Twelfth-Parts | 2. The Secret Second Chart

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Secret Charts

For, if you want to explain the entire substance of the astrological significations from the efficacy of the dodecatemories and from the terms in which they are found, you will not be mistaken; for the Babylonians attribute the supreme power of [astrological] decrees to the dodecatemories, but Ptolemy to the antiscions, [and] we to both.  (Maternus, Book III, Ch. 9, #14, Holden trans., 2011, p. 170)

So, you thought you just had one astrological chart, but in Hellenistic astrology you have two.  Then again, maybe three. The secret charts are found by examining some projected positions for chart factors.


The second chart I allude to is the chart of the twelfth-part positions. Twelfth-part positions were noted as a fundamental basic of astrological technique by nearly every Hellenistic astrologer. Their use was urged most strongly by Julius Firmicus Maternus. These are typically marked along the natal chart to keep a reference to natal chart houses.  I explored what the twelfth-parts are and how they are calculated in the introductory article.


The third chart that I alluded to is something that appears to be more idiosyncratic to Maternus. It is the use of antiscia positions as yet another chart body-double.  I explored this use of antiscia by Maternus very briefly near the end of my article on sign symmetry.

Maternus attributes this use of antiscia chart positions as secret positions to Ptolemy, though this is a false attribution. Maternus is the only Hellenistic source I know of that uses this third set of positions.  On the other hand, the dodecatemoria or twelfth-parts are indeed Babylonian in origin, and their use was widespread among Hellenistic astrologers.

Paulean Twelfth-Parts

In the last article, I expressed that Paulus presented an idiosyncratic variety of twelfth-parts in which the position in degrees and minutes are multiplied by 13 rather 12. I was recently confronted by a footnote by James Holden (footnote #2, p. 18, 2009) in his translation of Rhetorius in which he noted that there is evidence in surviving cuneiform tablets that the two different methods of projecting twelfth-parts existed in Babylonian astrology. In other words, according to Holden multiplying by either the more common 12 or the 13 as used by Paulus, then projecting from the beginning of the sign, were both used (Holden cites “Mesopotamian Astrology” by Koch-Westenholz).

If it is in fact the case that the 13-fold variety does also have Babylonian origins, then at least among the Hellenistic astrologers, it was a less popular variant. Manilius, Dorotheus, Ptolemy, Valens, Maternus, Hephaistio, Porphyry, and Rhetorius (as well as later astrologers) employed or expressed preference for the 12-fold variety.

The Importance of the Twelfth-Part Positions

I was originally skeptical about the use of the twelfth-part positions. I didn’t think they represented an important or informative addition to the natal chart positions. I’m sure many readers initially feel the same way.  Therefore, I want to stress that the twelfth-parts were mentioned as a basic of astrological technique by nearly every Hellenistic astrologer. Many of them, including Manilius, Maternus, and Rhetorius, felt it necessary to stress how important they are despite how easy it is to overlook them.

… the genitures differ in a single constellation, because the individual signs vary on account of the distribution of their divisions and modulate their respective powers in the dodecatemories.  (Manilius, Book II, #710-712, Goold trans., 1977, p. 139)

And the method of dodecatemories is a necessity in nativities; and I also put down the astrological significations of these so that some might use them not just as in a secondary work.  (Rhetorius, Ch. 18, Holden trans., 2009, p. 18)

Now I shall show briefly how you may inquire about the dodecatemories, for some think that they can find the entire substance of the nativity from them, and they intimate that whatever is concealed in the delineation can be discovered from the dodecatemories.  (Maternus, Book II, Ch. 17, #1, Holden trans., 2011, p. 59)

Basics of Use

The twelfth-part positions are used just like natal positions. They give additional information and reveal significations that might be missed from looking at the natal chart alone.

Cognition Usage Isn’t Just About Cognition

Even the interpretation of cognition usage (discussed in the last article) is along these lines, though it is for horary or consultation charts.  Masha’allah (in On Hidden Things) discussed multiple signficators for the querent’s thoughts or intentions. One of them was the ruler of the Ascendant. However, Masha’allah expressed that the best significator is the twelfth-part of the Ascendant and its ruler. In other words, the twelfth-part Ascendant and its ruler are used just as the Ascendant and its ruler to give information about the querent and the matter itself.

Hellenistic Astrologers Using Twelfth-Parts as the Secret Chart

Paulus: Twelfth-Parts Also Show Benefic/Malefic Indications

We get a sense of this all-purpose use in Paulus, even though he used the 13-fold ones. In Ch. 22 of his Introduction, he noted that the twelfth-parts of benefics occurring in important places signify very good things for the person. By contrast, twelfth-parts of malefics occuring in such places indicate bad things. Benefics produce fortunate circumstances where they occur, and malefics produce difficulty, and it is the same with the twelfth-parts of each.

Maternus: Delineation of a Planet or Point Includes Delineating its Twelfth-Part

Maternus laid out the use of twelfth-parts in Book II of the Mathesis.  There he instructed us to look at numerous things but stressed the place, the ruler, and the bound ruler of the twelfth-part. We are are also to look at sect and the interactions between planets in ways that he discussed for regular planets (for instance that there is greater harmony between the waxing or full moon and diurnal planets).  All in all, it seems that Maternus wants us to look at twelfth-part positions as on an almost equal footing as natal positions, examining things like place, sign ruler, bound ruler, regards/aspects, and special configurational indications.

This is further stressed in Book III, when each chapter on a planet ends with Maternus admonishing the reader to also check out the planet’s twelfth-part. Apparently, we are to look at the same factors discussed with reference to the natal planet. In this way we will not miss some important indication that is in the twelfth-parts but not the regular natal chart, as everything should be in one or the other.  Maternus even advised to check the twelfth-part of the Lot of Fortune after discussing Fortune’s delineation  (Book IV, Ch. 4) .  Again, the clear lesson is to delineate the twelfth-part as you’d delineate the planet.

Rhetorius: Twelfth-Part Positions Signify in Configurations Too

But what of the relationship of a twelfth-part to its same natal point, such as the twelfth-part of the Sun to the natal Sun?  Rhetorius treated of this in Ch. 60 of his Compendium.  A twelfth-part trine its natal position increases the beneficence or fortune signified by the planet, but one opposed to its natal position increases the maleficence or difficulty signified by the planet.

Rhetorius also discussed how the twelfth-parts of malefics falling in places can make things more difficult and the twelfth-parts of benefics easier, similar to what Paulus mentioned above.  He put particular stress on the twelfth-part of the Moon in relation to the nature and social standing of the person.  In his delineations of twelfth-parts he particular stressed the influence of the ruler of the twelfth-part. Some delineations also involve regards/aspects from natal planets and even the qualities of the signs, such as human and quadrapedal.  That the twelfth-part delineations of Rhetorius encompassed all these things lends support to the idea that delineation of the twelfth-part is very much like delineation of a natal planet or point.

Delineation Example: Steve Jobs

In the next several posts on twelfth-parts, I’ll be digging back to analyses from older posts on the blog and showing how twelfth-parts add valuable information.  I will kick this off by taking a brief second look at the chart of Steve Jobs for the rest of this post.

In one my first posts, in October 2011, I discussed the natal chart of Steve Jobs and some of the most important general planetary strength considerations, showing that his Mercury is much stronger than one might think from a cursory glance.  Before reading on, I urge the reader to give that post a quick review by visiting it here.  While stations and phasis may not be appropriate to twelfth-parts, the twelfth-parts can tell us additional information about the strength of Mercury.

Steve Jobs' Natal Chart with Twelfth-Parts on Outer Wheel
Steve Jobs’ Natal Chart with Twelfth-Parts on Outer Wheel

In the original analysis I noted that Mercury is probably the strongest planet in the chart in terms of having a generally pervasive influence over the life in a broad way, as it is strongly stationing direct, making an appearance (in phasis), advancing, and ruling the 1st.

Twelfth-Part MC Conjunct nMercury; Twelfth-Part Mercury Strong

Looking at the twelfth-parts we find further indication of the significance of Mercury by the twelfth-part of the MC being conjunct Mercury.  This and the fact that Mercury’s twelfth-part is advancing in the 11th which is a strong and fortunate place. It is in a sign of a light (Cancer, home of the Moon, which is the sect light of the chart), while actually with the twelfth-part of the sect light. These are all additional indications of the strength of Mercury.

Twelfth-Part Mercury Fortunately Conjunct nJupiter

The twelfth-part of Mercury is in the bound of Jupiter (as is the natal Mercury), and is very tightly conjoined to Jupiter, in the place of Jupiter’s Joy, and in the sign of Jupiter’s exaltation. These things all connect Mercury with fortunate and lofty Jupiterian themes, but are not as strongly expressed in the natal chart itself.

Mercury posited in the 11th house from the ASC will make talented persons, indispensable for all activities, and those to whom the conduct of great business affairs is entrusted; but then it denotes greater duties if it was conjoined to Jupiter by a favorable aspect.  (Maternus, Book III,Ch. 3f, #23, Holden trans., 2011, p. 147)

More Twelfth-Parts

The twelfth-part of Venus, the sect benefic, occupying Virgo, a house of Mercury, further emphasizes this fortunate quality of Mercury.  Also note that the twelfth-part of Jupiter falls right onto the Sun in the chart. The twelfth-part of the Sun is in the place of the Sun’s Joy with the twelfth-part Ascendant. The Moon’s twelfth-part is strongly advancing toward the MC. She is also with the lord of the Ascendant and Jupiter (as well as Saturn).  Additionally, the twelfth-part of Fortune is conjunct the Moon, the sect light.

Key Information

As one can see, the twelfth-parts not only help us to get more information out of the chart about the prominence of Mercury, but also showcase fortunate circumstances connected to Mercury. These are important features of this person’s life that are reflected in the chart with the twelfth-parts but would be easy to miss from the natal chart without them. We see many additional indications that the chart is of someone with great social mobility and very fortunate circumstances linked to Mercury.


Twelfth-parts are not a trivial matter. In chart delineation, it is vital to see which indications are repeated in many different ways. Such indications are stronger and more important, allowing us to say something meaningful about the life. The twelfth-parts are a vital and important part of chart delineation. If you’re looking at a chart without the twelfth-parts, you are missing a huge chunk of the information in the chart. Without this important information, you can rest assured that you will reach the wrong conclusions. Similar indications of something in the chart may be repeated without your knowledge while other indications you might think are important may be contradicted by the twelfth-parts. If you’re serious about accurately reading a natal chart add the twelfth-parts to your chart readings today.

Manilius, M. (1977). Astronomica. (G. P. Goold, Trans.). Cambridge, MA: Loeb Classical Library.
Maternus, J. F. (2011). Mathesis. (J. H. Holden, Trans.). American Federation of Astrologers.
Rhetorius of Egypt, & Teucer of Babylon. (2009). Rhetorius the Egyptian. (J. H. Holden, Trans.). Tempe, AZ: American Federation of Astrologers.


Blogger interested in all things astrological, especially Hellenistic, medieval, Uranian, and asteroid astrology.

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