I was recently talking about twelfth-parts with a fellow astrologer so I decided to do a post, as this is one of my favourite sub-techniques that gives some subtle but meaningful information.
The twelfth-parts are a way of dividing up each 30-degree zodiac sign into 12 equal segments of 2.5 degrees each, with each part being ruled by a different sign. It’s a type of subdivision similar to decans/faces and bounds, in that the sign is broken down into smaller portions that have different rulerships.
I first learned about twelfth-parts when I was studying at Kepler, though the teacher referred to them as dwadasamsas. This is a term from Jyotish (Vedic or Indian astrology) and is often shortened to dwad (sometimes spelled duad). The Greeks called this subdivision the dodekatemoria.
It was actually only in the last couple days, as I was working on this post, that I realized dwads are the same thing as twelfth-parts – and that I much prefer using the Hellenistic term instead of the Jyotish term since I’m not a Vedic astrologer.
Twelfth-parts/dwadasamsas/dodekatemoria are a very old technique dating back to at least Mesopotamia. In each sign, the first twelfth-part is ruled by that same sign, and the rest of the parts proceed in zodiacal order from there. In this way, each sign contains a microcosm of the entire zodiac. As above, so below.
Here’s a handy reference table showing the twelfth-parts for each sign:
In Western astrology, twelfth-parts are used mainly to give additional meaning to the interpretation of an angle or planet in natal astrology – especially the Ascendant degree. You can think of the twelfth-part as a subtle colouring of that particular sign; an extra infusion of nuance to its main associations. A twelfth-part will never override the main significations of the overall sign, but it can add some extra distinction and complexity.
For example, my Ascendant is at 22°23’ Taurus. That means my Ascendant is in the Capricorn twelfth-part of Taurus. So, I’ve got a little Capricorn flavour to my Ascendant. Taurus is always going to be most prominent, but I’ve got a Capricorn vibe underneath all that bull energy. This describes me fairly well – both Capricorn and Taurus are earth signs, so this makes me extra earthy (yep), and it also infuses my Venusian Ascendant with some Saturnian sternness and responsibility. I love to indulge in good food and wine (very Taurus!) but it’s also important for me to maintain a steady day job in order to finance my indulgences (very Capricorn!).
You should also consider the ruling planet of the twelfth-part and how it operates within the chart as well as where it is located, for additional clues into how it might influence that angle/planet.
For example, Capricorn is my ninth house so it’s trine my Ascendant, and I’ve got Jupiter and my Midheaven degree there. So, that suggests ninth house topics like higher education and spirituality are important to my sense of self, and there’s a sense of abundance and fertility in these areas thanks to Jupiter’s presence in Capricorn natally, and the smooth-flowing trine aspect – and indeed that all tracks very nicely for me.
Twelfth-parts aren’t the first thing I will go to in a chart (or even the second or third). Once I’m really familiar with a chart, however, it’s fun to look up a list of the twelfth-parts for each planet/angle and see if there are any repetitions or other interesting patterns.
I have found that twelfth-parts can also help explain some of the more idiosyncratic expressions of a particular sign. My husband is a Virgo rising, but his Ascendant degree is in the Sagittarius twelfth-part of Virgo, which helps explain why he doesn’t quite fit the typically Virgoan characteristics.
And as we were workshopping his comic about twelfth-parts, he literally came up with this – Virgo-Sagittarius – as an example of a weird twelfth-part combo without realizing that this was literally him.
I also like using twelfth-parts with twin charts. Because twelfth-parts span only 2.5 degrees, and because the Ascendant degree moves so fast (about one degree every four minutes), even twins who are born only a few minutes apart will usually have Ascendant degrees in different twelfth-parts. This can give some better nuance to charts that are almost totally the same otherwise.
I also find it a useful exercise to think of the planets in signs in a slightly different way, and it helps explain why there are so many different ways that a particular sign can be expressed (all the other chart factors notwithstanding). What does it mean to have a Scorpio-Gemini Ascendant, versus a Scorpio-Aquarius Ascendant? How about a Leo-Libra Sun, or an Aries-Pisces Moon?
I have also used twelfth-parts in rectification work as one of my final checks, once I have the birth time pinned down to a narrow range. Because the twelfth-part of the Ascendant can provide some additional insight into the nature of the person, once I’m reasonably sure of a person’s rising sign, I’ll use twelfth-parts to double check the exact degree position.
Finally, I want to note that in Jyotish, dwadasamsas relate to the parents and are one of a number of different subdivisions used in that tradition. I can’t speak to the difference between interpretation of dwadasamsas and twelfth-parts as I know very little about Vedic astrology. However, the technique seems to be used quite differently between the different traditions.
So, there you have it: twelfth-parts are the same thing as dwadasamsas. Who knew? (Not me, until yesterday – much to my chagrin.)
If you’re curious to learn more about how twelfth-parts work in your chart, book a consultation with me.
Join me on Sunday, July 16, 2023 for a presentation on Twins and Twelfth Parts that I’m doing for OPA.