johannes susato wrote:do you - ore anyone else - know more authorities of that time, who followed Placidus or rejected his house-system? And why?

Here is the quotat?on I mentioned above, but it is not the English version. Ralph William Holden, The Elements of House Division, 1977. Under 'The Placidus System' he wonders that the Placisdus system is nowadays so popular and certainly the most spread method, whereas it was condemned by so many authorities at the beginning.

I am no expert on this period, but there were several English followers of the Placidus system towards the end of the 17th century. In 1687, Richard Kirby and John Bishop published The Marrow of Astrology, an unacknowledged and somewhat abbreviated translation of Placidus?s own work with very little original content added. The book was reissued only a year later, this time under the sole name of John Bishop and with a preface by William Lilly's pupil and adopted son Henry Coley, who mentions ?Dr. Wright, Thomas Moor Esq. Mr. Worral and [?] Mr. John Partridge? as other contemporary English adherents of Placidus, and feels that their endeavours ?ought to be encouraged, and assisted, as Aiming at Truth it self, and not rejected and rediculed, (as some are too forward to do)?.

It is perhaps not surprising that many of Placidus's contemporaries rejected his teachings, which were not confined to a (rather cumbersome) method of house division, but included a number of more or less radical innovations, several of which he attempted to foist off on Ptolemy.

...who followed Placidus or rejected his house-system? And why?

I don't know who followed the system but I can imagine some reasons why it would have been rejected in the early days. Somewhere here I read that the Roman Catholic church forbade Placidus' books in 1687. In R?diger Plantiko?s article (p.30) http://www.astrotexte.ch/sources/others/houses.pdf this is mentioned too and that it came up in Great Britain some 100 years later. It is often said that the popularity of Placidus is because of the availability of tables, I believe from Raphael since the early 1800's.

When you look at the figures 12 and 13 in that article (p.27/28 ) and compare it with the figures of the other house systems it becomes clear that Placidus doesn't use position circles. The lines are 'curves' instead of circles. One of the reasons that Plantiko gives why it took so long till Placidus was used was due to this fact (p.34 point 3). The perfect ideal in rationalist thought was the circle.

I don't agree with Plantiko relating Kepler's thoughts with the Placidus system (based upon the fact that Kepler had found out that the planetary orbits are ellipses). In a French translation of Mysterium Cosmographicum it is said that Kepler viewed the human soul either as circular or as a point, thus maintaining the ideal of the circle in this field. Notwithstanding the simplicity yet intelligence of the system, for me too the "rational ideal" is one of my main objections against Placidus.

Then if you must have great circles, use Svarogich's alternate formulation of the underlying Placidus model (http://www.levante.org) (which differs only slightly until you get towards extreme latitudes, and handles points that do not rise or set somewhat differently than Mike Wackford proposes for Placidus). The main difference from other great circle based systems is that it better reflects actual ascensional motion because the great circles defining mundane positions vary as to where they intersect the horizon, rather than all originating in a single pair of points as does, for example, Regiomontanus with its position circles at the north and south points of the horizon.

I still suspect that Placidus is the real thing, though.

- Ed

Hi Ed,

Until now I have failed to grasp the mathematics of Svarogich's system entirely. I find it too difficult to reconstruct and fully understand his system. This really annoys me, I mathematically understand and can construct every house system that exists (apart from Topocentric, I don't get that one either).

Concerning Michael Wackford's solution based upon Otto Ludwig's method for circumpolar objects, I don't feel comfortable with that. It simply doesn't fit in my ideal of circles and spheres. The issue called by Svarogich the "triple covering of the sphere" (footnote 24 of ?2) rather affirms my uneasy feelings towards Placidus(like) systems.

I'm sorry, I respect the (variants of) Placidus, but I simpy can't get accustomed to it. Maybe I'm a sort of Platonic conservative in my ideas of spheres.

It all depends, I think, on what you beleive you're doing with a "house" system or better named, a system of domification. Over the years, I've come to believe that a domification system is about describing the ascensional characteristics of points on the celestial sphere. Placidus and its derivatives do this most accurately and consistently, despite not completely adhering to our ideals about geometry.

Now just because that domification family does provide a largely accurate descriptive apparatus, that doesn't mean that other "house" systems are incorrect, just that they're not as good at descibing ascensional characteristics.

Then the question arises as to how important those characteristics are. To me, for primary directions and related methods, an accurate description of ascension is fundamental.

For topical house interpretation, perhaps it's not so important - after all, I find whole sign and various equal house methods generated out of sensitive points on the ecliptic to be useful for this kind of application, providing various complementary perspectives.

Guess it's a matter of what tools you choose to use, and how well-designed they are for the task at hand.

- Ed

Over the years, I've come to believe that a domification system is about describing the ascensional characteristics of points on the celestial sphere. Placidus and its derivatives do this most accurately and consistently, despite not completely adhering to our ideals about geometry.

Placidus indeed incorporates the ascensional chariacteristics in a good way. It combines equator with its parallels, meridian and horizon in one system. I acknowledge the shortcomings of the systems that I would prefer, Equal MC and Meridian system. These are not big problems to me because I give priority to other geometrical features. Moreover, since I feel for the ideas of Johannes Kepler, I consider the houses of lesser importance than the aspects, yet the different reference frames can also alter the aspects.

Equal MC (and Equal Ascendant) have as shortcomings that these are based upon the projections on the ecliptic. A planet with a certain (+/-) latitude that is conjunct the MC or Ascendant will usually not be in the meridian (or on the horizon). However, I consider the ecliptic as one of the most perfect frames of reference in astrology. The second perfect frame would be the equator I believe.

The Meridian equal houses variant would be another reasonable option. The ?Ascendant? of this system however, would be always the intersection point of the equator with the horizon. The risings and settings of stars and planets can occur in the houses X ? III and IV ? IX respectively. Although this is not according to the spirit of most house systems, I can accept it. I even believe this as according the most to our perception of nature. The drawback of course is that it is difficult to express the position of a planet in its diurnal/nocturnal arc towards its rising and setting point. These are namely usually not 180? apart. From here it?s a small step to Placidus but a too giant leap for me.

One of the reasons I consider the ecliptic more perfect than the equator is that the ecliptic rotates in 26.000 years and the equator in 24 sidereal hours. This makes me sometimes doubt if the equator should be used for transits (and secondary progressions), for which this plane should be ?fixed? to the ?slower? ecliptic which seems to make the equator ?subordinate? to the ecliptic. Yet for primary directions I consider the equatorial plane a good option.

I wonder which reference frame Kepler used for primary directions. I believe he used Regiomontanus in the cases he used houses but did he use these for primary directions too?

Eddy wrote:...
I wonder which reference frame Kepler used for primary directions. I believe he used Regiomontanus in the cases he used houses but did he use these for primary directions too?

I don't know the answer. It would be consistent.

- Ed

I don't know the answer. It would be consistent.

Absolutely. Unfortunately I didn?t manage to find anything on the internet about what system Kepler used for Primary Directions.

Eddy wrote:

I don't know the answer. It would be consistent.

Absolutely. Unfortunately I didn?t manage to find anything on the internet about what system Kepler used for Primary Directions.

He seems to have used his very own system, which was a precursor of solar arc directions rather than primary directions in the traditional sense. If you read German, you may be interested in a book on Kepler's techniques by Ulrike Voltmer, entitled Rhythmische Astrologie: Johannes Keplers Prognose-Methode aus neuer Sicht.

If you read German, you may be interested in a book on Kepler's techniques by Ulrike Voltmer.....

Last week I saw something about this book.
http://altairastrology.wordpress.com/20 ... ok-review/
However, in the list of Kepler's "criteria for judgement of the nativity (of Wallenstein)" compiled by Ulrike Voltmer, I read that Kepler used Placidus while the picture of Wallenstein's chart is clearly Regiomontanus. This made me doubt a bit about the book. Either the person who wrote the comment or Ulrike Voltmer made a mistake or Kepler himself was not really consistent. Unfortunately this is quite confusing.

Eddy wrote:Last week I saw something about this book.
http://altairastrology.wordpress.com/20 ... ok-review/
However, in the list of Kepler's "criteria for judgement of the nativity (of Wallenstein)" compiled by Ulrike Voltmer, I read that Kepler used Placidus while the picture of Wallenstein's chart is clearly Regiomontanus. This made me doubt a bit about the book. Either the person who wrote the comment or Ulrike Voltmer made a mistake or Kepler himself was not really consistent. Unfortunately this is quite confusing.

I would be very surprised indeed to learn that Kepler used Placidus houses. The Wallenstein chart, as you say, clearly has Regiomontanus cusps. I imagine the mistake is Voltmer's. In fact, I have had her book on my shelf for some time but haven't had the time to read it; and when I finally started on it a few days ago, I soon noticed that all the interesting bits seem to have been lifted out of a 1926 book (also in German) by a married couple (?) named Strauss. The rest is mainly Voltmer's personal philosophy of the limitations of astrology, for which she seeks the authority of Kepler, and highly dispensable.

Martin Gansten wrote:I imagine the mistake is Voltmer's.

That's what I start to believe too. The author of the article I mentioned in my last post (on the altairastrology website) seems acquainted with mathematics, so I don?t think it was he who would have made a mistake. It took me a while to find a review on Ulrike Voltmer?s book but here?s a review from R?diger Plantiko. In German. http://astrologix.de/buecher/butip_23.htm
The techniques of the book are explained briefly and I find them confusing. According to Plantiko, Voltmer states that Kepler used a solar arc type (applied to the Moon) but not in the 1day = 1year formula but applied to the first hours after birth. Here Plantiko rather follows Zoe Wassiliko-Serecki findings that Kepler must have used 1day=1year progressions. Voltmer calls the solar arc directed Moon the Lunar Phase direction and thinks that Kepler did this so that the Moon would keep the same phase towards the Sun. However I believe Kepler wouldn?t have done this because these solar arc directed lunar phases don?t occur in natural reality. As far as I have understood Kepler he preferred to stay as close as possible to natural phenomena. I find the translation of Kenneth Negus much more clearly on the progressions ? 9.7 http://cura.free.fr/docum/15kep-en.html This seems to be less artificial and more correct. Unfortunately Negus? article doesn?t mention anything on the techniques of primary directions, probably referred to in ?10.

The rest is mainly Voltmer's personal philosophy of the limitations of astrology, for which she seeks the authority of Kepler, and highly dispensable.

I'm afraid so. Perhaps Voltmer believed that the directions were done according to Placidus and may have followed the idea that Ptolemy used the semiarc method like Placidus. Plantiko doesn?t mention this and nowhere on the internet I could find out which house system Voltmer prefers but I assume it is Placidus. Furthermore I see that she is a rather modern astrologer: Jung, Karma, Quaoar (asteroid) etc, considering Kepler?s ideas in this modern concept. Not really my cup of tea.

In another article of Plantiko which I mentioned a few posts ago I find that he connects Kepler?s ideas to Placidus? method of division too easily. Kepler usually rejected the houses and I assume the only reason he would have used a house system (Regiomontanus) is because his clients would expect this. Kepler?s rejection of houses is not the real issue here but related to this is the method of directing planets in primary directions. I believe he would not have used a quadrant system but rather a simple system based upon the movement of the directed MC and Ascendant along the ecliptic for every 4 minutes per year. Yet here my personal preferences influence this view.

In fact, I have had her book on my shelf for some time but haven't had the time to read it;....

Sounds familiar, I have quite a few books on my shelf that still are waiting to be read
I'll have a look if I can find more info on this Strauss couple.