唐、宋詩歌格律對「下三字」規範的進程

本文是漢詩格律發展系列研究的重要環節，在資料上，以漢字文化圈作為整體的視域，向域外尋求與中土平行的共時性詩學資料；在方法上，運用數位工具落實理論文獻與格律分析的交互證成；在觀念上，強調文獻的時代性與理念銜接的邏輯性，期以變動推進的史觀重構格律發展史。本文經由研析一系列日本詩格，包括《文鏡秘府論》、《作文大躰》、《王沢不渇鈔》的格律論述，再與中土的詩選、詩格著作，如《唐人選唐詩》、《詩人玉屑》、《瀛奎律髓》進行相互論證。藉以說明自唐至宋，律詩從「拈二」發展至「二四黏對」確立了主導節律之後，對於五言詩第三字的規範，如何從「調聲三術」的「護腰」進展到「避下三連」再到「三五異聲」，並且，除了用於五言詩也運用於七言詩的相對位置。綜言之，「避下三連」的完成，律詩的每一個字皆被規範化，標示著唐詩格律已經走完建構階段的最後一里路；至於宋人後續再發展出「三五異聲」，則是規範更趨精微的進階考量。

關鍵字

格律；護腰；避下三連；《王沢不渇鈔》；《詩人玉屑》；《瀛奎律髓》

並列摘要

This article examines the development of metrical patterns in Chinese poetry. With respect to source material, I have employed Sinosphere as an integral domain of vision, while also seeking out-of-domain poetic texts parallel to those in China. With regards to methodology, I have used digital tools to carry out the interactive corroboration between theoretical literature and metric analysis. And conceptually, I have emphasized the logic informing the literary era and connections between ideas, adopting a historical view regarding the change and development of metrical patterns. In the article, I compare a series of Japanese composition rules for poetry, including those found in the Bunkyou hifulon 文鏡秘府論, Sakumon daitai 作文大躰, Outaku fukatsushou 王沢不渇鈔, against texts that contain writing rules for Chinese poetry, such as the Tang ren xuan tangshi 唐人選唐詩, the Shiren yuxie 詩人玉屑, and the Yingkui lüsui 瀛奎律髓. On the basis of this analysis, I explain how metrical poems developed from ＂the second-character rule＂拈二 to ＂the second-and-fourth- character rule＂二四黏對following the establishment of dominant rhyme patterns in the Tang and Song dynasties. The relevant issues concerned: how to regulate the third character in five-character poems; how its regulation proceeded from ＂protecting the waist＂護腰 to ＂avoiding the same tone in the last three characters＂避下三連, and subsequently to ＂different tones in the third and fifth character＂三五異聲. The regulation applied not only to five-character poems, but also to seven-character poems. In sum, after establishing the norm of ＂avoiding the same tone in the last three characters,＂ each character of the poem became standardized, indicating that Tang poetry had already completed the last stage in the construction of metrical patterns. As for the development of ＂different tones in the third and fifth character＂ by later Song poets, it should be seen as a more advanced consideration of the norm.