Water

Water, shui, is one of the five phases of the Wu Xing, and like the others it is a phase in a dynamic cycle rather than a material element in the Greek sense. Water is associated with winter, the north, the colour black, the planet Mercury and the quality of maximum yin, stillness, depth, downward movement, and the potential held in reserve. In the generating cycle water is produced by metal and gives rise to wood (water nourishes plants); in the controlling cycle water is dammed and absorbed by earth and itself quenches fire.

In Chinese medicine water governs the kidneys and bladder, the emotion of fear, the ear and the bones, and it stores the jing, the essence held to be the deepest reserve of vitality. Water's symbolism is of depth, wisdom, the hidden and the stored, the deep pool and the winter earth holding the seed, and of the yin extreme of the cycle, the point of greatest stillness and inwardness from which, as the year turns, the upward wood phase of spring will emerge.

Sources Science and Civilisation in China, Volume 2: History of Scientific ThoughtJoseph Needham with Huangdi Neijing (The Yellow Emperor's Inner Classic)Traditionally attributed to Huangdi; actual authorship unknown

Water is the second name the Wu Xing shares with the Greek four elements, and as with Fire the shared word conceals a difference in kind. Shui is a phase, a position in a pair of cycles, and not a substance things are made from.

In the generating cycle, sheng, Metal produces Water and Water produces Wood, so water stands between the phase of contraction and the phase of new growth. In the overcoming cycle, ke, Earth restrains Water and Water restrains Fire. The pairing with Fire is the one the tradition works hardest, because Water and Fire sit directly opposite each other and the internal alchemy of the neidan schools is largely concerned with getting them to change places.

In the classical Chinese medical literature Water is the phase of the kidney and the bladder, of the ears, of the bones and the marrow, of winter, of the north, of the colour black, of the salty flavour and of fear among the emotions. It is also the phase associated with the stored reserve, the jing, which the texts treat as finite. These are correspondences internal to that system, recorded here as description and not as guidance.

Winter, the north, black, midnight and stillness form the cluster, and the reading is not of emptiness but of what is held below the surface until the cycle turns. That is the same logic the Daodejing uses when it praises water for taking the low place and wearing down what is hard.

Sources Science and Civilisation in China, Volume 2: History of Scientific ThoughtJoseph Needham with Huangdi Neijing (The Yellow Emperor's Inner Classic)Traditionally attributed to Huangdi; actual authorship unknown, Tao Te ChingLaozi (attributed)