Berkeley could not say anything.
The friendship ended because this is no way to argue. But Berkeley was unaware of the Indian mystics. Had he known anything of Indian mystics he would have answered Dr. Johnson perfectly well. Berkeley was bringing a new idea to Western philosophy. In India it has existed for centuries. It is said about the great Buddhist monk, Nagarjuna, that he was caught hold of by the king of the country because he was saying that nothing exists, nothing at all. Existence is a pure dream.
He was far ahead of Berkeley and anybody else because he was saying the world is a dream, and because the dream is false how can the dreamer be true? The world is false, it is a dream, and because the dream is false the dreamer is false. So nothing exists: neither the dreamer nor the dream. Shankaracharya at least accepts that the dreamer is true, and Berkeley also accepts that the subjective is true, the objective is false. But Nagarjuna seems to be far more clear. If the objective is false, how can the subjective be true? If the seen is false, what is the proof of the seer? If the known is false, then how can the knower exist? – on what grounds?
He was caught hold of by the king. The king was a very pragmatic man. He must have been like Dr. Johnson; maybe Dr. Johnson was just another incarnation of the same king. He caught hold of Nagarjuna, he listened to his ideas. It was difficult to argue with him, almost impossible. How can you prove that life is true?
For example, we are sitting here. I may be just dreaming you, or you may be dreaming me, or we both may be dreaming simultaneously. But what proof is there that you are really there and I am really here, that I am talking to you and you are listening to me? It may be just mind stuff, nothing else. And many times in your dreams you have seen me. Of course, I don’t dream; so I don’t see you in my dreams. I am so fed up seeing you the whole day that it is natural I don’t see you in my dreams. And orange is such a dangerous color.
The king could not argue with Nagarjuna, but he had a mad elephant. So he asked the mad elephant to be brought before the palace. The person who was ordered to bring the mad elephant asked why.
The king said, “We have to give proof to Nagarjuna. We have to see what happens when the mad elephant chases him, catches hold of him and throws him a hundred feet away. Then we will see whether it is a thought or a reality!”