The scale of traditional herbal medicine knowledge in East Asia is enormous. One example that shows us this is the work of Seo Yu-gu (1764–1845), a Confucian scholar of the Joseon dynasty in the nineteenth century. He wrote Imwon-Kyungjeji, an encyclopedia compiling almost all the contemporary East Asian knowledge. This book was nicknamed Britannica of Joseon because it covered the overall knowledge fields of human life—agriculture, forestry, animal husbandry, cooking, brewing, construction, civil engineering, crafts, calligraphy, music, commerce, and medicine. Surprisingly, about half of the entire work is about medicinal knowledge, occupying 1.2 million characters of the total 2.5 million characters. This means half of the traditional knowledge in East Asia is related to the treatment of diseases and maintaining human health.