Posted: Fri Oct 19, 2018 2:54 pm
Mark, James, thank you! 
The different house systems seem to have begun flourishing in the ninth-century Arabic astrology, and I think this must be attributed to their willingness to improve astrology by adopting Ptolemaic views and utilizing more sophisticated mathematics. The partial shift to quadrant-based houses may well have started already in the fifth century, but the sources are too scanty to provide conclusive evidence.
Holden, for whatever reason, chose to translate only the texts that constitute or related to Book V of Epitome III (and also added some appendices for chapters from further texts). As the Rhetorius corpus, including Epitome III, has never been properly edited and published, Holden had to rely on the partial editions and therefore patchworked his translation from the partial editions of Epitomes II, III, and IIIb. I think a more comprehensive translation that reflects the real content and structure of the texts is badly needed.
Another problem is Holden's uncritical attribution of the text to Rhetorius, in which respect he follows Franz Cumont and Pingree, but modern readers had better not take this at face value.
There are five actual case horoscopes in the group of texts related to "Rhetorius". One of them is extant, among others, as Epitome III 6.52; this is Hor. nat. gr. 497.X.28, Eutocius's nativity, edited partially by Alessandro Olivieri in CCAG 1 and by Cumont in CCAG 4, and a partial translation is given in Neugebauer and van Hoesen's Greek Horoscopes under L497. It uses "Porphyrian" houses, but only in the chart, not in the text. This horoscope should also be edited and translated properly.
The second one is a certain stillborn baby's nativity, Hor. nat. gr. 482.III.21, found in Epitome IV 19. It is edited by Cumont in CCAG 8.1, and translated by Neugebauer and van Hoesen as L482. There is no indication of houses whatsoever.
All the rest of the horoscopes are from the unknown astrologer working for the Byzantine emperor Zeno:
(1) Hor. nat. gr. 440.IX.29 (the nativity of Pamprepius of Panopolis, an associate of Zeno's friend-turned-enemy, Illus). It is referenced in Epitome IIIa 89 (edited by Cumont in CCAG 8.3, untranslated) and found in Epitome III 5.113-117, which are edited by Cumont in CCAG 8.4 and translated by Holden as Chapters 113-117. It refers to a quadrant-based calculation, but the text does not reveal which.
(2) Hor. nat. gr. 463.IV.25 (the nativity of the son of the emperor Leo I, Zeno's father-in-law). It is possibly one of the imperial nativities referenced in Epitome IIIa 90, but cannot be found in Epitome III, only in Epitome IV 28<bis>. This is the nativity you allude to, but absolutely no reference to quadrant-based calculations is given. It is also very likely that the text is garbled, as most explanations are simply impossible.
(3) Hor. nat. gr. 428.IX.8 (perhaps the nativity of the emperor Zeno himself). It is found nowhere in Epitome III, only in Epitome IV 12, anonymously. It is edited by Cumont in CCAG 8.1, and translated by Holden in Appendix IV. It is a presentation how to calculate the places (houses) according to the "natural method" (phusikos logos), which is the "Alchabitius" method with the Ptolemaic five-degree offset.
This latter example would suggest that Zeno's astrologer used the modified "Alchabitius" method, and at least Pamprepius's horoscope should be understood in this way. There are, however, two pieces of evidence that this idea might be wrong:
(1) Zeno's (?) horoscope is extant in Arabic sources, in M??sh??ʾall??h's and Abū ʿAlī al-Khayy??ṭ's Books of nativities. M??sh??ʾall??h's work is extant only in Latin, and while Abū ʿAlī al-Khayy??ṭ's original Arabic is preserved, it has not been published, and the manuscripts are not available to me; therefore I need to rely on its Latin translation. (Both Latin translations were translated by Ben Dykes, although M??sh??ʾall??h's work only partially from the defective Paris manuscript.) Since this is the only nativity from Zeno's astrologer appearing in Arabic sources, one may assume it is for a notable person. The interpretations, which only appear in the Arabic, at least do not contradict to Zeno's fate, and therefore it might be his and may belong to the imperial horoscopes referred to in Epitome IIIa 90; it cannot be proven, though.
Now, in both Arabic sources whole-sign houses are used, which suggests they were used in the original version too. But how do we come to the modified "Alchabitius" houses then?
As it appears, Epitome III can be dated to 505 CE the earliest, according to the stellar longitudes in 5.58. However, Epitome IV, which preserves Zeno's (?) horoscope, refers to year 600 Diocletian, that is, 884 CE (Epitome IV 2), which is well within the age when Arabic astrology was flourishing, and therefore Epitome IV 12 (along with a couple of following chapters exhibiting the feats of advanced mathematical calculations) in its present form may well be a Byzantine astrologer's exercise.
In conclusion, while all three horoscopes were cast by Zeno's astrologer, one should be wary to conclude from the Greek version of Zeno's (?) horoscope in Epitome IV that he was using the modified "Alchabitius" method secondarily, and that's that.
(2) Apart from Epitome IV 12, the only alternative house system that appears in the "Rhetorius" corpus is the modified "Porphyry" method in Epitome III 5.46 (and in parallel sources). This chapter would be copied into the "Porphyry" manuscripts from here (appearing as "Porphyry" 52); that's why we invoke his name when referring to this method. (Curiously enough, Holden omitted the passages from his "Rhetorius" translation but not from his "Porphyry".) So it is easily conceivable that the degree-based calculation for the Pamprepius horoscope is modified "Porphyry", not modified "Alchabitius".
To sum up: it is far from granted that what we read as "Rhetorius" is simply Rhetorius as it is, period, and that the author should have used modified "Alchabitius" houses consistently. I am personally inclined to assume that Epitome IV was thoroughly reworked by a ninth-century Byzantine astrologer (just look at the pious formulas at the end of Epitome IV 12, atypical from Zeno's astrologer) and the modified "Alchabitius" calculations were devised by him; which also implies that, at least how I see it, only the modified "Porphyry" method was present in the fifth-century horoscopes, in Eutocius's horoscope and perhaps also in Pamprepius's.
The different house systems seem to have begun flourishing in the ninth-century Arabic astrology, and I think this must be attributed to their willingness to improve astrology by adopting Ptolemaic views and utilizing more sophisticated mathematics. The partial shift to quadrant-based houses may well have started already in the fifth century, but the sources are too scanty to provide conclusive evidence.
What you mean is the book edited and translated by James Holden, titled "Rhetorius the Egyptian, Astrological Compendium". An essential reading for the Rhetorius corpus is David Pingree's paper ("Antiochus and Rhetorius", Classical Philology 72.3 [1977]: 203-223), so I will refer to his naming conventions.TT wrote:If you have Rhetorius you can see he used both Alchabitius and whole signs,but at least in the case of the dead infant(page 164) ,alchabitius worked better
Holden, for whatever reason, chose to translate only the texts that constitute or related to Book V of Epitome III (and also added some appendices for chapters from further texts). As the Rhetorius corpus, including Epitome III, has never been properly edited and published, Holden had to rely on the partial editions and therefore patchworked his translation from the partial editions of Epitomes II, III, and IIIb. I think a more comprehensive translation that reflects the real content and structure of the texts is badly needed.
Another problem is Holden's uncritical attribution of the text to Rhetorius, in which respect he follows Franz Cumont and Pingree, but modern readers had better not take this at face value.
There are five actual case horoscopes in the group of texts related to "Rhetorius". One of them is extant, among others, as Epitome III 6.52; this is Hor. nat. gr. 497.X.28, Eutocius's nativity, edited partially by Alessandro Olivieri in CCAG 1 and by Cumont in CCAG 4, and a partial translation is given in Neugebauer and van Hoesen's Greek Horoscopes under L497. It uses "Porphyrian" houses, but only in the chart, not in the text. This horoscope should also be edited and translated properly.
The second one is a certain stillborn baby's nativity, Hor. nat. gr. 482.III.21, found in Epitome IV 19. It is edited by Cumont in CCAG 8.1, and translated by Neugebauer and van Hoesen as L482. There is no indication of houses whatsoever.
All the rest of the horoscopes are from the unknown astrologer working for the Byzantine emperor Zeno:
(1) Hor. nat. gr. 440.IX.29 (the nativity of Pamprepius of Panopolis, an associate of Zeno's friend-turned-enemy, Illus). It is referenced in Epitome IIIa 89 (edited by Cumont in CCAG 8.3, untranslated) and found in Epitome III 5.113-117, which are edited by Cumont in CCAG 8.4 and translated by Holden as Chapters 113-117. It refers to a quadrant-based calculation, but the text does not reveal which.
(2) Hor. nat. gr. 463.IV.25 (the nativity of the son of the emperor Leo I, Zeno's father-in-law). It is possibly one of the imperial nativities referenced in Epitome IIIa 90, but cannot be found in Epitome III, only in Epitome IV 28<bis>. This is the nativity you allude to, but absolutely no reference to quadrant-based calculations is given. It is also very likely that the text is garbled, as most explanations are simply impossible.
(3) Hor. nat. gr. 428.IX.8 (perhaps the nativity of the emperor Zeno himself). It is found nowhere in Epitome III, only in Epitome IV 12, anonymously. It is edited by Cumont in CCAG 8.1, and translated by Holden in Appendix IV. It is a presentation how to calculate the places (houses) according to the "natural method" (phusikos logos), which is the "Alchabitius" method with the Ptolemaic five-degree offset.
This latter example would suggest that Zeno's astrologer used the modified "Alchabitius" method, and at least Pamprepius's horoscope should be understood in this way. There are, however, two pieces of evidence that this idea might be wrong:
(1) Zeno's (?) horoscope is extant in Arabic sources, in M??sh??ʾall??h's and Abū ʿAlī al-Khayy??ṭ's Books of nativities. M??sh??ʾall??h's work is extant only in Latin, and while Abū ʿAlī al-Khayy??ṭ's original Arabic is preserved, it has not been published, and the manuscripts are not available to me; therefore I need to rely on its Latin translation. (Both Latin translations were translated by Ben Dykes, although M??sh??ʾall??h's work only partially from the defective Paris manuscript.) Since this is the only nativity from Zeno's astrologer appearing in Arabic sources, one may assume it is for a notable person. The interpretations, which only appear in the Arabic, at least do not contradict to Zeno's fate, and therefore it might be his and may belong to the imperial horoscopes referred to in Epitome IIIa 90; it cannot be proven, though.
Now, in both Arabic sources whole-sign houses are used, which suggests they were used in the original version too. But how do we come to the modified "Alchabitius" houses then?
As it appears, Epitome III can be dated to 505 CE the earliest, according to the stellar longitudes in 5.58. However, Epitome IV, which preserves Zeno's (?) horoscope, refers to year 600 Diocletian, that is, 884 CE (Epitome IV 2), which is well within the age when Arabic astrology was flourishing, and therefore Epitome IV 12 (along with a couple of following chapters exhibiting the feats of advanced mathematical calculations) in its present form may well be a Byzantine astrologer's exercise.
In conclusion, while all three horoscopes were cast by Zeno's astrologer, one should be wary to conclude from the Greek version of Zeno's (?) horoscope in Epitome IV that he was using the modified "Alchabitius" method secondarily, and that's that.
(2) Apart from Epitome IV 12, the only alternative house system that appears in the "Rhetorius" corpus is the modified "Porphyry" method in Epitome III 5.46 (and in parallel sources). This chapter would be copied into the "Porphyry" manuscripts from here (appearing as "Porphyry" 52); that's why we invoke his name when referring to this method. (Curiously enough, Holden omitted the passages from his "Rhetorius" translation but not from his "Porphyry".) So it is easily conceivable that the degree-based calculation for the Pamprepius horoscope is modified "Porphyry", not modified "Alchabitius".
To sum up: it is far from granted that what we read as "Rhetorius" is simply Rhetorius as it is, period, and that the author should have used modified "Alchabitius" houses consistently. I am personally inclined to assume that Epitome IV was thoroughly reworked by a ninth-century Byzantine astrologer (just look at the pious formulas at the end of Epitome IV 12, atypical from Zeno's astrologer) and the modified "Alchabitius" calculations were devised by him; which also implies that, at least how I see it, only the modified "Porphyry" method was present in the fifth-century horoscopes, in Eutocius's horoscope and perhaps also in Pamprepius's.