A well-learned Professor of natural history was on sabbatical, traveling the Far East, searching for knowledge. He had heard stories of a wizened old monk who lived a simple life in the mountains, so the Professor traveled up the steep path to the monk. At the end of the path was a small, well-kept dwelling, with the monk sitting outside, tending to his garden. The monk graciously invited the good Professor inside for tea.

Upon entering, the knowledgeable Professor began commenting upon each and every single object in the the abode. "That's nice, but this is a better way..." and "I prefer the English way of doing this..." and "Oh, so that's how you Chinese do it, eh? Tsk, tsk. Back in England, we..." spoke the Professor. The monk quietly smiled and boiled the water for the tea.

The monk motioned the Professor over to the table once the tea was prepared. The Professor kneeled at the table, observing on the English tradition of chairs, which was obviously better and more comfortable. The monk quietly smiled as he poured himself a cup of tea.

Then the monk began to fill the Professor's cup of tea. And the Professor said, "That's enough. Thank you." but the monk kept pouring. And the Professor said "That's too much! I appreciate your generosity." and the monk kept pouring. And the Professor exclaimed "Good sir! The cup is overflowing, can't you see that? It's full! You can't add any more to it!" and the monk kept pouring. The Professor, whose pants were now wet with spilled tea, began to feel like he was dealing with a fool. He stood up and was about to leave when he heard the monk speak...

"The cup was full, and there was room for no more. So you must empty your cup if you wish it to be filled."