No-Self
When thoughts cease, who are you? An utter emptiness, nothingness, no-thingness.
It is because of this that Buddha has used a strange word; nobody has ever done such a thing before, or since. The mystics have always used the word 'self' for the interiormost core of your being -- Buddha uses the word 'no-self'. And I perfectly agree with him; he is far more accurate, closer to truth. To use the word 'self' -- even if you use the word 'Self' with a capital 'S', does not make much difference. It continues to give you the sense of the ego, and with a capital 'S' it may give you an even bigger ego.
Buddha does not use the words atma, 'self', atta. He uses just the opposite word: 'no-self', anatma, anatta. He says when mind ceases, there is no self left -- you have become universal, you have overflowed the boundaries of the ego, you are a pure space, uncontaminated by anything. You are just a mirror reflecting nothing.
-Osho, “The Dhammapada - The Way of the Buddha, Vol 1, #1”