Dexter Aspect (Right-Hand)

Definition

In traditional aspect doctrine, a dexter aspect is one cast backward — clockwise, against the direction the signs run. A planet aspects dexterly when it "looks back" toward signs that come before it in the zodiac. The Greek term is dexios, "right," and the Latin dexter also means "right." A planet in Aries casts a dexter sextile to one in Aquarius, a dexter square to one in Capricorn, a dexter trine to one in Sagittarius. Its opposite direction is the sinister, or left, aspect.

In Tradition

In Hellenistic and traditional medieval practice, the dexter aspect is the favoured, stronger form of any aspect other than the opposition — the planet casting it stands in the higher "tenth-place" position and is therefore read as overcoming the other planet. Holden records the standard valuation: "the right aspects were considered to be more favorable than the left aspects." This ranking belongs to the older sign-based framework, where an aspect is a directional act of looking rather than a symmetric geometric relationship.

In Practice

Astrologers working in traditional or Hellenistic-revival modes look, for each non-opposition aspect pair, at which planet casts the dexter (right) aspect and which the sinister (left). The dexter-casting planet is read as the stronger one in the configuration and as overcoming the other — especially in squares, where Crane gives the rule: "for any square, the planet in a tenth-place position has dominance over that planet." Modern Western practice, with strictly degree-based symmetric aspects, mostly loses this distinction, but it survives in horary, electional, and Hellenistic-revival work, where the asymmetry matters for telling which of two aspecting planets will dominate the result.

Historical Origin

The dexter/sinister doctrine is attested across the Hellenistic, Arabic, and Latin medieval literature. Crane keeps the Greek vocabulary (dexios/aristeros) and the doctrine of overcoming (kathuperteresis). Holden cites the standard valuation that right aspects are more favorable than left. The doctrine was carried by William Lilly's Christian Astrology (1647) — Crane notes Lilly explicitly values dexter aspects above sinister — and by the Arabic-Latin medieval tradition, with Al-Biruni's Tafhim cataloguing both terms and Bonatti's Liber Astronomiae preserving the directional doctrine.

Further Reading