Śvetaketu went away to study at twelve and came home at twenty-four, and he came home insufferable.
Twelve years. He had learned everything there was, and he was fairly sure everyone could tell.
His father Uddālaka let him get through the door, and then asked one question. Not what he had learned. Whether he had asked for the teaching by which what you have not heard becomes heard, and what you have not thought becomes thought.
Śvetaketu said he had not. He said he did not think his teachers knew that one, or they would have taught it. Then he asked to be taught it.
His father gave him a lump of salt and a bowl of water and said: put that in there, and come to me in the morning.
That was the lesson for that night. Twelve years of study, and a bowl of water on a shelf.
In the morning his father said: bring me back the salt you put in last night.
He put his hand in. There was nothing to bring. He felt around the bottom of the bowl like a man looking for keys.
Sip from this end, his father said. Salt. From the middle. Salt. From that end. Salt.
Now put it down and come here. It is still there — you simply cannot pick it up.
And that is the whole demonstration. The salt has not gone anywhere. It is in every mouthful of that water, you cannot see one grain of it, and you could not get it out again if you tried all day.
You cannot see it here, his father said, and it is here.
Then he said the sentence people have been arguing about ever since: that the finest thing, the thing you cannot point at, is what all of this is made of — and that, Śvetaketu, is what you are.
He had come home able to answer anything. His father asked him for a lump of salt, and he could not.