Shuyi 書議

Shuyi 書議, also called Yishu 議書 or Lunshu 論書, is a text on calligraphy written during the early Tang period 唐 (618-907) by Zhang Huaiguan 張懷瓘 (mid-8th cent.) from Hailing 海陵 (today’s Taixian 泰縣, Jiangsu). Zhang is more famous for his book Shuduan 書斷.

The Shuyi was finished in 758. It primarily focuses on evaluating and ranking the four writing styles: The standard script (zhenshu 真書), the "running script" (xingshu 行書), the clerical cursive script (zhangcao 章草), and the super-cursive "grass script" (caoshu 草書), while also discussing the techniques of each style. The author comments on the qualities of the four script styles separately, noting the outstanding works of a few individuals over hundreds of years. Zhang rates the quality of artists by adhering to the principle that "those with spirit and strength in their work are ranked higher, while those with beauty and utility are ranked lower". He evaluates the artistry of the best calligraphers from the Han 漢 (206 BCE-220 CE) to the Jin 晉 (265-420) period by discerning between the four writing styles and three ranks of quality. With a flexible method of evaluation, he first lists those whose works are described as "their fame flies a thousand miles, their glory shines for a hundred generations" (sheng fei wan li, rong yao bai dai 聲飛萬里，榮耀百代), and who "have mastered the art over hundreds and thousands of years" (qian bai nian jian de qi miao zhe 千百年間得其妙者).

This approach of critique aligns with what Zhang describes as "establishing criteria as a measure of judgment; impartial towards all things, neither favouring nor diminishing, convinced solely by reason (wei yi li fu 惟以理伏), and capable of confronting the truth face-to-face." Zhang also admits that not every master was fully proficient in all fields, and that appreciation was not necessarily an objective matter, but depended on the era. However, true calligraphy critique must possess the wisdom to understand others and ensure that their views can withstand objective scrutiny.

In the discussion on script styles, the essay points out that in the regular script (zhenshu), when a character is completed, its meaning is also concluded (zi zhong, yi yi zhong 字終意亦終), whereas in the grass script, even when the writing ends, the momentum remains unfinished (xing jin, shi wei jin 行盡勢未盡). There were also masters who combined the two writing styles.

The essay is quoted in the books Fashu yaolu 法書要錄 and Shuyuan jinghua 書苑菁華 and is included in the series Lidai shufa lunwen xuan 歷代書法論文選.