There was a well not far from the oceanside in which a frog had lived his whole life. Being foolish and proud, he considered the well to be his own property, and thought there was no better place for a frog to live. Indeed, the frog thought the well to be the whole world.
One day another frog happened to stumble into that well. The well-frog was surprised at this sudden visit of a strange frog from outer space. A discussion then ensued.
Well-frog: “Where do you come from?”
Visiting-frog: “From the oceanside.”
W-f: “What is this, ‘ocean’?”
V-f: “It is a vast body of water.”
W-f: “Oh. Would you say it is up to half the size of my well?”
V-f: “Your well does not compare in any way to the size of the ocean. The ocean is unlimited.”
The well-frog then gave a jump from one end of his well to the other. “See?” he said to the newcomer-frog. “I’ve just proven that nothing greater than this can exist.”
The visiting frog’s eyes bulged in astonishment. “You really believe that? I think you’ve been in this hole in the ground far too long. If you get out of here and see the ocean, then you’ll know how insignificant your little well is in comparison.”
The well-frog was irritated. “Why be so fanatical? I don’t doubt that the ocean may be as large as my well. I’m not so narrow-minded as to declare my well to be the biggest body of water in all existence. Your boasting about the ocean is just unscientific. Look, I’ve just performed an experiment that demonstrates that nothing can be larger than this well. Now let’s talk sense. There’s water here, and there’s water in your ocean. So certainly they must be of equal size. This is my strong conclusion. Give up this fanaticism and be reasonable.”
There are scientists, philosophers and intellectuals everywhere who attempt to establish a standard of reality based upon their own limited powers of observation. All of them may be compared to Dr. Frog making his thesis on the maximum possible size of a body of water.