On the emancipation of materia medica studies (honzōgaku) in early modern Japan

Since the pioneering work by the phytopathologist and natural historian Shirai Mitsutarō (1863–1932), the beginnings of genuine native studies on Japanese herbs have been linked to Kaibara Ekiken’s book “Japanese Materia Medica” (大和本草 Yamato honzō) published in 1709.[1] However, a closer look that includes Dutch source material from the second half of the 17th century reveals that there was more to this process of emancipation from Chinese herbology than the individual ingenuity of a neo-Confucian scholar. The harsh economic realities of the archipelago had a strong influence on all political decisions related to resources, imports, and exports from the very beginning of Japan’s Edo period (1603–1868). During the 1650s, the adoption of Western medicine led to the introduction of herbs and drugs that were not known hitherto and were imported from the Dutch East India Company. Insufficient and high-priced supply eventually stimulated an attempt initiated by the imperial councilor Inaba Masanori to start local production of certain medical materials and to investigate local plants, while requesting seeds and plants from the Dutch East India Company and the dispatch of herb specialists. Joint Dutch–Japanese botanical investigations and instruction about imported and local plants by European physicians and pharmacists provided a reference point (tertium comparationis) that enabled their Japanese counterparts to achieve a new view of such Chinese herbals as the “Principles and Species of Materia Medica” (本草綱目 Bĕncǎo gāngmù) while heightening their awareness of the distinctive properties of indigenous Japanese flora. About five decades before Shōgun Tokugawa Yoshimune (1684–1751) implemented his famous “herb policy”, almost identical attempts were made under Tokugawa Ietsuna (1641–1680). These activities faded out with the accession of his successor Tokugawa Tsunayoshi (1646–1709), but herb studies continued to be a common field of interest for Japan as well as for the Dutch East India Company throughout the Edo period.