Quantitative Orthographic Analysis of the Ogura Shikishi

Abstract

The Ogura shikishi 小倉色紙 are a group of squarish cards inscribed with classical Japanese poems in the distinctive calligraphy associated with the later years of the illustrious poet Fujiwara no Teika 藤原定家 (1162–1241). About fifty of these shikishi have been recorded and some are extant in prestigious collections. All of the inscribed poems appear in the famous anthology Hyakunin isshu 百人一首 (One Hundred Poems by One Hundred Poets), whose compilation has been traditionally attributed to Teika. The Ogura shikishi were said to have been brushed by Teika himself, an assertion which is generally doubted, but there exists no clear evidence on whether it is true.

We approach the question of authenticity by analyzing patterns in the use of jibo 字母, the Chinese characters that are highly cursivized in order to create hiragana, a phonetic syllabary. In premodern Japanese, the same sound could be represented by multiple hiragana, each based on a different jibo. As the choice of jibo seems largely a matter of personal preference, it holds demonstrated potential for authenticating premodern Japanese handwriting that includes hiragana.

After comparing jibo data derived from a group of manuscripts attributed to the hand of Teika with high confidence and comparing it with the data of jibo used in the Ogura shikishi, we conclude that the probability that Teika brushed any of the Ogura shikishi ranges from low to extremely low. That is, all of the Ogura shikishi were probably inscribed by persons other than Teika. Finally, we consider the inscriptions that appear on the versos of two of the Ogura shikishi and, by the same methods used to evaluate the rectos, conclude that the verso inscriptions were indeed probably brushed by Teika and reused to make the Ogura shikishi, perhaps in an attempt to endow them with a veneer of credibility.