Bicorporeal Signs

Definition

Gemini, Virgo, Sagittarius, and Pisces — the four signs that close each seasonal quadrant of the zodiac, also called 'common' or, in modern usage, 'mutable' signs. The name 'bicorporeal' ('two-bodied') comes from their iconography: each sign is represented by a pair or a composite figure — twins, virgin holding an ear of wheat, centaur-archer, two fishes — distinct from the tropical signs (cardinal, single-image) and the fixed signs (single-image, stable).

In Tradition

Across Hellenistic, Arabic-Persian, and Western tradition, the bicorporeal signs are read as the modality of mixture and transition: the place in each quadrant where one season's nature gives way to the next, where qualities are doubled or compounded, where outcomes are multiple rather than singular. The threefold classification (tropical / fixed / bicorporeal) is one of the basic modal divisions of the zodiac.

In Practice

When the bicorporeal modality is implicated in a chart — a stellium in mutable signs, a mutable rising sign, a planet in a bicorporeal sign in a critical place — astrologers read it as duality, manifoldness, or doubled outcomes. Dorotheus uses the class throughout Book II of the Carmen as a multiplier-of-manifestations modifier: Jupiter in a bicorporeal Ascendant yields two names (named after the parents); Venus in a bicorporeal Ascendant yields two fathers, two mothers, or two names; Mercury in a bicorporeal sign makes him a trainer or guardian of a child not his own. The doctrine operates independently of sign sect, gender, or element — it is purely a modality modifier.

Historical Origin

The threefold tropical/fixed/bicorporeal classification is Hellenistic in origin, codified by Ptolemy in Tetrabiblos I.11 and used throughout Dorotheus's Carmen Astrologicum (1st c. CE). The Arabic reception renders the Greek δίσωμα (disōma) literally as dhū jasadayn ('one having two bodies') or dhāt jasadayn, attested in Abu Ma'shar's Great Introduction Part II Ch 6 and throughout the Arabic-Latin corpus. The medieval Latin reception uses signa bicorporea; the modern English label 'mutable' is a later replacement carrying the same threefold logic.

Etymology

Origin: Latin / Greek / Arabic. Meaning: Two-bodied.

Further Reading

• Dorotheus of Sidon, Carmen Astrologicum
• Abu Ma'shar, Great Introduction to Astrology
• Claudius Ptolemy, Tetrabiblos