Ren

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.

Every stem has a partner among the other nine, and the five pairings, called the combinations of the heavenly stems, are fixed: each stem combines with the one five places away from it. Ren pairs with Ding, and the tradition holds that a combined pair takes on a phase of its own distinct from either stem's native phase. The pairing is used in almanac work and in fate calculation, where a combination in a chart is read as a binding between the two positions that carry it.

The ten stems are older than the sexagenary cycle they now form half of. On the Shang oracle bones of the second millennium BCE they name the ten days of the xun, the Shang week, and Shang kings are known to history by posthumous names built on them, so a stem was a unit of the working calendar before it was a term of cosmological art. The five-phase and yin-yang readings attached to the stems are later, systematised under the Han, and the atlas records the two layers as two layers.

Ren is yang Water, conventionally the sea or the great river against the dew and rain of Gui. Water is the last phase in the generation order as the stems run it, generated by Metal and generating Wood, so the ninth and tenth stems lead directly back to the first and the cycle closes without a break.

The stem's own attributes here are Water and yang polarity. Those two facts fix its place in the run of ten, since the stems proceed through the five phases in generation order taking the yang member first and the yin member second, and they fix how it is read wherever it appears, in the year, the month, the day or the double hour of a Four Pillars chart.

Sources Chinese Mathematical Astrology: Reaching Out to the StarsHo Peng Yoke with The Chinese Sexagenary Cycle and the Ritual Origins of the CalendarAdam Smith