Antiscion

greek: ἀντίσκιον (antiskion, 'opposite shadow') · latin: antiscium

Definition

An antiscion (Greek antiskion, 'opposite shadow') is the mirror-image point of a planet across the solstitial axis — the line marking the Sun's turning points at the solstices. In the standard modern convention this axis runs through 0° Cancer / 0° Capricorn, so the antiscion of a degree is found by reflecting its longitude across that line: 10° Aries ↔ 20° Virgo, 5° Gemini ↔ 25° Cancer, and so on. Two planets whose degrees stand at each other's antiscia are read as connected as if by aspect.

In Tradition

In Hellenistic and traditional Western practice antiscia are treated as a kind of hidden aspect or sympathetic resonance carried by equal solar declination — two points equidistant from the solstice receive equal daylight and were read as sharing the Sun's virtue. Holden documents that Firmicus credits Ptolemy with favoring antiscia in three Mathesis passages, even though Ptolemy's own Tetrabiblos does not mention them.

In Practice

You compute an antiscion by subtracting the planet's longitude from 30° Cancer (or, equivalently, by reflecting across the 0° Cancer / 0° Capricorn axis). The contrantiscion is the point opposite the antiscion. Traditional astrologers read a tight antiscion contact — a planet sitting on another planet's antiscion within about 1° orb — as a concealed conjunction or opposition that thickens the chart's narrative without showing up on a simple aspect grid. The doctrine survives in modern horary practice and is closely related to the parallel of declination, since both rest on the same equal-declination geometry.

Historical Origin

The antiscion doctrine is attested in Firmicus Maternus's Mathesis (4th c. CE), where it is repeatedly credited to Ptolemy. Holden traces the historical development of the solstitial axis: earlier Eudoxan astronomy placed the solstices in mid-Cancer and mid-Capricorn, giving pairings like Gemini-Leo and Taurus-Virgo; after the Ptolemaic tables fixed the solstices at the sign beginnings the modern pairings (Gemini-Cancer, Taurus-Leo, etc.) became standard.

Etymology

Origin: Greek. Meaning: From anti- ('opposite') + skia ('shadow') — the 'opposite-shadow' point of a planet, the place where a gnomon-shadow at the antiscion latitude would mirror the original..

Further Reading