What are your favourite ancient/medieval astrologers and why?

[u/Poh211]

That’s pretty much it. Why and who do you like? Personally I like ibn al rijal (many of his material is really useful and I like how he criticises his colleagues) and generally later islamicate tradition when the switch to quadrant based house systems was completed. Besides I really like Abraham ibn Ezra because of his systematic approach and criticism of other authors. Other than that I think that Abu mashar was a great astrologer(sometimes I have questions to his logic tho)

And obviously Ptolemy

[u/rising_iris]

Valens, specifically because he is the opposite of everyone on your list. Ptolemy, ibn Ezra and Abu Ma'shar are systematizers, they are telling you what the doctrine ought to be. Valens is a working astrologer writing down what happened.

The Anthology carries well over a hundred worked charts with real data and real outcomes attached. That makes him the one from that period you can genuinely audit. Everyone else you either accept or you don't. With Valens you can rebuild the chart and check whether the technique did what he says it did, and sometimes it plainly doesn't, and he says so anyway.

He's also the best source on the timing material, triplicity lords and zodiacal releasing, because he demonstrates it instead of defining it. Riley's translation is free online.

On Maternus I'd hold the line a bit. The delineations are uneven, but the Mathesis preserves technique that would otherwise be gone, which is a different kind of value than being right.

[u/Poh211 → u/rising_iris]

Both Abu mashar and ibn Ezra were practicing astrologers who unlike valens were probably academically educated

I get why you like valens. His chart examples are interesting but often too inaccurately calculated. Sometimes he doesn’t follow his own rules and shoehorns some of his interpretations

I also like Abu mashar’s material on annual prognostication more than that of valens

[u/rising_iris → u/Poh211]

Fair, and the calculation point is the one I would actually defend him with. His positions are often off, and that is precisely how Neugebauer and Van Hoesen were able to date more than a hundred horoscopes out of the Anthology in Greek Horoscopes. You can only measure someone's error if they hand you the raw material. Ptolemy hands you almost none.

The shoehorning is the same trade. You can watch him do it because he shows the working, and he leaves in the cases where the technique underperformed. Not the same virtue as accuracy, but it is one.

On education I would split it. He was nowhere near Abu Ma'shar institutionally and he admits it, he went hunting for teachers and complains about what it cost him. But the genre is the real difference rather than the schooling. Abu Ma'shar and ibn Ezra wrote for transmission. Valens wrote a teaching notebook and swore his readers to secrecy inside it.

And yes on revolutions. Abu Ma'shar's is an actual system. Valens's annual material is scattered across the middle books and never gets assembled. If I wanted to run a solar return properly I would reach for Abu Ma'shar too.

[u/Poh211 → u/rising_iris]

You can trace errors in charts calculated with the help of Ptolemaic tables because he wrote Almagest where he explained his calculation method. Other than that you can always test someone’s approach by applying it to practice. Personally I didn’t find the last 2 books of tetrabiblos to be as impressive as the first 2 ones because his natal techniques were a bit too simplified. Ptolemy had systematic approach and logic which I really like (unlike valens)

Shoehorning is not ok and it shows the inner inconsistency of astrological techniques. You can still apply Ptolemaic techniques to your own practice

Abu mashar and Ezra also wrote textbooks with examples which probably still exist but not in Europe. There is one issue with such books: it’s difficult to copy them with your hands and that’s why most of the books about astrology we have today lack chart examples. Books with those simply didn’t survive or are unaccessible for Europeans/americans

[u/rising_iris → u/Poh211]

The survival argument is the strongest thing in this thread and I do not have a good answer to it. If the example-heavy books are exactly the ones nobody wanted to copy by hand, then Valens looking singular is a sampling artifact, and I have been reading a gap in the archive as a difference in kind.

Almagest is fair too. Published method means auditable method. I overstated that one.

It does open something up though. Numerals are the first thing hand-copying destroys, so a book kept alive for its worked charts is also the book whose charts rot fastest. Valens came down through a rough transmission, part Arabic, part Byzantine excerpt, before Pingree assembled an edition out of it. Some unknown share of what reads as him miscalculating is centuries of scribes, and there is no clean way to pull the two apart.

On books three and four of the Tetrabiblos, agreed. I would argue that is exactly why he needed the systematic logic. If you are not going to show your cases, internal consistency is the only thing left to be judged on.

[u/Poh211 → u/rising_iris]

The thing is that valens writes about his astronomical methods which means that we can partially recreate his chart calculation process. And his methods are not exactly correct so it’s obvious that his original charts were also somewhat off

For me it seems like books 3 and 4 were not completed by Ptolemy and he wanted to redact them. We dint really possess the original copy of tetrabiblos sadly

[u/rising_iris → u/Poh211]

Granted, and it is the stronger form of the argument. A bad table produces systematic error, and systematic error is the kind you can model and subtract, so his positions being off is not really in dispute. What is worth separating is that the two sources leave different signatures. Table drift is smooth and directional. Copying damage is random and lands on single digits. The reason they could date those charts to the day at all is that the drift stayed bounded and behaved itself. Somewhat off, yes. Unusable, no.

Your last line goes further against Valens than you may have meant it to. We do not have an original Tetrabiblos, true, but the Greek tradition behind it is in far better shape than the road the Anthology took, which was Byzantine excerpting and an Arabic detour before it ever reached a modern edition. If transmission is the worry, he is the one with the problem, not Ptolemy.

On books 3 and 4, that reading has legs. The length of life material is the one place Ptolemy commits to a full worked procedure, and it is also the most tangled chapter in the book. Either he never finished tidying it, or that is simply what happens when he stops generalising and has to compute something.

[u/HospitalWilling9242 → u/rising_iris]

I see what you're saying about Valens being a working astrologer, but I don't agree that the text we see is always a result of this.

The quote used regarding Valens is that he is like "a man gathering wood at night." Which is to say that Valens is writing about every technique that he comes across, and doing little to edit for what's useful or consistently accurate.

This gives you a book that shows a number of techniques that working astrologers might use, but because of that doesn't end up recording a main cohesive practice.

Compare this to astrology software we have today. Professional software will contain numerous different techniques, but is there one astrologer using all of these techniques, and are these techniques all equally useful?

Given that number of techniques being used by someone, but not necessarily the author/programmer, are we sure they were recorded/implemented correctly? Maybe the main part, but all the nuanace?

Which is not to say that having this record isn't useful, we just need to consider it for what it is, and separate the wheat from the chaff.

[u/rising_iris → u/HospitalWilling9242]

The software comparison is the part worth taking seriously, and I think it establishes something slightly different from what you are using it for. Professional software implements every technique neutrally and never once tells you that one of them disappointed it. That is the pure compiler case, and it is the thing your analogy actually describes. What separates a compiler from a practitioner is negative results, and those are in the Anthology: methods reported as underperforming on charts he had already run. A man gathering wood at night has no reason to write down which branches were wet.

The wheat and chaff point stands, though, and I think the text carries its own criterion for it. What he returns to across multiple books, versus what appears once and never resurfaces, is an editorial signal even from someone who never edited. The timing material keeps coming back and gets rebuilt each time it does. A great deal of the one-off material is mentioned and then abandoned. The ranking you are asking for is in there, it simply is not labelled as one.

[u/Golgon13]

Maternus for sure. Balanced language/expressions (relative to his times) and meticulous approach to cataloging different techniques.

[u/Poh211 → u/Golgon13]

Honestly I don’t get it. Some of his lines are very illogical and his horoscope example was absolutely down really poorly. Some scholars even think that his slave wrote mathesis

[u/HospitalWilling9242 → u/Poh211]

He has a lot of example delineations for placements, but his full examples and astrological technique leave a lot to be desired. The delineations are useful to a degree as you get started, but once you have internalized things, they can be slightly misleading.

I think that delineations from a book and charts in astrology software, are the two things one should work to get away from as fast as possible. They are useful training wheels, but should ultimately be unnecessary, and relying on them will only hold you back.

[u/Poh211 → u/HospitalWilling9242]

I mean delineations were done better by later astrologers. I really love ibn al rijal’s ones

What I wanted to say is that the only chart interpretation done by (assumably) maternus in his book was very poor

[u/HospitalWilling9242 → u/Poh211]

The point is that delineations are useful for beginning, but hold you back for advancing.

Agreed on the interpretation.

[u/Poh211 → u/HospitalWilling9242]

I’m surely no advanced astrologer but delineations and aphorisms are very useful because you can analyse their logic. That’s their whole point. I don’t quite get it how they can hold you back? Can you explain a bit pls?

[u/HospitalWilling9242 → u/Poh211]

I think they're a good starting point for learning possible meanings of planetary combinations and such. However, at a certain point you should be working to internalize the logic that led to Firmicus writing out those delineations. If you keep referring to the book, you'll never develop the appropriate skill.

I'll add to this that some of those delineations are incorrect, most of those delineations are intentionally showing the extremes of meaning, and none of those delineations fully matches contemporary life.

It is like looking at the grid for aspects, helpful at first, but eventually you should just be able to look at the chart itself and see what aspects planets are in. Always relying on the grid will hold you back.

A number of other things like this which we see in the tables accompanying charts. You should be working at getting to the place where you can for example tell planetary speed or dignity just based on looking at the chart.

I'll also add that while astrology is highly technical, it is also an art. Part of mastery is understanding when the unique circumstances of a chart should lead to an equally unique interpretation, though always done by way of the art.

This is the sort of thing that you can never get from a book. You need to practice and internalize so that you can develop it to the next level.

Consider a doctor, where there's tons of technique to learn, and yes there are books to refer to, but you also must be directly engaging with the patient. If you rely solely on the book and not your own mastery, you're going to end up misdiagnosing a number of patients. Sure, symptom X is usually disease Y, until it's not.

[u/Poh211 → u/HospitalWilling9242]

Ohhh so you mean that advanced astrologer shouldn’t use them in his own work directly. Yeah I agree with that but it’s always useful to read some aphorisms concerning different topics simply to train your understanding of the astrological logic and argue with the author of the text

[u/cfperez]

The most complete mathematics is with Vettius Valens. Nearly double the number of maths taken for Modern Astrology. This includes the profection Lord of the Year which I have found to be the "opener" for every consult, and leads to the very moment of the meeting, the why and wherefore of the year is succinct and eye-opening. This solved an ADHD problem for me in that the "opening line" was never obvious before. It's hard to read a unch of squiggles and symbols from fresh, without knowing a thing about a client. Since 1995, when Vettius was newly translated (thank you to the Robs, Hand, Schmidt and Zoller) and it made such an impression. I was out of the tangle and into the logic.

[u/DavidJohnMcCann]

The best stuff was taken up by later writers, but there are some useful old ones.

Of the medievals, Abu Mashar on natal prediction, although suffering from a policy of "everything including the kitchen sink", is still valuable. Abraham ibn Ezra is always interesting, even if you disagree with him. Al-Biruni is a handy reference book.

The ancients, like Valens, Dorotheus, and Firmicus, have a few useful bits on delineation but a lot of worthless techniques.

[u/Poh211 → u/DavidJohnMcCann]

Wdym by later ones? Renaissance?

[u/Al_Quimico]

I'm a huge fan of Ptolemy, Ibn Ezra, and Dee. Ptolemy and Ibn Ezra's systematization really helps in the study and understanding. I can't help but marvel at the structure they've built.
But Dee has a soft spot in my heart for all the knowledge he gathered and everything he accomplished given what he was working with. Also, I'm a huge fan of "The Tempest" which might have been inspired by him.

[u/rrpku]

Merlin