Abstract
Objectives : This paper aims to investigate the role of the sweet flavor within the contexts of 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' and the meaning of the two concepts. Methods : Related contents in databases including the Siqu Quanshu were searched with 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin', whose understanding and application were examined. Results & Conclusions : The theories of 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' originate from Cheng Wuji's comparison of the Gancaoqianjiangtang and Shaoyaogancaotang in the 29th verse of the Shanghanlun. The two terms first appeared in the Qing period among the Wenbing school. In other medical texts, the combination with sweet flavors could be found with salty, bitter and bland flavors other than with pungent and sour. The role of the sweet flavor in 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' is to accomplish the dispersing and converging action slowly and effectively, by supplying energy in small amounts preventing it from happening too quickly, corresponding to its Earth nature of the Five Elements which harmonizes the Yin and Yang. While 'becoming Yin' and 'becoming Yang' could be understood as tonifying Yin and Yang, it could also be understood as 'doing Yin' and 'doing Yang', The specific actions differ according to herb and mixture. The point of distinction between the aforementioned tonification and that of medicinals that have Yin and Yang tonifying properties is that due to the other flavor that is matched with the sweet flavor, Qi is given motility which allows for tonification without stagnation.