Bo Le was a renowned expert in judging horses in ancient China, and his book On the Physiognomy of Horses was a classic text on the subject.
His son, eager to master his father's skill, studied the book diligently. He carried it with him everywhere. Whenever he saw a horse, he would take out the book and meticulously compare the animal to the drawings inside.
One day, he finally found a horse that closely matched one of the book's illustrations. He led it home triumphantly. However, it turned out to be an inferior horse with a fiery temperament, not the good steed capable of galloping a thousand li in a day that he had hoped for.
Bo Le said to his son, "If you look for a steed solely with the aid of drawings, how can you ever find a truly fine one?"