Yoshida Chosyuku (吉田長淑)

Chosyuku YOSHIDA (or Chokei, Nagayoshi) (male, 1779-September 2, 1824) was Dutch scholar and Ranpoi (a person who studied Western medicine by means of the Dutch language). His name was Seitoku, his azana (nickname) was Jikishin and his go (second name or alias) was 齣谷, 蘭馨, Chosyuku. His disciples were Choei TAKANO, Kazan WATANABE, Sanei KOSEKI, Chosyun ADACHI, Shutoku KAWAMOTO, Shunzan SUZUKI and Choan MINATO.

Biography
Career
Chosyuku was born in Tokyo in 1779. His father was Hyoemon Baba who was the vassal of the shogun. Later, he was adopted to the Yoshida family which was his maternal relative and succeeded its family. Because he was not satisfied only by becoming the disciple of Chogen TOKI, Chinese medicine doctor to study medical science, he learned Western studies by Hoshu KATSURAGAWA (the fourth), Ranpoi in Edo-Igakukan (medical school) of the Edo bakufu (Japanese feudal government headed by a shogun) and in Fuundo, the private school of Genshin UDAGAWA who was the head of the big four of Shiran-do.

When Harunaga MAEDA, the eleventh lord of the Kaga domain fell ill in edohantei (residence maintained by a daimyo in Edo) in 1808, Genshin UDAGAWA, Chosyuku's teacher succeeded in curing it. Genshin firmly refused the invitation from the Kaga domain due to this result, and then Hotei FUJII, the high-caliber disciple of Fuundo and Chosyuku were recommended instead of Genshin. Since then, Chosyuku had been under the patronage of the Kaga domain.

He taught younger people in his private school, Rankeido while he contributed to the development of internal medicine, mainly translating the medical books of the Western internal medicine. When Harunaga MAEDA, who was the lord of the Kaga domain and Chosyuku was under the patronage of, fell ill in July 1824, Chosyuku running to Harunaga to repay a big obligation also fell ill on the way due to the strain of his trip and unfortunately Harunaga had been dead at Chosyuku's arrival in Kaga. In disappointment, he died the next year, in September 2, 1824. His age at death was 47.

Achievement
Because Japan limited its diplomacy with the West to the Netherlands due to the national isolation, Western studies were called Rangaku, the studies of the Netherlands. However, oriental medicine was considered as internal medicine and Western medicine was considered as surgery in that period when Rangaku was abused to call Bangaku (barbaric studies). This was another name meaning the outside of the medical science, different from the current distinction of internal medicine and surgery.

Under such environment, Chosyuku translated many academic books related to the internal medicine of Western medicine and opened the hospital as Western physician for the first time in Japan. Though he was much criticized by the oriental medicine specialists and closed his hospital, many people including the Kaga domain supported Chosyuku's reliable skill and personality, which contributed greatly to the development of internal medicine in Japan. Shoshikai (salon, a think tank) which was the group of Western studies and established by Chosyuku's disciples after his death was oppressed by the Edo bakufu, but it played a great role as one of the driving forces to move subsequent Japan.

Books
Naikagekan
Ranyakukyogen
Taishinetsubyoron

[Original Japanese]