Essential dignities
The Ptolemaic table of dignities — Hellenistic, formalised in Ptolemy's Tetrabiblos I (2nd c. CE)
Each sign carries rulerships on five levels — domicile, exaltation, triplicity, bound (term) and decan (face) — a scheme inherited from Babylonian and Egyptian practice and given its canonical Western form by Ptolemy. Ptolemy reasoned some assignments physically: he placed cold Saturn in the warmth of the day and dry Mars in the moisture of the night, so each malefic's excess is tempered by the opposite quality.
What it measures
How much a planet is 'at home' or 'in exile' by the sign and degree it occupies — a strength built from the five dignity levels, independent of the aspects.
Where practitioners disagree
- Whose table of bounds?
The Egyptian bounds (most widely attested) or Ptolemy's variant set
The two tables agree on only a minority of degrees, and the Ptolemaic degrees themselves vary between manuscripts.
This engine: The Egyptian (Ptolemaic-transmitted) bounds.
Sources
- Claudius Ptolemy, Tetrabiblos, Book I (2nd c. CE)