Nanbei shupai lun 南北書派論 and Beibei nantie lun 北碑南帖論

Nanbei shupai lun 南北書派論 "On the southern and the northern schools of calligraphy" is a book on calligraphy written during the late Qing period 清 (1644-1911) by the eminent scholar Ruan Yuan 阮元 (1764-1809), who is most famous for his edition of the complex commentaries on the Confucian Classics, Shisanjing zhushu 十三經注疏, and the series Huang-Qing jingjie 皇清經解.

The essay had a deep impact on the study of the history of calligraphy by presenting views on the changes in calligraphy through history, the establishment of the Northern and Southern schools of calligraphy, and the formation of different calligraphic styles and shapes. Ruan Yuan continued and deepened the traditional classification of north-style and south-style calligraphies that was geared to certain lineages of scholarly transmission of the art of writing and calligraphy. While Zhong Yao 鍾繇 (151-230) and Wei Huan 衛瓘 (220-291) were still teaching unified models and styles, the division into north and south began with Wang Xizhi 王羲之 (303-361), Wang Xianzhi 王獻之 (344-386), Wang Zengqian 王僧虔 (426-485), Zhiyong 智永 (6th cent.) and Yu Shinan 虞世南 (558-638), who represented the southern school of calligraphy, and Suo Jing 索靖 (239-303), Cui Yue 崔悦, Lu Chen 廬諶 (285-351), Gao Zun 高遵 (late 5th cent.), Shen Fu 沈復, Yao Yuanbiao 姚元標 (6th cent.), Zhao Wenshen 趙文深 (6th cent.), Ding Daohu 丁道護 (c. 600), Ouyang Xun 歐陽詢 (557-641) and Chu Suiliang 褚遂良 (596-658) as the representatives of the northern style. The division between northern and southern was ended by Emperor Taizong 唐太宗 (r. 626-649) of the Tang dynasty 唐 (618-907), who put the two Wangs on the throne of calligraphers, and so ended the debate.

In terms of style, the Southern School or Jiangzuo 江左 style, expressed sparsity and elegance in sometimes virtually unrecognizable brushstrokes. It showed its greatest strength in official documents (qidu 啟牘). The style of the Northern School was characterized by crude and clumsy characters and was very strong in stone slab inscriptions and large name boards for buildings (beibang 碑榜 or 碑牓).

Ruan's essay Beibei nantie lun 北碑南帖論 "On the northern stone inscriptions and the southern model boards" expounds the development and history of stone inscriptions—prevalent in northern China—and model calligraphy boards as used in southern China. With regard to both types of master calligraphies, two scholarly disciplines had emerged, namely "stone inscription studies" (beixue 碑學), and "model board studies" (tiexue 帖學). Ruan Yuan thus perpetuated the tenet of strict division between north and south. In fact, however, there was a vivid exchange between the two modes of transmitting master calligraphies, and the difference between northern and southern styles was far from evident.

Both texts are included in Ruan's collected works Yanjingshi ji 揅經室集 and in the series Lidai shufa lunwen xuan 歷代書法論文選.