When one says "Nothing is" what is the meaning of "is"? "Nothingness” is something which exists: one cannot prove that consciousness does not exist.

The dream entity and the dream world are created out of consciousness and they are not different from it; similarly the waking world entity and waking world are also created out of consciousness. The dream becomes unreal when waking takes place. The waking becomes unreal when wisdom dawns. The wisdom dawns when waking entity realizes the fact that, the self is neither the waking entity nor the self is dream entity but the self is the formless soul or consciousness, which witnesses the coming and going of the three states without the physical apparatus. Deeper self-search reveals the fact that, the three states are one in essence because the substance and witness of the three states are one in essence.  And that essence is consciousness. Thus there is no second thing exists other than consciousness. When one knows that everything is consciousness than there is no need for yogic control of mind. Control presupposes second, a duality. Hence yoga is in the sphere of duality and is unnecessary to one who knows non-duality.

BRIHAD. UPANISAD( page 32):- "Yoga does not yield truth or liberation."

BRIHAD Upanishad(Page 133 1st para) :-  Even yoga cannot give perfect concentration and that the only way to gain it is philosophical realization.

Mandukya Upanishad declares:-  Yoga cannot give you truth. yoga can no more succeed than the ocean can be emptied with a blade of grass.

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

Thus Buddha got enlightenment only after he gave up Yoga. Unless one exercises his reason--there is no chance of getting truth.

 Buddhism has not proved the truth of Non-duality.  There is no doubt Buddha pointed out unreality of 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.

 When one says "Nothing is" what is the meaning of "is"? "Nothingness” is something which exists: one cannot prove that consciousness does not exist.

Has the Void a meaning? If so then it is only your imagination.  Buddha gave up yoga after practicing it for six years. He saw it could not yield truth. 

Non dual wisdom requires investigate in to the mind, analyzing the mind, which is in the form of universe and universe appears as waking or dream.  One has to the fact that, the mind rises and subsides from formless source, which is soul or consciousness. The consciousness is the innermost self. Therefore, one has to learn to judge the truth from the standpoint of the source from where the mind rises and subsides, not from the standpoint of the waking entity, which is the false self within the false experience.

As one gets convinced, certain, of the truth that the world is nothing but consciousness, and there is no second thing, then he gets conviction that, all the three states to be consciousness in the midst of duality. Realizing the non-dualistic or Advaitic truth in the midst of duality is wisdom.--FORMLESS PATH