Twelfth-Parts | 2. The Secret Second Chart

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 second chart I allude to is the chart of the twelfth-part positions, which are typically marked along the natal chart, so as to keep the reference to natal chart houses.  Twelfth-part positions were noted as a fundamental basic of astrological technique by nearly every Hellenistic astrologer, and their use was urged most strongly by Julius Firmicus Maternus.  I explored what the twelfth-parts are and how they are calculated in my last post.  The third chart that I alluded to is something that appears to be more idiosyncratic to Maternus, and 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 post on sign symmetry.

In the quote above, Maternus attributes this use of antiscia chart positions as secret positions to Ptolemy, though this is a false attribution, and 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.

While in my last post I expressed that Paulus presented an idiosyncratic variety in which the position is 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, i.e. multiplying by either the more common 12 or the 13 as used by Paulus, then projecting from the beginning of the sign (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 still it seems that among the Hellenistic astrologers it was only Paulus that preferred them, as at least 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 very skeptical about the use of the twelfth-part positions as representing a very important and informative additional chart that complements and integrates with the natal chart.  I’m sure many readers will 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, and 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 really used just like natal positions, giving additional information and revealing combinations and significations that might be missed from looking at the natal chart alone.  The interpretation of cognition usage that I discussed in the last post is along these lines too, even though it is for horary or consultation charts.  Masha’allah (in On Hidden Things) discussed multiple signficators for the querent’s thoughts or intentions, and one of them was the ruler of the Ascendant.  Masha’allah expressed that the best significator is the twelfth-part of the Ascendant and its ruler.  In other words, just as the Ascendant and its ruler give information about the character of the person or matter itself, the twelfth-part Ascendant and its ruler do too.

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 when he noted that the twelfth-parts of benefics occurring in important places (Sun, Moon, Mercury, 1st, 10th, 7th, 4th, Fortune, Spirit, Necessity, prenatal syzygy) signify very good things for the person, while the twelfth-parts of malefics occuring in such places indicates quite bad things. Benefics produce fortunate circumstances where they occur, and malefics produce difficulty, and it is such with the twelfth-parts of each as well.

Maternus laid out some instruction in use of twelfth-parts in Book II of the Mathesis.  There he instructed us to look at numerous things with particular stress on the place, the ruler, and the bound ruler of the twelfth-part, as well as interactions between planets of different sects that he discussed elsewhere, such as the greater harmony that the waxing and full moon has with diurnal planets as opposed to nocturnal.  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 be sure to look at the twelfth-part of the planet too, apparently to look at the same factors discussed with reference to the natal planet, so as not to 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 gave the same type of admonishment about checking the twelfth-part of the Lot of Fortune in Book IV, Ch. 4, after discussing how to delineate Fortune.  Again, the clear lesson is to delineate the twelfth-part as you’d delineate the planet.

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, but some delineations 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.

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.

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, and 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, are all additional indications of the strength of Mercury.  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, that 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)

The twelfth-part of Venus, the sect benefic, occupying Virgo, a house of Mercury, further emphasizes this fortunate quality of Mercury that could be easily missed from the natal chart alone.  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, and the twelfth-part Moon is strongly advancing toward the MC while 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.  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 that would be easy to miss from the natal chart alone, and give many additional indications that the chart is of someone with a high stature and great social mobility.

I will be returning to more past analyses with twelfth-parts in future posts.



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.