Ptolemaic Aspects

The fuller picture

Five angles, named for the second-century astronomer whose work codified them: the conjunction at 0°, the sextile at 60°, the square at 90°, the trine at 120° and the opposition at 180°. Every other angle you'll meet in modern astrology — the semi-sextile at 30°, the semi-square at 45°, the sesquiquadrate at 135°, the quincunx at 150° — sits outside the set.

That boundary isn't a matter of taste, because it's what the judgment rests on. Only these five count as a perfection, so only these five can turn a chart into a yes, and only these five produce a timing. Our engine does compute the minor aspects, and then deliberately filters them out of the perfection rules and out of the timing calculation. Keeping them visible and refusing to judge on them is the honest arrangement: you can see the whole geometry, and the answer only ever rests on the five.

Being "in aspect" depends on the pair as much as on the angle, which is the practical detail this list hides. Two planets are allowed the sum of their own orbs, which for the Sun and Jupiter runs to thirteen degrees. A planet to one of the four angles of the chart gets a fixed allowance by aspect type instead. A planet to a lunar node, to an Arabic part, to a fixed star or to a non-angular house cusp gets a conjunction only, and a narrow one. So the same three-degree gap is an aspect between two planets and nothing at all between a planet and a lot.

There are also ways two planets connect that aren't aspects. They can simply share a sign or a house, which our engine treats as a path to perfection in its own right — two significators in the same sign and the same house is the strongest testimony of connection there is. One significator arriving in the house belonging to the other side of the question is named in the source as a third route, listed alongside aspect and translation of light in the very rule that says when a matter fails. And antiscia are a fourth: mirror points across the solstice axis, where two planets are in contact without any of the five angles between them. We compute those and show them; the chart service that feeds our judgment leaves them out by documented design, so they inform your reading rather than the verdict.

One live departure is worth knowing about. The modern practitioner whose doctrine most of this glossary follows uses the quincunx, and says himself that it isn't a traditional horary consideration. His gloss is vivid — two planets that mix like oil and water and actively decline to see each other, rather than passively failing to — and he calls a quincunx between the two rulers of a marriage question a bad omen for the harmony the relationship can reach, whatever else intervenes. We don't admit it, as a perfection or as a denial. Worth adding that on his own worked charts he uses it to corroborate a conclusion he reached some other way, never to reach one, which is roughly where a careful reader should leave it.