Duke Hwan of Khi, first in his dynasty, sat under his canopy reading his philosophy. And Phien the wheelwright was out in the yard making a wheel. Phien laid aside hammer and chisel, climbed the steps and said to duke Hwan, “May I ask you, Lord, what is this you are reading?” Said the duke: “The experts, the authorities.” Phien asked: “Alive or dead?” The duke said: “Dead, a long time.” “Then,” said the wheelwright, “you are only reading the dirt they left behind.” The duke replied, “What do you know about it? You are only a wheelwright. You had better give me a good explanation or else you must die.” The wheelwright said, “Let us look at the affair from my point of view. When I make wheels, if i go easy they fall apart, and if I am too rough they don’t fit. But if I am neither too easy nor too violent they come out right, and the work is what I want it to be. “You cannot put this in words, you just have to know how it is. I cannot even tell my own son exactly how it is done, and my own son cannot learn it from me. Se here I am, seventy years old, still making wheels! The men of old took all they really knew with them to the grave. And so, Lord, what you are reading there is only the dirt they left behind them.”