The Trouble with The Watcher

Osho,
How can we be certain that the watcher is not part of the mind?

“It is a relevant question but only intellectually. It is not out of meditation because the man is bringing into his question three things of which he is not aware: the mind, the watcher — and who is this third who is thinking whether the mind and the watcher are one thing? There is a third entity which is raising the…