"When a fish swims, he swims on and on, and there is no end to the water. When a bird flies, he flies on and on, and there is no end to the sky. From the most ancient times, there was never a fish who swam out of the water or a bird that flew out of the sky. Yet when the fish needs just a little water, he uses just a little, when he needs a lot, he uses lots. Thus the tips of their heads are always at the outer edge (of their space). Yet if there were a bird who first wanted to examine the extent of the sky, or a fish who first wanted to examine the extent of the water — and then tried to fly or to swim, they will never find their own ways in the sky or the water."