Water was one of many archai proposed by the Pre-socratics, most of whom tried to reduce all things to a single substance. However, Empedocles of Acragas (c. 495-c. 435 BC) selected four archai for his four roots: air, fire, water, and earth. Empedocles’ roots became the four classical elements of Greek philosophy. Plato (427-347 BC) took over the four elements of Empedocles. In the Timaeus, his major cosmological dialogue, the Platonic solid associated with water is the icosahedron which is formed from twenty equilateral triangles. This makes water the element with the greatest number of sides, which Plato regarded as appropriate because water flows out of one's hand when picked up, as if it is made of tiny little balls.
Plato’s student Aristotle (384-322 BC) developed a different explanation for the elements based on pairs of qualities. The four elements were arranged concentrically around the center of the Universe to form the sublunary sphere. According to Aristotle, water is both cold and wet, and occupies a place between air and earth among the elemental spheres.
In ancient Greek medicine, each of the four humours became associated with an element. Phlegm was the humor identified with water, since both were cold and wet. Other things associated with water and phlegm in ancient and medieval medicine included the season of Winter, since it increased the qualities of cold and moisture; the phlegmatic temperament (of a person dominated by the phlegm humour); the feminine; the brain; and the western point of the compass.
In Hindu philosophy, the term refers to water as an element, one of the Panchamahabhuta, or "five great elements". In Hinduism, it is also the name of the deva, a personification of water, (one of the Vasus in most later Puranic lists). The element Water is also associated with Chandra or the Moon, and Shukra or Venus, who represent feelings, intuition and imagination. Water is also linked to the north east direction.
Water is yin or feminine in character, its energy is downward and its motion is stillness and conserving. It is associated with the planet Mercury, the north, winter and cold, darkness, night and the colour black. It is also associated with the moon, which was believed to cause the dew to fall at night. It is also believed to govern the kidneys, ears and bones. The negative emotion associated with water is fear, while the positive emotion is calmness. Its Primal Spirit is represented by the Black Tortoise.
In Chinese Taoist thought, water is representative of intelligence and wisdom, flexibility, softness and pliancy; however, an over-abundance of the element is said to cause difficulty in choosing something and sticking to it. In the same way, Water can be fluid and weak, but can also wield great power when it floods and overwhelms the land. In the birth and nurturing cycle, water spawns wood, and is spawned by metal. In the conquest cycle, water overcomes fire, and in turn is overcome by earth.
Water also plays an important role in Chinese Astrology. In Chinese astrology water is included in the 10 heavenly stems (the five elements in their yin and yang forms), which combine with the 12 earthly branches (or Chinese signs of the zodiac), to form the 60 year cycle. Yang water years end in 2 (eg 1992), while Yin years end in 3 (eg 1993). Water governs the Chinese zodiac signs Pig, Rat and Ox.
The manifestations of the element of water are rivers, oceans, lakes, wells, fog, all drinks, and the rain. Animals, especially the dolphin, seal, turtle, frog, and all types of fish, are also thought to personify the element of water. The astral creatures of water, known as elementals, are the Ondine/Mermaid, Oreade/Naiad, and Sea Serpent/Dragon. Water’s place on the pentagram is the upper right point.