The Hermetic lots (Arabic parts)
Hellenistic — Paulus Alexandrinus's Introductory Matters, citing the lost Panaretos
A lot projects the arc between two planets from the Ascendant to derive a sensitive point; the seven Hermetic lots are set out by Paulus Alexandrinus, and the Lot of Fortune is already central in Valens. 'Arabic parts' is a misnomer — Bonatti assumed they came from Arabia — since the lots are Hellenistic, securely attested from the 1st century CE.
What it measures
Each lot is Ascendant + one planet − another (for example Fortune = Asc + Moon − Sun by day). Equivalently, the lot is the reflection of one planet across the midpoint of the Ascendant and the other — an arc projected onto the wheel, not an average.
Where practitioners disagree
- Reverse the formula at night?
Reverse for night charts (ours) — or, following one reading of Ptolemy, do not reverse the Lot of Fortune
Most of the tradition reverses the day/night formulas; Ptolemy is read as an exception for Fortune.
This engine: Reversed at night (Fortune becomes Asc + Sun − Moon), matching the chart's own Fortune and Spirit points.
Sources
- Paulus Alexandrinus (trans. R. Schmidt), Introductory Matters (1993)
- Vettius Valens, Anthology