directions as mentioned by sahl bin bisher

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i just finished reading this book 'the introduction to the science of the judgments of the stars' sahl ibn bishr - james holden translation..

i am going to assume by the word 'direction' primary direction is implied, but i am not completely sure about this. this quote is found on page 188/189 of the above mentioned book.

"And from the direction of the degree of the ASC or of any of the Planets to any particular degree [is] a year, a month, and a day, or an hour; or back to any one of the Planets to its rays and them, and to the degrees of the signs and to the Parts is a time; and Mash'allah has already said this, and Abuabalgharat, i.e. The Tailor, have [both] said not to direct the degree in longitude and latitude forward or backward. Therefore, it is from the motions of the universal circle that the times that are made from these motions are known."

i find this paragraph particularly interesting, partly as i am unclear as to what exactly sahl ibn bishr is getting at and more..

my first impression is this is giving a quick overview on solar arc directions or secondary progressions, - 'a year'.. tertiary progressions - 'a month', transits - 'a day' and what for 'an hour' i don't know.

i believe "the motions of the universal circle" is in reference to the daily motion of the planets rising in the east and setting in the west and the times these signs/planets take to reach different points in the circle.. i think the motion of the planets thru the zodiac is in reference to longitude and latitude and the idea is to ''direct'' according to the one circle and not the other..

the "forward and backward" comment seems to be hitting on this distinction as well, although maybe i am mistaken and it is in reference to converse or direct motion..

it is hard to know and perhaps it is really just a dissertation on primary directions and what to do or not do when working with them...

thoughts anyone?

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If this is not a reference to Ptolemy's directions in the right circle (otherwise known as proportional semi-arc method), it might be one of the annual divisions of the circle based upon a proportion of the year. Ben Dykes asked me to program a variation on annual divisions based upon Umar al-Tabari's incremential profection method. I believe Umar had it fixed as a degree per day, but we experimented with using oblique ascensions as a proportion of the arcs between planets and their aspects. Another possibility would be to use a form of mixed ascensions (based upon the proportional semi arc method, but scaled to the length of the year) that would more closely mimic the motion in the right sphere.
Curtis Manwaring
Zoidiasoft Technologies, LLC

Re: directions as mentioned by sahl bin bisher

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james_m wrote:"[...] Mash'allah has already said this, and Abuabalgharat, i.e. The Tailor, have [both] said not to direct the degree in longitude and latitude forward or backward."
The 'not' is a mistake. Holden has interpreted the abbreviation .n. as non, but it should be enim 'indeed'.

Whatever Sahl is referring to, we can be fairly certain it wasn't solar arcs, secondaries or tertiaries, all of which made their appearance about 800 years after his lifetime.
https://astrology.martingansten.com/