is upheld as supreme ideal, or ultimate, but you have the same notion in Buddhism, regarding Nirvana, the Deathless, etc., although it isn't referred to as Atman. Not referring to it as Atman is a difference, but only a trivial one, really. Both seem to be dialectical monism... Both "self is real" and "self is not real" are refuted as views in favor of direct insight. This disagreement really only arises out of a Theravadin stubbornness to take philosophical positions and conflating the Advaitin Atman with the idea of an existent agent or soul.