Skyscript Astrology Forum

Hello to you
I've read lots of great things in this forum and website. Thanks for providing all the good info.

I read the thread where Paul wanted to discuss if Valens used sidereal - which to me seems he did.

Paul, do you have some more material about other ancient astrologers using sidereal? I know it is a difficult subject because at that time the zodiacs coinceded, almost the same. But like you pointed out in the Valens thread, there is evidence in their texts that they are indeed referring to fixed stars in their texts.

Do you have some more material to read about this subject.

I am sure they did use sidereal and they did also use whole sign houses and sometimes Alcabitius (dividing each quadrant equally into three houses).

Hi lifestudent

Can you remind me of which thread you have in mind, the topic came up a couple of times. Also, would it not have been better to reply in the thread in which I asked the question?

As far as I know, the place where I'm at right now, is that Valens used a sidereal zodiac for measurement, but may not have been fully aware of the implications of precession, later for example using techniques (for rising times) that one might use with a tropical approach. This suggests to me a confusion about the two which makes it difficult to ascertain with confidence which Valens would have wanted to employ philosophically, though even then I would probably lean more to sidereal than tropical.

I am sure they did use sidereal and they did also use whole sign houses and sometimes Alcabitius (dividing each quadrant equally into three houses).

I'm not sure what you mean here as I don't have the context anymore from which this question arises. But if I was talking just of Valens, then I don't think Valens used Alcabitius.
Also, really, all the quadrant and faux-quadrant house systems divide each quadrant into three houses. Each house system can really be conceived of answering the question of how to divide each quadrant into three. Alcabitius, like other time related house systems, divides the time it takes for a degree of the ecliptic to move from one angle to the next, something which other time based house systems like Placidus do. The difference is in how they choose to divide that up. Other house systems like say Regiomontanus divide up the angles spatially, along some great circle like, say, the equator.

But really they all divide up the quadrants just in different ways.

I'm not sure if Valens used Alcabitius - the only house systems I associate with him are Whole, Equal and Porphyry. Porphyry is a kind of quadrant house, but kind of not really, it divides up the ecliptic between the angles into equal 3rds of the ecliptic.

Probably, and I can't remember exactly which conversation you are referring to, but probably I was wondering whether Valens was a DELIBERATE sidereal astrologer or DELIBERATE tropical astrologer, and, more probable than that, I was playing devil's advocate, pointing out that by measuring the ecliptic via fixed stars he was indeed sidereal, but that this doesn't mean he was sidereal DELIBERATELY, or rather it doesn't mean he was a philosophical siderealist by which I mean he believed that the 'influence' of the zodiac (whatever we might mean by that) was derived from the stars themselves, such that moving the stars moves the influence, or to put it another way, moving the stars moves the zodiac. However we can still say he was a sidereal astrologer in the sense that that he measures from the stars and not the equinoxes. But ultimately must conclude that this may not be in full knowledge of all its implications as he later uses a tropical based measurement later on as though not aware of the implications of this difference - whether because the two coincided or because he wasn't savvy enough on the mathematics, or because he wasn't aware of or didn't care about the implications of precession I don't think we can tell.

Lifestudent wrote:

Paul, do you have some more material about other ancient astrologers using sidereal? I know it is a difficult subject because at that time the zodiacs coinceded, almost the same. But like you pointed out in the Valens thread, there is evidence in their texts that they are indeed referring to fixed stars in their texts.

Do you have some more material to read about this subject?

Lifestudent, have you seen this link? (Alexander Jones on the Zodiac)

http://skyscript.co.uk/forums/viewtopic.php?t=7423

I can't find Nick Kellerstom's article on the zodiacs which I have in hard copy, but his zodiac graph is at the end of the referenced article here:

http://www.mindserpent.com/American_His ... _stars.htm

From the article:

"Studies of luni-solar and planetary longitudes mentioned in Late-Babylonian horoscopes and diaries have revealed that they are always measured from a fixed position with respect to the stars and are therefore based on a sidereal zodiac. The use of a sidereal zodiac was continued by most astrologers of the Hellenistic and Roman Period.

"The following diagram, based on the data in Kollerstrom (2001), plots the longitude offsets as found in Late Babylonian horoscopes (purple data points) and Greek horoscopes (blue data points) with respect to the tropical zodiac. The slope of the weighed least-squares fit through the data is equivalent with a longitude shift of one degree in 75.4 years. Around the year AD 307 the astrologers' sidereal zodiac coincided with the tropical zodiac." [The black horizontal line is the tropical zodiac.]

I found Nick Kollerstrom's online article, "The Star Zodiac of Antiquity." There is an interesting graph that compares the western sidereal value (Aldebaran and Antares at 15 degrees of Taurus/Scorpio) with the Spica at 30 degrees Virgo zodiac (today's Lahiri value). The Spica zodiac gives the closest correlation with actual placements of planets in ancient horoscopes.

http://www.astrozero.co.uk/astroscience ... iquity.pdf

The Arabs were late in adopting the tropical zodiac. In The Book of Aristotle (Persian Nativities, Volume 1 translated by Benjamin Dykes) Masha?allah (770-c815), who used the Sassanian sidereal Zij al-Shahriyar tables, makes clear his opinion of the tropical concept:

?...the Egyptian school dissented on the course of the stars, and the Lot of Fortune, and Cor Leonis [Regulus]...For instance, Ptolemy, concerning the length and breadth of the stars [longitude and latitude] puts it that there is an addition of one degree for [every] succeeding 100 years, all of which is plainly omitted in the Zij al-Shahriyar.?

Other sidereal tables of Indian origin existed alongside the Persian Zij al-Shahriyar tables. These alternate tables appear to have been used in Masha?allah?s On Reception as discussed here: http://skyscript.co.uk/forums/viewtopic.php?t=8545

We know that after Ptolemy?s Almagest, Tetrabiblos and other texts were translated, Arab astrologers began to calculate charts in the tropical zodiac. Often during the transition period the literature doesn?t make clear which zodiac was being used, and we have to refer to the actual computed charts for clarification.

In the Introduction to Astrology of the World II Benjamin Dykes discusses the differences between tropical calculation and the sidereal zodiac used by Masha?allah and Abu Ma?shar. Because it?s now well known that the early generations of Arab astrologers used sidereal tables in their work, and used most or all of the astrological concepts and techniques inherited from antiquity, I remain puzzled as to why today these techniques are applied in the tropical zodiac without question or further investigation. We know from Masha?allah?s statement in The Book of Aristotle that the Arabs were aware of what they called ?the Egyptian? zodiac, and rejected that zodiac for their own work.

In the west sidereal astrologers who align themselves with the Cyril Fagan school do not use classical concepts as Fagan believed them to be solely tropical from the date of their origin. Only recently with our new translations of Hellenistic and Persian texts do we understand that these early techniques were first applied in the sidereal zodiac.

Valens`description of signs suggests sideral zodiac too.He talks about the animal Leo,its body parts, not degrees

"Leo is masculine, the house of the sun, free, fiery, temperate, intellectual, kingly, stable, noble,
upward-trending, changeable, solid, governing, civic, imperious, irascible, Men born under this sign are
distinguished, noble, steady, just, haters of evil, independent, haters of flattery, beneficent, inflated with
their lofty thoughts. If the houseruler is at an angle or in aspect with benefics, then brilliant, glorious
individuals are born, tyrants and kings.
Leo is hot: the bright star in its breast <Regulus> is fiery and stifling. The parts are as follows: to 20?
it is stifling, causing diseases of animals in the zones and places subject to it. The right side is moveable,
fiery; the south part is wet; the lower parts are destructive to everything; the middle and the left are
temperate.
Leo has ? stars. According to the Sphaerica

Therese wrote:Because it?s now well known that the early generations of Arab astrologers used sidereal tables in their work, and used most or all of the astrological concepts and techniques inherited from antiquity, I remain puzzled as to why today these techniques are applied in the tropical zodiac without question or further investigation. We know from Masha?allah?s statement in The Book of Aristotle that the Arabs were aware of what they called ?the Egyptian? zodiac, and rejected that zodiac for their own work.

The Greeks also rejected the Egyptian zodiac, as explained by Geminos. I just noticed this post and co-incidentally that happened after I made a Facebook post today, which brought up the issue of why the Arabs are thought to use a sidereal zodiac when so much emphasis in their work goes to the use of the Vernal Equinox as the point where the zodiac and numerous other cycles are begun and ended. I have very little time, so will just copy over the post I placed which appears in Chris Brennan's Facebook stream:

"In response to Ant's comment, I think many modern astrologers can easily get confused over the issues he brings attention to, because it is difficult for us to not assume that astronomer/astrologers of that era simply relied on available tables. But the astronomers were responsible for the creation of those tables, and many took their own measurments by using astrolabes, quadrants, etc, measuring the movement of planets by reference to the fixed stars. There seems no doubt that the theoretical expectation was to be using the principles of the tropical zodiac, but to do this they were reliant on using some form of sidereal reference. They wanted to start the zodiac from the vernal equinox, but to know where the vernal equinox was, they used sidereal systems, such as placing it in oppostiion to Spica or (popular for a while) with the star Zeta Piscium in Pisces. This makes it look like they were using a sidereal zodiac because they were using a sidereal frame of reference, but they sought to adhere to the principles of the tropical zodiac and have it commence from the vernal equinox, so it is not a straightforward issue - they were not "sidereal astrologers" according to the modern expectance of that phrase (neither, in fact, were the Babylonians, who developed the zodiac with the clear intention of it being quartered by the equinoxes and solstices)."

Additionally, I should probably add here that no modern astrologer can fully relate to the historical position, and it is probably wrong to try to place it in one camp or another. Anciently, there was close correspondence between the two systems - it wasn't until later that astrologers had to choose to depart with the principles of the tropical zodiac, if they were choosing to define themselves as "siderealists". To begin with there was just "the zodiac", which allowed mathematical division of the ecliptic in a way that was intrinsically connected to the Sun's annual cycle and its definition of the calendrical year.

Hi Deb

Thi link by astroart seems to suggest they actually used sideral zodiac.It`s a coronation

http://skyscript.co.uk/forums/viewtopic.php?t=8545

I think you missed the point of my post, which was not to deny that if we want to recreate historical charts we will usually get better results by using one of the sidereal frames of reference. My point was that it is wrong to deduce simplistic assumptions, and project upon ancient and early medieval sources a desire to be defined as "tropicalists" or "siderealists". They did not face that dilemma - their dilemma was being able to measure planetary movement in the zodiac accurately.

Deb wrote:There seems no doubt that the theoretical expectation was to be using the principles of the tropical zodiac, but to do this they were reliant on using some form of sidereal reference. They wanted to start the zodiac from the vernal equinox, but to know where the vernal equinox was, they used sidereal systems, such as placing it in oppostiion to Spica or (popular for a while) with the star Zeta Piscium in Pisces.

I really don't think that is true. The Babylonians who explicitly placed the equinox at 8? or 10? Aries obviously didn't want to start the zodiac from it (they defined it as starting 45? prior to Aldebaran). They may have believed the equinox to be fixed there, but that's a very different thing.

Yes, that is a significant point to make. It seems more and more that all evidence points to the vernal point being originally placed in the centre of the zodiac signs, since the oldest sources refer to it being placed in the 15th degree, and the antiscia relationships and references such as Virgo spanning two seasons make sense of this too. But definitely there was a schematic desire to have the zodiac quartered by the equinoxes and solstices - the identification of which was the first necessary step in the development of the zodiac, and to have Aries represent its starting point because of the association with the vernal point at that time.

Deb wrote:Yes, that is a significant point to make. It seems more and more that all evidence points to the vernal point being originally placed in the centre of the zodiac signs, since the oldest sources refer to it being placed in the 15th degree, and the antiscia relationships and references such as Virgo spanning two seasons make sense of this too. But definitely there was a schematic desire to have the zodiac quartered by the equinoxes and solstices - the identification of which was the first necessary step in the development of the zodiac, and to have Aries represent its starting point because of the association with the vernal point at that time.

That`s what they do in Asia. Their seasons and signs start at 15 of our signs. But they determined that the 15 of fixed signs are the start of seasons/year rather than the cardines