Buddhism has not proved the truth of Nonduality. There is no doubt Buddha pointed out unreality of the world. +

Dalai Lama said:~  Buddhism need not be the best religion though it is most scientific and religion and inquisitive. But Buddhism has no answer to certain questions like the existence of Atama [Soul] and rebirth.   Dali Lama said that as an individual he believes in rebirth as he had come across a few cases of rebirth.  Modern science, Dalai Lama hoped would unearth the mystery behind the rebirth. (In DH –dec-212009-Gulbarga).

Buddhism has not proved the truth of Nonduality. There is no doubt Bhagavan Buddha pointed out the unreality of the world. He told people they were foolish to cling to it. But he stopped there. He came nearest to Advaita in speech but not to Advaita fully.

Bhagavan Buddha told people they were foolish to cling to it. But he stopped there. He came nearest to Vedanta in speech but not to Vedanta fully.

Only when we independently search for the truth without religion and its doctrine then we will be able to realize the truth beyond form, time, and space.

Buddhism says Soul (Atma) does not exist because it is limited to form alone and stopped there.

Buddhism says ~ “All things are illusory and nothing exists.  However, Advaita avers that it is not so.  It says that the universe, of course, is illusory, but there is Brahman (consciousness), that exists, forming the very substratum of all things (illusion or universe)”.

Sage Sankara disagrees with Buddhists who say, there is nothing - a nonentity. Sage  Sankara believes there is some reality, even though things are not what they appear to be. If one knows the truth, he will know what to do to find inspiration for action.  The seeker of truth‘s subject is to know what is it that is Real.

Unless one exercises his Buddhi--reason--there is no chance of getting the ultimate truth or Brahman.   

Sage Sankara Advaitic wisdom starts where Buddhism stops. Sage Sankara declares the universe, of course, is illusory, but there is Brahman (consciousness), that exists, forming the very substratum of all things (illusion or universe).

Advaita is the ultimate truth. Advaita,   the complete knowledge of the whole.

Even Rig Veda: ~ The Atman (Soul)  is the cause; Atman is the support of all that exists in this universe.

Thus, Sage Sankara’s wisdom is the ultimate truth declared 12 centuries back the Spiritual Truth, rational, truth, scientific truth, and the ultimate truth.

Remember 

Buddhist Sunyavada is incongruous because every thought has its opposite every word is tied to its coordinate for all thought and speech can only operate under such dualism. Hence, taking the most fundamental word, existence is implied opposite non-existence is also there, and vice versa. Therefore, the Sunya "non-entity" is meaningless without "entity". Both are there.

Buddhist Idealism speaks only of ideas.

What about the knower of these ideas?

Buddhist Nihilism does not ask "What is meant by Nihilism?

It is a thought. There must be a thinker of this thought.

Bhagavan Buddha kept silent, refusing to answer questions on the ultimate. Therefore, he was the wisest man in refusing to commit himself.

Zen is quite OK in mentioning non-duality: it is the nearest to Advaita, but it is still inferior because:~

(1) It fails to prove non-duality,

(2) It illogically gives ‘Koan’ exercises as a means of attaining that which is beyond attainment, because always here

(3) It talks about insight or intuition to see Reality when sight involves a second thing, duality.

When you say "Nothing is" what is the meaning of "is"? "Sunya" is something that exists: you cannot prove that consciousness does not exist.

Zen Buddhism gives high importance to meditation practice. The truth is that Zen advocates the necessity of meditation for those of its adherents who cannot grasp the absolute truth.

Zen Buddhism is also on this lower stage of Yoga because it depends on flashes of Intuition gained by meditation, not by reasoning.

Has the Void a meaning? If so then it is only your imagination.

Bhagavan Buddha gave up yoga after practicing it for six years. He saw it could not yield truth.

Bhagavan Buddha gave up his austerities of yoga as impossible and useless. (Page.70/71 "Buddhism in Translation” by Warren)

Bhagavan Buddha got enlightenment only after he gave up Yoga. Unless you exercise your Buddhi--reason--there is no chance of getting the truth, which is beyond form, time, and space. Buddhism is based on form alone, and it does not include time and space in its investigation.

Buddhism has not proved the truth of Nonduality. Bhagavan Buddha pointed out the unreality of the world. He told people they were foolish to cling to it. But he stopped there. He came nearest to Advaita in speech but not to Advaita fully.

Zen Buddhism Satori is not Advaitic wisdom because it comes as flashes, it does not depend on seeing the world and does not depend upon mental sharpness so much as intuition.

Zen Buddhists are only mystics ~ they do not offer proof. How is their main method different from that of Christian mystics, and Hindu mystics, all of whom do not seek to prove by reason, but by "I know," intuition? : ~ Santthosh Kumaar