The doctrine of moiety: mondorla

Mondorla. Pencil and pastel on paper. Tomek Kalamaya 01.22.2026

“The Arabic/Medieval tradition assigned (planetary) orbs in the determination of aspects. The orbs were not associated with the individual aspects, but rather with each of the planets based upon the distance of the orbs of light that emanated from each planet. The Sun has an orb of 15°, the Moon 12°, Mercury 7°, Venus 7, Mars 8, Jupiter 9°, and Saturn 9°. Known as the doctrine of moiety, an aspect between two planets becomes effective when the two orbs are added together, and then halved to obtain a mean value that applies to both. This moiety sets the range that the planets actual distance can deviate from the exact aspect whereby the planets have a valid interaction. Therefore, each set of planets has its own orb of connection.” Demetra George Ancient Astrology In Theory and Practice, Vol. 1 pg 390.