PDA

View Full Version : Tetrabiblos vs. An Introduction to Tetrabiblos


byjove
07-20-2011, 01:47 PM
Hi,

I didn't want to get into general house system debates and wanted to address these books specifically so...

1. What exactly are the differences between Porphyry's approach to natal vs. Ptolemy? I tried my chart with the Porphyry system and it produces seemingly identical results to Placidus. Does that change for time/latitude?

2. Did Porphyry suggest any improvements over Ptolemy's usage?

3. Why would Porphyry write an Introduction? To clarify, examine, explore etc.?

4. Any other comments, ideas, observations?

I've been exploring the translated Tetrabiblos and then came across Porphyry's Introduction and got curious. I thought that Ptolmey's Equal house was an alleged 'improvement' on the older Whole Sign? Also, was Whole Sign not said to be 'the original' system used? How come these Greek works bring up 3 systems; Whole Sign, Porphyry and Equal instead of one 'original'? But then Porphyry jumps to his named house system, which greatly resembles Placidus in my chart. I'm confused!

ILike2Paint
11-09-2013, 02:17 PM
Hello.
For question 1: I'm not sure of Ptolemy's approach to house divisions, but I've compared Placidus and Porphyry.

Porphyry is based entirely on the ecliptic, on space. Because it relies on the Midheaven (MC) and Ascendant (AC), it works for anywhere that the MC and AC are not the same.
Porphyry solves the problem of houses not working in northern latitudes.

I don't know why Placidus and Porphyry would produce similar houses because Placidus is calculated in a different way, based on time. For latitudes beyond about 66 degrees north or south, Placidus is undefined, so there is no way to compare them there.

byjove
11-09-2013, 04:49 PM
Hi, thanks for the feedback.

I was curious about Porphry and Placidus not typically producing similar houses, so I checked mine again and decided to post them here. It's strange! I don't think any of my natal planets changes houses either.

ILike2Paint
11-09-2013, 09:50 PM
I noticed after comparing the charts that your Saturn changes house (5th or 6th) but the other planets are in the same houses in each one.

dr. farr
11-10-2013, 03:53 AM
Actually the "Porphyry" system had been applied long prior to the time of Porphyry, but NOT for domification (ie not for erecting the houses of a chart) but rather for determining planetary strengths via angularity.

Robert Hand and others have challenged the commonly held belief that Claudius Ptolemy used (or introduced) Equal House (see for example Hand's observations in his "Whole Sign Houses" book)-others-such as Charles Carter (Modernist pioneer who used Equal House) also had serious doubts about Ptolemy's (alleged) introduction of that format (personally, after looking at various evidences including Hand's, I believe that Ptolemy and Firmicus Maternus both used whole sign house format for domicification)

Olympiodorus in the 500's is the first Hellenist author to refer to practitioners (some practitioners) of that time using the Porphyry format for domification (chart house erection)-he states that their reason for doing so was to put the MC/IC where they are SUPPOSED to be, ie, the MC at the beginning of the 10th house and the IC at the beginning of the 4th house (in whole sign and in Equal House formats the MC and IC can "float" between several houses)...so the Porphyry method ensured that the MC/IC axis would always accord in house placement with the meanings attributed to the 10th and 4th houses.

In the 10th century Sripati introduced what amounts to the Porphyry domification method to Indian astrology (which had exclusively used whole sign or Equal House formats prior to that time) The Sripati format (ie Porphyry format) has been extensively used for domification in mainstream (Parasara) Vedic astrology since then (although Equal House has remained very strong-only the minority Jaimini school of Vedic astrology continues to exclusively use the ancient whole sign format)...

waybread
11-10-2013, 03:53 AM
Ptolemy actually says very little about houses. He mentions only a few of them, and then he doesn't really talk about house cusps much. At one point he suggests using 5 degrees into a sign, but then this might be for the particular technique in question only.

Some traditional astrologers simply assume that Ptolemy used whole sign houses, but actually not much in Tetrabiblos requires any sort of house calculation, or discusses the thematic content of houses. I think Ptolemy tried to sidestep the issue as much as he could. My hunch is that this is because the house meanings were originally based upon the ancient Egyptian religion, and rationalist Ptolemy just couldn't fit them into his logical world view.

You do find houses in his contemporaries, but the absence of discussions of house system calculations leads Hellenistic astrologers to conclude that these must therefore have been whole-sign houses.

Porphyry is really a natural and very simple quadrant house system. Locate the AC/DC axis as the points of sunrise in the east and sunset in the west. Locate the highest point of the sun on its passage across the sky at mid-day, and there s your MC. The opposite point is your IC. You know have 4 quadrants, which you divide into equal thirds. You can actually go outside and eyeball this system, which is probably how it was originally developed.

The Babylonians didn't use houses, and based their astrology on the passage of the moon, not the sun; more like the Indian nakshatra system. So somebody subsequently, developed the idea of houses vs. just planets in signs.

waybread
11-10-2013, 04:02 AM
At very high latitudes any kind of house system will be troubled. With whole signs of equal houses, you can get nice, neat 30-degree pie sectors for houses; but you can actually get the MC in the 12th house. With a quadrant house system, the MC is still the 10th house cusp, but you can get a lot of skewing.

A lot depends upon the time of year you construct the house. In the far north, the sun appears to move well to the south in winter, and far to the north in summer. So the sun doesn't just "set in the west" in summer, but sets well into the northwest.

Porphyry can smooth out the bumps slightly, but if your MC is still seriously tilted, you will still get two small opposite quadrants with skinny houses, and two big opposite quadrants with wide houses.

With Porphyry, you can get intercepted signs, as with the other quadrant (unequal) house systems.

I've attatched the charts of a former prme minister of Finland to illustrate the problem.

dr. farr
11-10-2013, 04:05 AM
I used Placidus for decades (until my discovery of whole sign)-IF I had to choose any quadrant house system, my choice would be Placidus (because I obtained very good results with it for many years)...

JUPITERASC
11-10-2013, 08:55 AM
Actually the "Porphyry" system had been applied long prior to the time of Porphyry, but NOT for domification (ie not for erecting the houses of a chart) but rather for determining planetary strengths via angularity.

Robert Hand and others have challenged the commonly held belief that Claudius Ptolemy used (or introduced) Equal House (see for example Hand's observations in his "Whole Sign Houses" book)-others-such as Charles Carter (Modernist pioneer who used Equal House) also had serious doubts about Ptolemy's (alleged) introduction of that format (personally, after looking at various evidences including Hand's, I believe that Ptolemy and Firmicus Maternus both used whole sign house format for domicification)
Ptolemy was not a practicing astrologer

Olympiodorus in the 500's is the first Hellenist author to refer to practitioners (some practitioners) of that time using the Porphyry format for domification (chart house erection)-he states that their reason for doing so was to put the MC/IC where they are SUPPOSED to be, ie, the MC at the beginning of the 10th house and the IC at the beginning of the 4th house (in whole sign and in Equal House formats the MC and IC can "float" between several houses)...so the Porphyry method ensured that the MC/IC axis would always accord in house placement with the meanings attributed to the 10th and 4th houses.
LATE CLASSICAL ASTROLOGY
PAULUS ALEXANDRINUS AND OLYMPIODORUS :smile:
TRANSLATED BY DORIAN GREENBAUM - ARHAT
http://www.astroclassic.org/text-trad/PO%20a.pdf
In the 10th century Sripati introduced what amounts to the Porphyry domification method to Indian astrology (which had exclusively used whole sign or Equal House formats prior to that time) The Sripati format (ie Porphyry format) has been extensively used for domification in mainstream (Parasara) Vedic astrology since then (although Equal House has remained very strong-only the minority Jaimini school of Vedic astrology continues to exclusively use the ancient whole sign format)...

waybread
11-10-2013, 07:50 PM
We have no idea whether Ptolemy practiced or not, simply because he didn't refer to clients. His project was to rationalize astrology more in keeping with the Aristotelian "science" of his day. But either way, this is a big "so what?" given the extraordinary influence Ptolemy had on the practising astrologers who followed him and who relied upon his work.

JUPITERASC
11-10-2013, 09:42 PM
We have no idea whether Ptolemy practiced or not, simply because he didn't refer to clients. His project was to rationalize astrology more in keeping with the Aristotelian "science" of his day. But either way, this is a big "so what?" given the extraordinary influence Ptolemy had on the practising astrologers who followed him and who relied upon his work.
On the contrary :smile:

QUOTE

from Albert Timashev writing an article entitled "Reconstruction of The Major Egyptian Years"

"Today it is well known
that Greek scientist Claudius Ptolemy was not a representative of a traditional Greek astrological school
and, most likely, he was never a practicing astrologer at all.
Ptolemy's work Tetrabiblos reflects his personal and disputable opinions on many questions."


QUOTE from Professor Mark Riley, California State University

'….. Vettius Valens' Anthologiae is the longest extant astrological work from antiquity.

It is unique in several respects:
the author was a practicing astrologer:

the work includes more than 100 authentic horoscopes of Valens' clients or associates,
including his own, which is used as an example many times throughout the work
the work also includes tables and the description of algorithms used by astrologers and mathematicians.....'


Ptolemy built on the work of Apollonius of Perga who
- approximately four centuries earlier than Ptolemy -
developed a form of geometric particular methods within the geometrical practice, that are to do with circular motion
- as well as motions of circles moving on circles and so on -

that Ptolemy then applied to discovering the much sought-after geometrical rationale thought to be underlying appearances


Thus Ptolemy described a rationale that 'explained' retrograde motion - but incorrectly -

because the planets do not move with uniform circular motion in circles

In Almagest, written 2nd century AD, PTOLEMY PROPOSED THAT THE EARTH WAS AT THE CENTRE OF THE UNIVERSE


Ptolemy's incorrect, yet mathematically appealing, idea of the universe http://csep10.phys.utk.edu/astr161/l...aristotle.html (http://csep10.phys.utk.edu/astr161/lect/retrograde/aristotle.html)


Ptolemy's model of the universe remained the dominant one for over a thousand years. It was not until 1543, and Copernicus's heliocentric theory of the world, that the Ptolemaic model was finally challenged
and not until 1609 that Johannes Kepler's New Astronomy put an end to Ptolemy's ideas for good :smile:

byjove
11-10-2013, 11:32 PM
Oh Lordy, the 'who's a real/reputable astrologer' idea again. :pinched:

I set up the thread a long time ago, I can't even remember my reading trails at that time...:whistling: It was brought up recently by a reply. An Introduction to Tetrabiblos had some slight re-interpretations I think?

Equal houses - if the history of equal houses ... isn't as consistent as with some other house systems, how can one consider it in natal interpretation? On the other hand ... it hasn't been proven that it is definitely a matter of misinterpretation that equal houses came into being, has it? I really don't know where to put equal houses in the context of things, in my own mind.

I think the theory of the signs/planets is one way of resolving house dispute issues for the individual astrologer. He/She could figure out whether they have natal Jupiter in the 5th or 6th, 11th or 12th, or Mercury in the 4th or 5th etc. For me, the 'natal interpretation is far more complicated than quick interpretations like that' is a quick smoke and mirrors exit from the conversation. Confusion or detail won't confuse everyone.

The former Prime Minister of Finland - yep, those charts illustrate the problem perfectly.

JUPITERASC
11-10-2013, 11:57 PM
Oh Lordy, the 'who's a real/reputable astrologer' idea again. :pinched:
That's not the issue :smile:

It's simply important to be aware that,

to quote Professor Mark Riley of California State University:


QUOTE

'....Ptolemy's discussion is entirely theoretical – in this respect he is unique amongst ancient writers on astrology.

Ptolemy never mentions individuals, never cites horoscopes, never describes what an astrologer really does in his everyday business....'

waybread
11-11-2013, 01:36 AM
JA, I am aware of all of these opinions, but there is simply no direct evidence, either way. And it really is a big "so what." Ptolemy influenced many practicing astrologers who came after him, so you'd think that if his methods didn't stand up to the practical tests of chart-reading, his inheritors would have abandoned him centuries ago.

To the contrary....

greybeard
11-11-2013, 02:35 AM
Whole sign, equal, and Porphyry house systems are based solely on the ecliptic.
The quadrant systems (apart from Porphyry) all drag the equator into the melee.

If we want to (I don't) we can argue for/against the two basic divisions of house systems on philosophical grounds: what is the effect of referring a house system to the equator? Should we do that, and why?

The other basis (that I see) for arguing for/against any system is its practical application. Does it give reliable results? Which system yields the very best results?

I use Placidus. It works. IF I were to change, it would be to whole sign. But....I'm old, set in my ways, used to Placidus, confident in its use.

As Dr. Farr pointed out, the Porphyry system is rooted in the idea of "strength" rather than as a system of domification, and the basic idea persists (angular, succedent, cadent) today.

Each and every astrologer develops his/her own methodology and always imposes his/her own personality on the process of interpretation. We can't help that; we are unique individuals who think and feel in different ways. What is all this arguing about? It boils down to Belief, and God save me from that!

It doesn't really matter if Ptolemy was a practicing astrologer or the royal plumber. He left behind a valuable reference source, brought some order to the art, and instructed generations of astrologers. We can take from him what we find of value and leave the rest.

JUPITERASC
11-11-2013, 09:17 AM
JA, I am aware of all of these opinions, but there is simply no direct evidence, either way. And it really is a big "so what." Ptolemy influenced many practicing astrologers who came after him, so you'd think that if his methods didn't stand up to the practical tests of chart-reading, his inheritors would have abandoned him centuries ago.

To the contrary....
That of course is your opinion
Hi,

I didn't want to get into general house system debates and wanted to address these books specifically so...

1. What exactly are the differences between Porphyry's approach to natal vs. Ptolemy?
Interestingly, neither Ptolemy nor Porphyry were practicing astrologers

QUOTE

'.....Porphyry of Tyre was a prominent Neoplatonic philosopher who flourished in the late 3rd century CE.
Porphyry is primarily known as the student of the founder of Neoplatonism, Plotinus,
although he was regarded as an important philosopher in his own right in Late Antiquity.
Porphyry occasionally made references to astrological doctrines in his philosophical works,
and there is at least one surviving text on astrology that was attributed to him.....' source: Chris Brennan

Ptolemy did not write from the perspective of a practicing astrologer, never mentions individuals, never cites horoscopes, never describes what an astrologer really does in his everyday business. And that is important because it clearly shows the evidence that Ptolemy's approach was entirely theoretical - Ptolemy never applied astrological theory to the real world of natal chart delineation as experienced by a practicing astrologer

For example

Ptolemy's Table of Essential Dignities
although commonly in use is not espoused by all
many astrologers use the Egyptian Terms or the Chaldean Terms
because those are considered to provide more reliable results in practice
when compared with Ptolemy's Terms :smile:

QUOTE

'…..The Introduction to the Tetrabiblos - Porphyry is attributed authorship of an introduction to Ptolemy’s Tetrabiblos,
titled Introduction to the Apotelesmatika of Ptolemy (Εἰσαγωγὴ εἰς τὴν Ἀποτελεσματικὴν τοῦ Πτολεμαίου).

The Introduction mainly consists of a series of definitions of basic astrological concepts.

MOST OF THE DEFINITIONS WERE COPIED VERBATIM FROM A LOST WORK OF DEFINITIONS BY ANTIOCHUS OF ATHENS

The extant version of the Introduction appears to be incomplete, and it also contains a number of interpolations from a work by the 9th century astrologer Sahl ibn Bishr.....'
source: Chris Brennan


'…...“Porphyry” House Division

Holden points out that Porphyry is best known by astrologers in modern times for the system of quadrant house division that bears his name, the so-called “Porphyry House System,” which is outlined in chapter 43 of the Introduction (Holden, 1996, pg. 62).

However, Holden rightly points out that the same system was described about a century earlier by Vettius Valens (Anthology, 3, 3), and so it is only an accident of history that Porphyry’s name became associated with the system rather than that of Valens......' source: Chris Brennan


Alcabitius is best for assessing planetary strength.
Whole Sign for topical purposes