Ren is the ninth of the ten Heavenly Stems (tiangan). Its element is Water and its polarity is yang, so Ren is glossed as yang Water, likened in tradition to the sea, a great river, or flowing water, broad, powerful, and moving. As one of the ten stems it combines with the twelve Earthly Branches to form the sexagenary cycle of sixty that numbers years, months, days, and double-hours in the traditional calendar. The stems run in fixed order, each carrying one of the five phases in a yang or yin form, and Ren brings the yang aspect of Water after the two Metal stems. These are the conventions of the Chinese calendrical and cosmological tradition, used in the almanac and in the four-pillars method of reading a fate from a birth.
Ren is the ninth Heavenly Stem, the first of the pair carrying the Water phase, and as an odd-numbered stem it takes the Yang polarity, traditionally likened to the ocean or a great river in flood, powerful and moving in volume, against Gui's Yin Water, likened to rain, dew or a still pool. Water closes the generating cycle of the five phases, condensing from Metal and nourishing Wood in turn, and in the controlling cycle it quenches Fire while being checked itself by Earth. Within the sixty-term sexagenary cycle, Ren combines only with Yang-polarity Earthly Branches: Rat, Tiger, Dragon, Horse, Monkey and Dog. In four pillars (BaZi) astrology a Ren day master is read as expansive, intelligent and hard to contain, prone to overflowing whatever channel is set for them unless balanced by Earth in the rest of the chart. The stem also names the ninth position in traditional Chinese ordinal lists.