The terms, six schools compared

Where each table comes from

Not “the tradition”: a name, a book, and the caveat where there is one. A reference table that will not say whose figures it carries is asking to be taken on trust.

Egyptian terms Used by this site

The oldest and by far the most widely followed table: six authors, four languages and eleven centuries hand it down unchanged, from Greek Alexandria to Hebrew Provence.

Witnesses: Vettius Valens, Firmicus Maternus, Abu Ma'shar, Alcabitius, Al-Biruni, Ibn Ezra

No single edition carries the authority: the source is the agreement between the Greek, the Latin, the Arabic and the Hebrew.

This is the table the site uses, and it is worth two points of essential dignity in every chart. It lands exactly on the planetary years, which is the check the tradition itself proposes.

Ptolemy, critical edition

Ptolemy says he recovered an old and damaged manuscript, and publishes its table against the Egyptian one. Robbins established that text in 1940 from a Vatican manuscript, before the Renaissance corrections of usage.

Witnesses: Claudius Ptolemaeus

Source: Tetrabiblos I.20 (Robbins, Loeb 1940), Vaticanus graecus 1453

Of the two readings of Ptolemy, this is the only one that lands on the planetary years, which is precisely the property Ptolemy claims for his manuscript. A textual argument as much as an arithmetical one.

Ptolemy, Lilly's vulgate

The table Lilly printed in 1647 after Cardan and Junctinus, and the one most software carries today under the label “Ptolemy's terms”.

Witnesses: William Lilly, Hieronymus Cardanus, Franciscus Junctinus

Source: Christian Astrology (Lilly, 1647), p. 104

Seven boundaries separate it from the critical edition, across seven signs, that is sixty-six degrees of disagreement. And it misses the planetary years by one degree: Jupiter 80 instead of 79, Mars 65 instead of 66. Little enough to go unnoticed for four centuries, enough to change a ruler.

Hephestio of Thebes Transcription to be checked

The oldest independent witness after Ptolemy, in the fifth century, and the branch through which the terms pass into Arabic astrology.

Witnesses: Hephaestio Thebanus

Source: Apotelesmatika I.1 (ed. Pingree)

Taken from a reproduction of Pingree's critical edition rather than from the edition itself: it is the one table here whose transcription has no outside check, since it does not land on the planetary years either. We say so rather than serve it at the same rank as the others.

Chaldean, day Day birth

Here Ptolemy gives a rule and not a diagram: widths always 8, 7, 6, 5 and 4 degrees, the first term to the ruler of the sign's triplicity, then on from triplicity to triplicity.

Witnesses: Claudius Ptolemaeus

Source: Tetrabiblos I.21 (Robbins, Loeb 1940)

This table is not copied, it is rebuilt from the rule. The check is a fine one: the totals that come out are exactly those Ptolemy states in Greek numerals in the same chapter.

Chaldean, night Night birth

The same rule, with Saturn and Mercury swapped wherever both appear: the airy triplicity has two rulers, and which of them goes first depends on the sect.

Witnesses: Claudius Ptolemaeus

Source: Tetrabiblos I.21 (Robbins, Loeb 1940)

The whole difference between the two Chaldean tables lies in that swap, and it is enough to exchange their two totals, 78 and 66, while the other three stay put.

What we do with them

We use the Egyptian terms, and we use them everywhere: they are worth two points of essential dignity in the calculation that weighs every planet in your chart, and they feed the almuten. This is not convenience. It is the table six authors in four languages agree on, the only one that never had a rival version inside its own tradition, and it lands on the planetary years.

We offer no switch to another school. One birth would then yield two charts, and you would have no way to decide between them: that would be handing you a scholars' quarrel dressed up as a setting. The choice is made, it is written here, and this page gives you what you need to argue with it.

Where the sources diverge, we say so instead of quietly picking one. The two tables “of Ptolemy” are the clearest case: most software carries Lilly's without knowing another exists, closer to the manuscript, and that it is the other one that passes the check Ptolemy himself proposes.

Author names and edition references stay as they are in every language on the site: they are proper names and bibliographic citations, and the abbreviations used are Latin for that very reason. “Claudius Ptolemaeus” reads everywhere; “Ptolemy” on a German page would be carelessness.

The system this page does not show

In his Anthology, Vettius Valens describes a seventh division: seven terms per sign instead of five, luminaries included, their widths equal to the number of dignities each body holds (Sun 3, Moon 4, Saturn 4, Mercury 4, Jupiter 5, Mars 5, Venus 5, making 30). It does not fit a five-column grid, and above all Valens never uses it: in his own worked examples he takes the Egyptian terms. A documented theoretical variant, then, not a school in use. We cite it here rather than let it into a table where it would pass for one more school actually in practice.