Yamawaki Toyo (山脇東洋)
Toyo YAMAWAKI (February 1, 1706 - September 25, 1762) was a medical scientist in the Edo period. He was one of the pioneers in experimental medicine. Toyo was the name he started to use later in his life; he called himself Izan before that. His real first name was Hisanori, and his nicknames were Genhi and Shihi. His son was Tomon YAMAWAKI, and one of his students was Dokushoan NAGATOMI.
Brief Personal History
He was born in Kameyama in Tanba Province. He was born to a doctor family, the Shimizu family, and in 1726, he was adopted into the hogen of the Yamawaki family, whom his father was studying under. In 1729, he took over the family and became the hogen. He learned from Konzan GOTO in the school of Kohoha medicine which put more importance on practice than theories, and in 1746, he reprinted a medical book originally written in the Tang dynasty called "Gedaihiyoho."
He questioned the human anatomical chart created based on the Inyo-gogyo-setsu (the China-origin doctrine that everything in the universe is made of five basic elements, and has two opposite aspects) when he dissected an otter; therefore, he dissected and observed the body of an executed criminal in March 1754 with permission of the Kyoto shoshidai (governor general). In 1759, he published his observations as an illustrated anatomical book called "Zoshi." In the book, he pointed out fallacious understandings of bodily functions such as Gozo-roppu-setsu developed by Chinese medicine doctors.
The book received much criticism because doctors had strong hesitation to dissect a human body in koiho (school of ancient medicine) led by Todo YOSHIMASU, but the first human body dissection in Japan proved the accuracy of the Dutch medical literature, giving a strong impact on the medicine community. Inspired by Toyo, in the city of Edo, Genpaku SUGITA, Ryotaku MAENO and others started to translate a Dutch medical book with higher accuracy. Thus, Toyo greatly contributed to the modernization of Japanese medicine.