Non-dualism from Shankaracharya to Nisargadatta Maharaj
No mental speculation is possible on what is meant with this clear and absolute indication of reality.
The Non-dual concept faces the scene of human thought five thousand years ago, in the last portions of the Vedas (Vedanta) called Upanishad, which states: "From the One rises the One, if from the One remove the One only the One remains ". In the VIth century BC the Indian civilization is prey to empirical and mathematical depressions, at that time the Vedantic subtleties were shelved and replaced by ritual formalisms, theisms and sophisms of various kinds, for this reason the Buddha's coming marked a revival of the authentic spirit in the attempt to overcome spiritual materialism.Thus it happened that the Buddhist doctrine of the "sunyata" (emptiness or void), in which the substance and value is denied to the forms and manifestations of the world, brought attention to the percipient.
The description of the empirical existence as origin and source of suffering restored stamina and impetus to the realization of pure spirit, but already in the 5th century AD. the internal diatribes of the various Buddhist systems were deteriorating the cleansing of the original teaching of the Buddha.And it is precisely in that historical context that the great sage Adi Shankaracharya appeared on the scene, who from an early age began to bring Hindu society back to understanding the One without a Two. He did this by indicating the daily spiritual practice of renunciation of dualistic thought forms: "Neti ... Neti" (not this ... not this).
The great movement that emerged is still alive and well and has therefore produced countless essays referring to this line.It can not be said that Non-dualism can be perfected, but as regards the descriptive way we can say that this statement is appropriate in the case of Ramana Maharshi, the sage of Arunachala, the solitary sacred mountain in Tamil Nadu, where he lived in permanent retreat in the first half of the last century. Ramana is universally recognized as the popularizer of the Non-dualist Advaita beyond the borders of India. He, in the verse X of his 'Forty Verses on Existence' thus states: "There is no separate knowledge from ignorance, there is no ignorance separate from knowledge. Whose knowledge and ignorance are these? True Knowledge is that which knows the Awareness that it knows, which is the basic principle ".
According to the experience of Ramana, there is no separation, and everything is therefore brought back to the Self. This sublime expression of the Consciousness that knows itself has been subsequently explained, in a refined and culturally acceptable way for our speculative mind, by the Indian sage Nisargadatta Maharaj, who in his extreme descriptive simplicity simply stated: "I am That". In the direct realization of the Self there are no descriptions that can adequately convey this ineffable experience, and this is why the denial or refusal of any spiritual assumption and proposition was the characteristic of a last sample of the line, namely U.G. Krishnamurti - the saint who denied every sanctity that was other than the pure state of awareness - exclaiming: "my words are like the braying of an ass ... there is only life that marvelously accomplishes the work". With this signaling the final point of "no return" to empirical dualism.