Story about a Fish and a Turtle: Is Nibbāna Nothingness?

"Nibbāna is bliss supreme."
---Dhammapada

Once upon a time there was a fish. And just because it was a fish, it had lived all its life in the water and knew nothing whatever about anything else but water. And one day as it swam about in the lake where all its days had been spent, it happened to meet a turtle of its acquaintance who had just come back from a little excursion on the land.

"Good day, Mr. Turtle!" said the fish. "I have not seen you for a long time. Where have you been?"

"Oh", said the turtle, "I have just been for a trip on dry land."

"On dry land!" exclaimed the fish. "What do you mean by on dry land? There is no dry land. I had never seen such a thing. Dry land is nothing."

"Well," said the turtle good-naturedly. "If you want to think so, of course you may; there is no one who can hinder you. But that's where I've been, all the same."

"Oh, come," said the fish. "Try to talk sense. Just tell me now what is this land of yours like? Is it all wet?"

"No, it is not wet," said the turtle.

"Is it nice and fresh and cool?" asked the fish.

"No, it is not nice and fresh and cool," the turtle replied.

"Is it clear so that light can come through it?"

"No, it is not clear. Light cannot come through it."

"Is it soft and yielding, so that I can move my fins about in it and push my nose through it?"

"No, it is not soft and yielding. You could not swim in it."

"Does it move or flow in streams?"

"No, it neither moves nor flows in streams."

"Does it ever rise up into waves then, with white foams in them?" asked the fish, impatient at this string of Noes.

"No!" replied the turtle, truthfully. "It never rises up into waves that I have seen."

"There now," exclaimed the fish triumphantly. "Didn't I tell you that this land of yours was just nothing? I have just asked, and you have answered me that it is neither wet nor cool, not clear nor soft and that it does not flow in streams nor rise up into waves. And if it isn't a single one of these things what else is it but nothing? Don't tell me."

"Well, well", said the turtle, "If you are determined to think that dry land is nothing, I suppose you must just go on thinking so. But any one who knows what is water and what is land would say you were just a silly fish, for you think that anything you have never known is nothing just because you have never known it."

And with that the turtle turned away and, leaving the fish behind in its little pond of water, set out on another excursion over the dry land that was nothing.

It is evident from this significant story that neither can the turtle, who is acquainted with both land and sea, explain to the fish the real nature of land, nor can the fish grasp what is land since it is acquainted only with water. In the same way Arahants who are acquainted with both the mundane and the supramundane cannot explain to a worldling what exactly the supramundane is in mundane terms, nor can a worldling understand the supramundane merely by mundane knowledge.

Nibbāna is the summum bonum of Buddhism.

Source: "The Buddha and His Teachings" by Venerable Nārada Mahāthera