Intercourse of Dragon and Tiger
In ancient China, “Dragon” and “Tiger” used to act as two of the four mysterious animals, which were the emblems for the 28 Stellar Spirits ( 二十八星宿 ershiba xingxiu ) Among them, the “Blue Dragon” stood for the Seven Stellar Spirits of the east, and the “White Tiger” symbolized the Seven Stellar Spirits of the west. In ancient China, “east” also stood for Yang, and “west” for Yin. Accordingly, the image of the two animals was linked to Yin or Yang separately. Among ordinary Chinese, “Dragon” and “Tiger” were developed into symbolic images for “male” and “female” separately. As a result, the marriage between a man and a woman used to be known as a relation between a dragon and a tiger. In Daoist theories about the Golden Elixir, the symbolism of the “Dragon” and “Tiger” was popularly used and further developed. In books on Outer Alchemy, the “Dragon” became the symbol of Lead, and “Tiger” the symbol of Mercury. In the later period, when the theory of Outer Alchemy was borrowed by scholars of Inner Alchemy, accordingly, the “Dragon” and “Tiger” became symbols for elements in the refinement of Inner Alchemy: “Dragon” used to act as a metaphor of Spirit or Spiritual Nature, and “Tiger” as a metaphor of Vital Breath or Desire. According to the Direct Pointers to the Great Elixir ( 《大丹直指》 dadan zhizhi ) by Qiu Chuji, “Dragon” was also known as the “Vital Breath of True Yang” ( 正陽之氣 zhengyang zhiqi ), and “Tiger” as the “Water of Perfect Oneness” ( 真一之水 zhenyi zhishui ). Patriarch Qiu said that the “Vital Breath of True Yang” referred to the Vital Breath “Bing”, which existed in “Mind Water” ( 心液 xinye ). Since “Bing” was a representative of Yang in the 12 Celestial Trunks , the “Vital Breath of True Yang” was also known as the “Yang Dragon”; the “Water of Perfect Oneness”, on the other hand, referred to Water “Gui”, which existed in the “Vital Breath of Kidney”. In the 12 Celestial Trunks ( 天干 tiangan ), “Gui” was the emblem of Yin. Accordingly, the “Water of Perfect Oneness” was known as “Yin Tiger”. In ancient China, the “Intercourse of Dragon and Tiger” was used to symbolize a harmonious relation between “Kidney Water” ( 腎水 shenshui ) and “Vital Breath of Mind” because “Mind” belonged to “Fire”, and “Kidney” belonged to “Water”, according to the theory of the “Five Agents” ( 五行 wuxing ). In later periods, it was borrowed to describe a sexual intercourse between a man and a woman, which, the ancient scholars argued, demonstrated a common principle: a stress over a harmonious and complementary relationship between Yin and Yang, the fundamental elements in the Universe..