In Chinese philosophy, water (Chinese: 水; pinyin: shuǐ), is the low point of the matter, or the matter's dying or hiding stage. Water is the fifth stage of Wu Xing, the five elements. Water is the most yin in character of the five elements. Its motion is downward and inward, and its energy is stillness and conserving. Water is associated with certain colors, with the planet Venus, with the moon (which was believed to cause the dew to fall at night), with night, with the north, with winter or cold weather, and with the Black Tortoise (Xuan Wu) in the Chinese constellation Four Symbols.