"Thorns, although embedded for a long time, still can be pulled out. Stains, although filthy for a long time, still can be washed away. Knots, although tied for a long time, still can be untied. Obstructions, although blocked for a long time can be opened up...The skillful acupuncturist can take hold of the dis^ease in the same way [s]he pulls out thorns, washes out stains, unties knots, or breaches obstruction."
- Ling Shu, or The Spiritual Pivot, written 204 B.C.