Primary Directions before Ptolemy
Written by Administrator   
Tuesday, 23 February 2010

The Primary Directions before Ptolemy were practiced by OBLIQUE ASCENSION   ONLY.

This ancient method was called by some ARAB astrologers also 'the method of HERMES'.

The Directional Arc between Promissor and Significator here is EQUAL to the DIFFERENCE  IN TIME between their  RISE on the Eastern HORIZON ! 

Suppose we want to compute the primary directions by 'the method of Hermes' between the SUN and Venus.

We compute the times when both planets rose on the horizon of the birth.

 The difference in time shows the directional arc.

[ This is the so called 'dynamic' PD acc. to Hermes when we look at the actual rise of the planets on the day of birth.  This is easier to explain.]

In history though, these directions were computed by the ancient Greek astrologers very roughly with the rising times of the signs.


Who was the first to talk about the PRIMARY DIRECTIONS ?

SO far I came to Thrasyllus (42 BC - 37 AD) with a firm textual evidence.

The evidence is found in Porphyry's 'Introduction to Ptolemy'.
CCAG (Catalogus COdicum Astrologorum Graecorum) volume 5 part 4, page 203
In the chapter titled 'Peri aktinobolias' (Concerning the aspects).
Aktino-bolias = rays-throwing
Here Porphyry defines the ray-casting (aktinobolias) as an aspect by a planet thrown in the direction of the 24-hour rotation id est against the order of the zodiac signs.
Planet in Aries, he says, throws rays (of square) to Capricorn.
Porphyry further describes the system of PD of Thrasyllos.
He directed aspects (and planets) to the ascendant and also to the house-ruler of the Moon in some special cases!
We can infer that he directed also to the Moon.
Most probably by oblique ascensions.

But my question about
:arrow: WHO WAS the FIRST to talk about Primary Directions remains.

In Babylon they had tables with the rising times of the signs, I think counting on my memory only, in around 500 BC!
This was enough to do what did later Thrasyllos.


Porphyry actually described the system of Thrasyllus for calculatig the 'killig' direction.
In the sign of the ascendant Thrasyllus said that only rays-throwing squares and oppositions can kill (right aspects).
In the next sign, both, right and left squares and oppositions can kill.

(Squares and oppositions of whom ? He does not say. Probably of Mars and Saturn.)

Then he said that if the Moon is found in the sign where she happens to be together with the ruler of that sign or this ruler is in opposition to her, then the directions (aphesis) should be done through that ruler.
He gives example with the Moon in Saggitarius and Jupiter also there or in Gemini.
Then the aphesis should be done through Jupiter!
He does not say more, but
What he said implies that if this was not the case then the aphesis should be done through the Moon.

The circumambulation is, of course, nothing but Primary Directions of the ASC through the terms (bounds).
Alghebutar among the Arabs.


(Discussion from 2009  on the same topic is to be found in in Primary Directions Topic)



Porphyry also mentions about the rising times given by Hermes.

The rising times of the signs can be found in AKKADIAN texts and the earliest come from around 500 BC - 700 BC !

When-ever we find rising times of signs, then primary directions could be and most probably have been practiced.


Written in 2010, Feb.

Last Updated ( Tuesday, 09 March 2010 )