Yoshio Kōsaku

As a member of one of the five samurai families supported by the Tokugawa shogunate as hereditary official Dutch translators, Kōsaku vetted imported documents (Christian materials were prohibited in Edo period Japan) and helped to keep the shogunate informed of global political matters.

[2]" He maintained a Dutch style home and Dutch-style medical school, which at times enrolled up to six hundred students.

Kōsaku wrote thirty-nine works, mostly on topics related to rangaku, and mentored a number of students, including Sugita Genpaku.

[2] In his writing, Kōsaku was critical at times of Japanese society, particularly in the attitudes and manners of the citizens of Edo, the shogunal capital.

This document, included as part of a preface to the first integral translation of a European book to be published, was but one of many written by rangaku scholars at this time implying a need to rethink the Japanese attitude of Europeans as barbarians and of China as the only model for enlightened civilization.