illustration (attribution, if any possible, is at the end of the article)
Of course, one key to Enlightenment is in realising non-duality, in realising the "right view" of the World as one causal web of inter-dependent processes. A great Tibetan teacher had a good laugh not so long ago when meeting Western scholars (and 'secular' buddhists) who insisted that the Buddha did not teach non-duality! But realising oneness is not enough to be Enlightened…
The classic delusion of most practitioners experiencing such the attainment of non-duality is to believe they're Enlightened.
They're not, they might have ceased a fetter… they might have ceased the "identity view" (sakkāya-diṭṭhi) but that is only the first of the ten fetters according to Theravāda!
Often, the practitioners then cling to this experience of attainment, and to the calm that arises from such a "right view"… and to the very 'relief' of "not having been a practitioner for nothing"!
This might help them to drop the second fetter (doubt in the Dharma) but might also strengthen the third fetter (attachment to rituals): the practitioners easily become zealous, in an attempt to recreate the breakthrough!
Oneness is not Enlightenment
When one truly sees the world as one causal web, when one truly realises one's inter-dependence with everything, there is a moment of blindness! This is not the cessation of ignorance! It is like putting the head under the waves and realising the depth of the ocean, but then the waves are invisible: awareness is different but it lost its original perception of reality to replace it with another, rather than it expanded it.
While one experiences calm and equanimity, one tends not to see the suffering experienced by other parts of the causal web… or one might see it but not to experience compassion… to see the whole as 'perfect' and "everything is as it should be" instead of seeing the struggling parts as opportunities to embody and manifest the clarity attained vis-à-vis causality!
Enlightenment is beyond Oneness
Enlightenment is when you "go back" into the painful world, when you accept that parts of the causal web are suffering even if your 'experiencer' stopped its appropriation process (susceptible of making 'you' identify with the suffering).
These parts have not stopped their own appropriation processes; and you might see through these delusional processes, you might be immune to them, but they're still parts of the causal web (precisely causing… suffering!).
So you step out of the equanimous calm, of the 'observer' stance, of the jhāna you're in… and back into the 'engaged' world.
It doesn't matter whether you're an arhat or not, this is not a karmically back: you attained beyond the existence of suffering and, now, you simply realise beyond the non-existence of suffering.
Theravāda offers one of the most dualistic views in Buddhism, for it unambiguously states that all dhammas are conditioned, except one (nibbana). If you think Buddhism is non-duality, you're contradicting the oldest school and the most primordial suttas…
However, the unconditioned nibbāna is… unconditioned: it does not depend on a beginning, on causes to arise from, nor on a particular direction (towards a particular ending)…
There's nothing "before nibbāna" and nothing "after nibbāna". As the unconditioned dhamma, nibbāna is not dependent on "sustaining conditions", so it is not impermanent (conditioned dhammas are impermanent, not nibbāna).
But if there's no "before nibbāna", what is your nature right now? What do you 'mean' by believing that you're living in saṃsāra?
Mahāyāna phrases this as "nirvāṇa is saṃsāra". It is easy to naïvely oppose this non-duality to Theravāda's duality, but really that's just misunderstanding the Theravādins.
At the end of the day, this is not any worse or better than distinguishing "right views" from 'ignorance', or "right livelihood" from unwholesome tendencies (gplus.wallez.name/UcMtGZaLXAo)! Or for the Zen enthusiasts of non-duality, this is not any worse or better than isolating Mahākāśyapa among all monks in the Flower sermon.
As soon as we talk of how the empty form (manifestation) of nirvāṇa differs from the empty form (manifestation) of saṃsāra, we introduce duality.
It might seem 'wrong', but it is not. This is just moving beyond duality towards oneness, then beyond oneness towards duality! There's no one formulation above the other (gplus.wallez.name/TUTAvQSj9cz).
When going beyond oneness, we can then be at peace when stating that nirvāṇa shares the same plane of existence as saṃsāra, but is a different way to relate to, a different way to engage with the said world.
It isn't a problem to re-introduce duality in 'manifestations' debated at this point, since enquiring was enough to re-introduce the nirvāṇa / saṃsāra duality!
Once duality is back, there's little point clinging to non-dual 'speech', i.e. to rituals (third fetter). We can present "non-duality with discernment" (gplus.wallez.name/F3EAbHBZnTE)! We can talk of the Quiet Mind (koan.mu/quiet_mind.htm) without confusing the cessation of suffering with a cessation of feeling (gplus.wallez.name/86cNVHABTSE).
Once we understand the empty nature of language, the empty nature of narratives, there's no need to fret when talking about nirvāṇa. We just don't confuse what we say with what it is.
Clinging to "nothing can be said about nirvāṇa" is just dualistic anyway, when a lot may be said about everything else! And if "nothing can be said about anything", you're denying your very sentient experience; how wise could this be?!
So… just relax about duality ("versus" non-duality?)! Duality is not the issue, discernment is not issue; clinging is the root-cause of suffering.
Not seeing duality "as it is" causes suffering, but duality itself does not. Not seeing non-duality "as it is" causes struggle, but non-duality itself does not. Clinging to one view (be it subtle and dual) and « I'm right, you're wrong » causes dissatisfaction, but views in themselves do not. Relax! Embody Peace!
Art: © Wendy Ng