Yī Yǐn 伊尹 was the legendary chief minister of Tāng 湯, founder of the Shāng dynasty (trad. 17th c. BCE). The medical tradition attributes to him the lost Tāngyè jīngfǎ 湯液經法 — the decoction-pharmacology that, in the revisionist reading of 馮世綸 and others, is supposed to be preserved in fragmentary form in the Fǔxíng jué zàngfǔ yòngyào fǎyào (KR3eh001). The attribution is essentially mythological.