著者

法貴 遊

出版者

史学研究会 (京都大学大学院文学研究科内)

雑誌

史林 = The Journal of history (ISSN:03869369)

巻号頁・発行日

vol.103, no.1, pp.41-71, 2020-01

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アラビア医学史研究において医療実践は、史料上の制約もあり、主な研究対象とはならなかった。この状況で、十一世紀から十三世紀半ばにかけて書かれたカイロ・ゲニザの医学関連文書が、医療実践を記録している史料として注目されている。本稿では、カイロ・ゲニザの二通の書簡における実践の記され方について考察する。一般的なアラビア語医学文献は普遍的な知識を記述対象とするため、個々の実践は記述されない。中世アラビア医学では、個体は普遍的な枠組みを通して認識されるため、言論では分析できない事柄を医療の現場で非言語的に把握することが求められた。カイロ・ゲニザ文書に記された実践例を読み解くことで、当時の医者が言論では把握できない事柄(患者の自然本性の動きや四性質の微妙なバランス)に注視し、これとの関係で治療方針を定めていたことが推測できる。The practical dimensions ofmedieval Arabic medicine have not been sufficiently studied due to the dearth of historical documents. Concrete cases were excluded from most medieval Arabic medical writings because subjects ofmedical books were limited to universal scientific knowledge ('ilm). In this situation, the Cairo Genizah fragments, which were written during the 11th‒13th centuries, are drawing attention because they record unique information about practical aspects of medicine. This article takes up epistemological problems concerning medical practice, and inquires which aspects ofmedical practice were, and which were not, put into words by examining medieval Arabic medical books and two letters ofthe Cairo Genizah (T-S 10J16. 16 and T-S NS 327. 93). Both letters concern ophthalmology, and describe the whole process from diagnosis to treatment. These documents reveal that some elements ofpractice were not caught in the net ofscientif ic language; nevertheless, ophthalmologists conducted treatment by observing these nonverbal elements. The first section encapsulates medieval physicians' arguments concerning the epistemological status ofmedical practice. al-Majūsī (d. 990) divided medicine into theory ('ilm) and practice ('amal), and defined practice as putting ideas into execution. However, the practical sections in his book do not contain concrete information on actual practice, but knowledge about medicinal substances and treatment plans for specific diseases. Ibn Sīnā (d. 1037) found al-Majūsī's inconsistency between the definition and real content a flaw. He accordingly defined theory as theoretical knowledge and practice as practical knowledge. Hence, Ibn Sīnā entitled both theory and practice to scientific knowledge, whereas information on actual practice ('amal bi-l-f'il) was not regarded as scientific knowledge and thus excluded from medical books. Medieval physicians acknowledged that some elements of actual practice passed through the mesh oflanguage. Ibn Rushd (d. 1198) argued that objects defined by language are limited to things related to forms (s. ūra), whereas things related to matter (hayūlā) are only roughly described because the latter is infinitely changeable in various relationships with other matter. However, medieval ophthalmologists, who appeared in the genizah letters, conducted consistent treatments based on the observation ofthese non-verbalized things related to matter. The second section discusses diagnoses and treatments written in the two letters. We firstly focus on the diagnoses. In T-S 10J16.16, an ophthalmologist called Abū Zikrī identifies a patient's eye diseases as conjunctivitis, an eruption ofthe eyelid, and a corneal ulcer, and describes their characteristics in detail. Meanwhile, the writer ofT-S NS 327. 93 enumerates several symptoms: excavation, severe pain, floaters, leucoma. Considering their depictions, their diagnoses are found to have properly reflected medieval Arabic diagnostics. These two examples indicate that the diagnostic theory written in medical books was perfectly implemented. Next, the treatments are examined. The condition ofthe eye described in T-S 10J16.16 was regarded as a composite ofthe three ailments. Abū 'Alī, Abū Zikrī's correspondent, instructed him on several treatments, each of which is effective against a specific disease and does not aggravate the others. Medieval ophthalmologists recognized a need for treatments suitable for complicated cases; however, ophthalmology books did not always present concrete instructions. The treatments should have been adjusted to the subtle balance ofthe temperament ofa complicated condition; nevertheless, ophthalmologists did not have technical language to estimate the ratio ofthe temperament. This letter suggests that the actual treatment was affected by the observation ofthe nonverbalized elements. Meanwhile, the writer of T-S NS 327.93 mentions four different treatments that were done at some intervals oftime . Medieval ophthalmologists supposed that every disease progresses along four stages: incipient (ibtidāʾ), increasing (tazayyud), terminating (intihāʾ), and convalescent (inh. it.āt.). Therefore, the four treatments written in the letter are presumed to have been allotted to the four stages. A characteristic of this letter is that the writer mentioned the number ofdays each stage lasted. However, the span oftime is not mentioned in ordinary medical books. It is because the actual treatment process was affected by the relationship between patient's nature (t. abī'a) and medical intervention. According to Maimonides (d. 1204), nature is an independent efficient cause external to the medical system, and not totally defined by scientific language. This letter indicates that ophthalmologists had to determine treatment plans by reconciling nonverbal elements with the medical system. These two examples ofmedical practice basically follow medieval Arabic medical theory. However, the theory is a large-meshed net. It is comprehensive; nevertheless, on the practical level, many elements (subtle nuances ofthe temperament and patient's nature) spilled out ofthis net. By comparison ofthe Cairo Genizah letters with Arabic medical books, we can infer that ophthalmologists grasped these elements and decided treatment plans.