Nei chia
Nei chia (內家 pinyin nei4jia1) denotes the internal, or 'soft' family of Chinese martial arts . Traditionally, the three arts Tai Chi Chuan, Bagua zhang (Ba Gua Quan) and Hsing Yi[?] (Xing-i) are regarded internal.
This classification was first identified in the 1920s by the Chinese philosopher Sun Lutang[?]. According to this classification, the principles defining an internal martial art are: