Song Yingxing wrote the preface to Tiangong kaiwu, his book on crafts and production, in 1637. He explains the order of its chapters: “The chapters run from front to back in the sense of valuing the five grains and despising gold and jade.” The first chapter is on grain.
Among all things, he notes, “half are useless to human life and half are useful.” He ends the preface: “This book has nothing at all to do with seeking office.”