This term refers to natural, unadorned beauty. “Pure” means untainted, unadulterated or containing no impurity. Su (素) originally means “undyed raw silk.” Later it came to mean“ the quality of being white, authentic, unspoiled or undecorated.” Daoist thought, represented by Laozi and Zhuangzi (369?-286 BC), held that Dao is the ultimate origin of beauty in everything. Dao is natural, unassertive, simple and unadorned. Thus Daoists consider being natural, unadorned and pure as the highest form of beauty. Ancient thinkers believe that “pure and unadorned” is an authentic state of being, which retains its holistic true status free from external objects. Even if it mixes with the latter, it keeps itself natural and its core essence unimpaired. This idea extensively influenced the writing style and aesthetic pursuit of ancient Chinese literature and art. Plain and quiet poetry and plain and natural painting were upheld in ancient China, which reflect the aesthetic pursuit of the pure and unadorned.

Within spiritual being lies the value of pure simplicity. If you retain your spirit without fail, you became one with it. In achieving that oneness, you establish contact with the way of heaven... “Simplicity” means “not mixing”; “pure” means “an unimpaired spirit.” Only if you embrace pure simplicity can you be called a true man. (Zhuangzi)