The Latin word "termini" means limits, confines - i.e. not a single degree but an area.
In Hellenistic times the terms were called hories.
Traditionally, each sign is divided into five sections of unequal length. One of the five traditional planets (excluding the sun and moon) rules each of these sections. A planet within the segment that it rules is in its own terms.
The terms are one of a planet's essential dignities. They depend on its placement in the Zodiac, irrespective the Houses. Nowadays the terms still are used in Horary Astrology and in Electional Astrology. Not very often, though, because their system is not so simple and logical as the Decans. And because in the meantime we have several, slightly different systems:
Al-Biruni's Egyptian Terms
The Persian-Arabian astrologer Al-Biruni's terms are based (mainly) on those of Firmicus Maternus and can be found in the Tetrabiblos, 1.20.
|Sign||Egyptian Terms according to Al Biruni|
Lilly's Ptolemean Terms
Hellenistic astrologers argued quite early about the "correct" terms. Lilly called his sytem - which among astrologers widely was accepted since the Renaissance times - Ptolemaic, though actually its origin was not clear at all.
Chaldean Terms according to Ptolemy
(For night births you have to exchange Mercury and Saturn)
Ptolemean terms according to Houlding
- For calculation and depiction in the chart select the Traditional astrology option (Extended Chart Selection of Astrodienst)
- Ptolemy's terms & conditions (Houlding 2007/ 2010)
- Traditional Degree Influences (a.o. according to term and face; Houlding, 2006)
- Al Biruni & Arabic Astrology (David Plant, 1994)
Notes and References
- Cf. the "terminal" of an airport
- Chapter 1.20, see F.E. Robbins, Ptolemy. Tetrabiblos, 1980, pp. 90-97
- See Peter Stockinger's Traditional Astrology Weblog: A look at Tables of Essential Dignities and Debilities, Essential Dignities (Ptolemy) / The Egyptian Terms (Houlding), Firmicus Maternus Mattheseos Libri 2.6. and Robbins, pp. 90-97
- William Lilly, Christian Astrology, 1647, pp. 106. Source: Robbins, pp. 102-107. See more details on Skyscript, Ptolemy’s Terms & Conditions (Houlding)
- Robbins, pp. 98-101
- Deborah Houlding tried to reconstruct the terms' original logical system