Zhang Congzheng

Zhang Congzheng (Chinese: 張從正; pinyin: Zhāng Cóngzhèng; 1156–1228), courtesy name Zihe (Chinese: 子和; pinyin: Zihé), was a Chinese physician and writer active during the Jin dynasty. Based in the capital city of Daliang (大梁; present-day Kaifeng, Henan), Zhang was known for his aggressive and unorthodox approach to medicine, which was based on the belief that all illnesses were caused by "deviant" qi. He is regarded as one of the "Four Great Masters" of the Jin-Yuan period.