Pisces — 2nd Decan (10°–20°)
The second decan of Pisces covers 10° to 20° of the sign, the middle of the sequence that closes out the zodiac's 36 decans. The two rulership systems diverge here again: Triplicity points to the Moon, the Chaldean system points to Jupiter.
Last reviewed: 2026-07-20
Historical fact
Like every decan, this 10° segment originates in the ancient Egyptian decan system — the 36 small constellations that, rising successively on the horizon roughly every ten days, served as a nighttime star clock documented from around 2100 BCE, long before their merger with the 12-sign zodiac in the Hellenistic period, when each sign gained 3 decans of 10° with their own rulers. Pisces, the last sign of the zodiac cycle, has in this second decan the midpoint of the trio that closes out the 36 decans before the cycle restarts at Aries. The two assignment systems keep diverging: under Triplicity, the ruler is the Moon; under the Chaldean system, it's Jupiter.
Interpretation — Triplicity System (Modern Astrology)
In Triplicity, the second decan of any Water sign is ruled by the next same-element sign's ruler in zodiacal order — for Pisces, that's the Moon, ruler of Cancer. The reading combines Pisces' imaginative fluidity with the Moon's typical emotional sensitivity, protective instinct and need for closeness, resulting in energy even more turned toward the inner world, emotional memory and care for others.
Interpretation — Chaldean System (Hellenistic Tradition)
In the Chaldean system's continuous cycle, after Saturn in the previous decan, the next ruler in the sequence of 7 classical planets is Jupiter — the same planet that rules Pisces' 1st decan under Triplicity, now reappearing here under the Chaldean system. This reading expands Pisces' sensitivity with Jupiter's typical expansion, optimism and search for greater meaning, softening the lunar introspection that marks Triplicity's reading for this same degree range.
This section presents one tradition's interpretation, not a verifiable fact.
Frequently asked questions
- Does Pisces' 2nd decan have the same ruler in both systems?
- No. Under Triplicity, the ruler is the Moon; under the Chaldean system, it's Jupiter. The two rulership assignment systems diverge across nearly all of Pisces' decans, coinciding only at the 3rd and final one.
- What changes between Pisces' 1st and 2nd decan?
- The 1st decan, ruled by Jupiter (Triplicity) or Saturn (Chaldean), swings between Jupiter's expansion and Saturn's seriousness. The 2nd, ruled by the Moon (Triplicity) or Jupiter (Chaldean), adds a layer of emotional sensitivity and nurturing — or repeats Jupiter's expansive note, depending on which system you follow.
Sources
- Nicholas Campion. A History of Western Astrology (2009).
- Claudius Ptolemy. Tetrabiblos (c. 150).
- Vettius Valens. Anthology (Hellenistic astrology) (c. 175).
- Otto Neugebauer, Richard A. Parker. Egyptian Astronomical Texts (1960).