The "Terms" of the Zodiac Signs

Each zodiac sign is subdivided in five segments of variable size, and each of the segments is "ruled" by a planet. These segments are called the "terms" or "limits" or "bounds" of the sign. (Latin finis and terminus, Greek ὅριον)

Astrodienst offers the following four methods of the terms in the "Extended Chart Selection":

Egyptian Terms

12° 20° 25° 30°
14° 22° 27° 30°
12° 17° 24° 30°
13° 19° 26° 30°
11° 18° 24° 30°
17° 21° 28° 30°
14° 21° 28° 30°
11° 19° 24° 30°
12° 17° 21° 26° 30°
14° 22° 26° 30°
13° 20° 25° 30°
12° 16° 19° 28° 30°

Chaldean Terms

Attention! With night births, Mercury and Saturn are exchanged in this system.
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°
15° 21° 26° 30°

Ptolemean Terms (Lilly)

14° 21° 26° 30°
15° 22° 28° 30°
14° 21° 27° 30°
13° 20° 27° 30°
13° 19° 25° 30°
13° 18° 24° 30°
11° 16° 24° 30°
13° 21° 27° 30°
13° 18° 24° 30°
13° 19° 24° 30°
12° 20° 25° 30°
15° 21° 26° 30°

Ptolemean Terms (Houlding)

Ptolemaean Terms according to Deborah Houlding, see explanations further below.

14° 21° 26° 30°
15° 22° 28° 30°
14° 21° 27° 30°
13° 20° 27° 30°
13° 19° 25° 30°
13° 18° 24° 30°
11° 19° 24° 30°
13° 21° 27° 30°
13° 18° 24° 30°
13° 19° 24° 30°
12° 20° 25° 30°
15° 21° 26° 30°

The transmission history of the Ptolemaean Terms is unfortunately very complicated. Several different versions of them have appeared over the centuries. The current version, which goes back to William Lilly, is just one of them. Deborah Holding has made an attempt to reconstruct the original Ptolemaean Terms based on some logical principles from which they may have been derived.

Sources:
Deborah Houlding, "Ptolemy's Terms & Conditions", 2007, http://www.skyscript.co.uk/pdf/Houlding_ptolemy_terms.pdf
F.E. Robbins, "Ptolemy - Tetrabiblos", Greek and English, 1980, p. 106.
W. Lilly, "Christian Astrology" (1647), p. 104.

Back to the overview list