In the previous post I mentioned dexter and sinister aspects. A reader left a message asking me to explain the concept, so here goes.
Lilly (CA 108) gives the following handy table to determine whether aspects are dexter (toward the right) or sinister (toward the left) from the perspective of the viewer on Earth, which is considered the center of the universe (we humans are such humble creatures):
To read this table, in the columns that lists “dexter” and “sinister” you find the sign of the body of the planet which is casting the aspect. For example, a planet in Aries will cast its dexter Ptolemaic aspects (to the right from the point of view of the observer on Earth) into the the signs Aquarius, Capricorn, Sagittarius and Libra. That same planet in Aries will cast its sinister aspectual rays into Gemini, Cancer, Leo and Libra. “Sinister” here refers to the left with reference to an observer on Earth.
In other words, dexter aspectual rays are cast in the same direction as the primary motion of the heavens. Sinister aspectual rays are cast against the direction of the primary motion of the heavens, which is the same as saying that they are cast in the same direction as the habitual secondary motion of the planets.
Lilly (CA 109) advises: “Observe the dexter aspect is more forcible than the Sinister.” Presumably this is so because dexter aspects occur in the same direction as the diurnal primary motion of the sky around the Earth.
In Hellenistic astrology, however, the sinister square of a planet in considered dominant. I believe this is so because a planet in sinister square to another has a 10th house relationship to the other planet and is considered much more elevated in status.
The concept of dexter and sinister is quite old and can be traced back at least to Hellenistic times. For example, Manilius in his poem about astrology from the time of Christ writes:
“Libram Capricornus et illum conspicit ante Aries atque ipsum a partibus aequis Cancer et hunc leava subeuntis sidera Librae.” (Astronomica, 2: 290-293)
My translation of this line from Manilius would be: “Capricorn beholds [aspects] Libra, while Aries looks at Capricorn ahead of him, and Cancer from an equal distance away casts its gaze at Aries, and the stars of Libra, which approach Cancer from the left, behold the sign of the Crab.”
In the standard “Aries rising” chart, Manilius would be saying that Capricorn at the top looks at Libra on the Descendant, and Libra looks at Cancer at the bottom of the chart, while Cancer looks at Aries on the eastern horizon. All the viewing is done in the dexter direction of the primary diurnal motion of the sky.