Skyscript Astrology Forum

In another thread, Misho wrote:

I'm a bit reluctant to use PDs from the Asc since birthtimes are rarely accurate to the minute. [...]

Directing the ascendant is probably the earliest form of direction there is (reflected in the fact that rising times were often used as a general template for directions). It is true that directions of the angles are very time-sensitive; the corresponding advantage is that they can be used in rectification if you know what you are doing.

For instance, I recall a particularly tricky rectification a couple of years ago that was eventually nailed down by two sets of directions, both involving the ascendant, a certain number of years apart. The first was its direction to the squares of the Moon and Mars (closely conjunct in the radix), which I said was likely to have corresponded to danger from water and/or to troubles for/with the mother or other important females in the native's life, and also to some major injury, serious inflammatory disease or the like. The second was the near-simultaneous direction of the ascendant to the square of Mercury and the trine of Venus, the former being likely to involve legal or business trouble, and the latter a major romantic relationship.

As it turned out, the native had in fact rescued his mother and another woman from drowning in the sea when he was 17 or 18 years old, and shortly afterwards suffered a serious back injury that was to affect him for many years to come; and when the birth time was adjusted to make that direction fall at the right time, the other directions also agreed in time with a period in his early thirties when he embarked on a new relationship while simultaneously having to assist his ex-wife who was facing legal action relating to fraud.

Directing the ascendant is probably the earliest form of direction there is (reflected in the fact that rising times were often used as a general template for directions). It is true that directions of the angles are very time-sensitive; the corresponding advantage is that they can be used in rectification if you know what you are doing.

Yes, this is the main advantage to see if the chart needs to be rectified.
A couple of events can confirm the validity of a birth time. Even a sextile can show up as important.
One tool that can be helpful is a listing of sensitive points that you can customize in most softwares. This can give you an idea of the sequence of aspects in a birth chart so that you can see the past and upcoming aspects when looking for specific PD activations.
Clockwise is Direct. Anti-clockwise is Converse

Martin Gansten wrote: Sun Apr 27, 2025 11:32 pmDirecting the ascendant is probably the earliest form of direction there is (reflected in the fact that rising times were often used as a general template for directions). It is true that directions of the angles are very time-sensitive; the corresponding advantage is that they can be used in rectification if you know what you are doing.

Hello Martin,
Your example raises all kinds of questions for me. Is it your observation that ancient astrologers used this technique you outline here? Modelling directions on the ecliptic like this is almost the same as the Van Dam method and I always thought that this was a very modern and rather idiosyncratic method.
Didn't the ancient astrologers use the rising times in an attempt to approach something along the lines of the semi-arc method?

I guess my question is: how old is the idea that you can do primary directions on the ecliptic?

Ruud66 wrote: Mon Apr 28, 2025 12:26 pm I guess my question is: how old is the idea that you can do primary directions on the ecliptic?

I'm not at all sure what you mean here, so please feel free to elaborate. I don't calculate directions by ecliptical longitude, but rather in the classical Ptolemaic manner (so that the ascendant is directed by oblique ascension). But the promissor is most commonly a point on the ecliptic, such as an aspect point. This was the standard method of directing throughout the ancient and medieval periods, and well into the modern.

Very interesting. So if I understand you correctly, there are two distinct ways of doing PD's.
1. If you direct the Ascendant like you describe, you actually direct the equator and everything you find there (like the Eastpoint /equatorial Ascendant) and then project everything back unto the ecliptic. For the Ascendant, the easiest way of doing that would be indeed using oblique ascension. I don’t see another way of visualising this, because modelling the primary motion directly on the ecliptic doesn’t make sense. After all, the ecliptic is the reference circle for the secondary motion, not the primary one.
2. If your direct the planets in the way you describe, then you take the ecliptic positions of the planets and their aspect points and project those onto the equator by semi-arc. Then you look for contacts on the equator.

This was my question: if you do the same with the planets as you say you do with the Ascendant, then you also have to project PD-positions back onto the ecliptic again. And this is something that was invented by Van Dam in the last century and it is therefore not an ancient approach. This doesn’t add up in my mind. Are there things I missed or misunderstood?

Ruud66 wrote: Thu May 01, 2025 6:46 am Very interesting. So if I understand you correctly, there are two distinct ways of doing PD's. [...]

Only since the 17th century, when Placidus invented his mundane aspects (etc.), and even Placidus kept the zodiacal aspects; he just added elements to the traditional model.

I think the problem lies in how you are visualizing this. If you look at this animation feature (linked to by PhoenixNoodleSoup on another thread not long ago), you can see the primary motion of the ecliptic (the white circle), including, of course, the longitudes (projections) of all the planets, their aspect points, etc. This is what Ptolemy and all the medieval authors following him describe. Everything moves towards the (eastern) horizon by oblique ascension and towards the meridian by right ascension; and if we want to direct a place somewhere between the two, we use a sliding scale (mixed ascensions = proportional semi-arcs).

I had some contact with Wim van Dam many years ago, but I can't say I ever looked into his methodology, so I assure you it hasn't influenced me. As for 'projecting PD-positions back onto the ecliptic', it's not really a matter of projecting as such, or of jumping back and forth between reference systems: they are already interconnected all the time.

Let's say you were born with the Sun exactly 2/3 of the way between rising and culminating (= on the 11th Placidus cusp). At any time after your birth, some point or other of the ecliptic will occupy the same relative position (2/3 towards culminating), and that point will be the directed ecliptical/zodiacal position of the Sun. This is whole idea behind the ancient practice of directing a significator through the terms, as a continuous motion, rather than isolated 'hits' whenever it comes across a promissor in the form of another planet, aspect point, fixed star or whatever. It is also the idea referred to by Stephanus the Philosopher (8th century?) when he writes:

And we, persevering in constant trials, find that the same transits contribute greatly to the outcomes of the periods, not only when the stars arrive in the places having authority over the fixing [= the natal positions], but also in the place of the times found from the circumambulation [= the directed positions].