The Ailment
The following is a well-known tale from the Liezi attributed to Taoist Lie Yukou. It appears in various translations such as A.C. Graham's The Book of Lieh-tzu (p82 pdf) and Eva Wong's Lieh-tzu: A Taoist Guide to Practical Living. The following is quoted from the Thomas Cleary translation (details provided at the end):
Lung Shu said to the physician Wen Chi, "Your art is subtle. I have an ailment; can you cure it?