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The Astrology Podcast

Ep. 313 Transcript: House Division Calculations in Astrology Explained

The Astrology Podcast

Transcript of Episode 313, titled:

House Division Calculations in Astrology Explained

With Chris Brennan and astrologer Luís Ribeiro

Episode originally released on July 31, 2021


Note: This is a transcript of a spoken word podcast. If possible, we encourage you to listen to the audio or video version, since they include inflections that may not translate well when written out. Our transcripts are created by human transcribers, and the text may contain errors and differences from the spoken audio. If you find any errors then please send them to us by email: theastrologypodcast@gmail.com

Transcribed by Mary Sharon

Transcription released August 10, 2021

Copyright © 2021 TheAstrologyPodcast.com

CHRIS BRENNAN: Hi, my name is Chris Brennan, and you’re listening to The Astrology Podcast. In this episode, I’m going to be talking with Luís Ribeiro about the mathematics and astronomy underlying the different forms of house division, as well as the use of the astrolabe as a mechanical device for doing astrology during the Medieval period. Hey Luís, welcome back to the show.

LUIS RIBEIRO: I’m glad to be here.

CB: Thank you. We’ve been talking about doing this episode for a couple of years now, and we almost did it last year and then the pandemic broke out and I got sick. So I’m really happy that we finally got it together and I think this is going to be a really interesting discussion that a lot of people have been looking forward to. Thanks for joining me today.

LR: Yeah. Well, it’s a pleasure.

CB: Yeah. For those that don’t know, I should first say the date. Today’s Tuesday, July 27th, 2021, starting at 5:08 PM in Denver, Colorado. This should be the 313th episode of the show. So, Luís is the author of one of my favorite and basically one of my highest recommended intro to astrology books, which is titled On the Heavenly Spheres: A Treatise on Traditional Astrology. He teaches and practices astrology through his website academyofastrology.eu and also has a YouTube channel where he interviews different academics who work on the history and transmission of astrology. You can find that, it’s called the Astra project and I’ll put a link to it in the description just below this video. If you want to check out that channel, I’d highly recommend subscribing to it. So we’re going to talk about kind of a complicated topic today, which is the celestial mechanics and mathematics underlying house division and house division, of course, which system of house division to use is one of the biggest issues in astrology that astrologers have wrestled with for a long time now, in terms of practically speaking how to divide the chart and different arguments for doing that. But instead of focusing on that debate, which I’ve done different episodes on before, we’re going to focus on this issue from a different perspective, which is more just explaining what is the mathematical rationale or the astronomical rationale underlying the different systems of house division so that each astrologer can understand these systems better and make a more informed choice about which one to go with? How long have you been working on this issue of understanding the astronomy or the mathematics underlying house division?

LR: Well, Chris for a long time now. Although I’m not a mathematical inclined person, but I always search to understand how things work, what is the astronomical structure behind the different house systems and the different calculations we do? So, although I started many, many years ago like everyone else using the Placidus and the tables of houses that were most common at the time were Placidus house system, I always seek to understand exactly how are constructed and how are calculated the different systems. And when I did my research on which system to choose or I tried to calculate them by hand to understand the trigonometry and the mathematics and try to, if I didn’t have a table, how would I make the calculation? That was there that I learned a lot, and this was late 90s, early 2000s that I did this research to know more thoroughly.

CB: That was around the time that you got into traditional astrology, I think as well. Right?

LR: Exactly. Exactly, and part of understanding this was also what made me choose which system to use as well.

CB:  Yeah. I think that’s really important and that’s kind of tied in with that movement that many astrologers have had to go back and look at the sources, which is to, you know, usually people when you first learn astrology kind of just default to whatever system or approach you first used. But for some of us that then went back and started studying older sources, it has to do with really understanding the reason why we use different techniques and what is the rationale for why you might use one approach rather than another. I can’t think of any area where maybe this is more necessary or more useful than looking at house division and really understanding what the basis is for some of these systems, especially since most people today don’t calculate charts by hand anymore. The mathematics behind some of this is a little bit obscure, I think, for most people.

LR: Yeah, I think so. What I’ve noticed progressively in students, which is unfortunately is a lack of knowledge of astronomy and celestial mechanics. Of course, back in the old days, almost every astrologer was also an astronomer and mathematician. Of course, you don’t need to be an astronomer or a mathematician to be an astrologer today because you have the tools for it. But we all as students of astrology should at some point really look in to these things, try to calculate all this by hand, even just to have the experience and the understanding, even if you keep it in your notes and never see it again. It has been years since I’ve calculated a chart by hand, except when I’m teaching students how to do it, but then it’s always the same charts. But still we should understand how everything is calculated. Also to have what Helena and I used to call astrological culture, not only historical, but also mathematics. You need to understand the mathematics so that you can understand the debates. You cannot understand the historical and eternal debate of the house systems, which one’s better, which one’s not, if you don’t understand at least a bit of the mathematics behind them. So I think that’s vital.

CB: I hope that’s something we’re going to try to explain today is some of those fundamental astronomical basics and make them clear and explainable, especially in a visual context for students of astrology. That’s an interesting point that you brought up because it’s only in the past few decades suddenly that people can practice astrology or learn astrology without learning how to calculate charts by hand, which is kind of an interesting shift in terms of it opening up the field and making it more diverse and more approachable. But on the other hand, we’ve lost a little bit in terms of that mathematical knowledge at the same time. And like you said, there’s so many famous astronomers in history who are also astrologers like Claudius Ptolemy or Johannes Kepler, or who are some others? Regiomontanus, maybe.

LR: Oh, it doesn’t end. Magini, Placidus, most of the people we are going to talk about today. I think almost everyone that worked with astronomy and mathematics until late 17th century would know a little bit about astrology, even if they didn’t practice it in interpreting charts, they would know a little bit about it, how it worked, and you can see that by the books. It’s there, the information is there for them to look at. So almost all mathematicians and astronomers before the 18th century would know a little bit about astrology and most of them would have practiced astrology at one point or another. I would think, even if only at part of their learning process, so the number is quite high, I believe.

CB: Yeah, and that brought up, there’s a debate that some of the astrological organizations have been having lately, which is whether for their certification process, whether knowing how to calculate a chart by hand should be required in order to be given sort of basic certification in astrology. Some of the organizations in the US right now are trying to decide whether to keep that requirement or whether to get rid of it, and whether it’s no longer appropriate to require that, which is kind of an interesting debate to have.

LR: It is. It is. I would be of the opinion that you should. It should be part. And people have to understand. I know that mathematics people run away about mathematics. Like we say, in Portuguese, like the devil from the cross, it’s something, oh my God, mathematics and people freeze, but we’re talking about very simple mathematics. You just have to know how to use the tables and you can have a calculator to do the whole mathematics of it, then it’s adding, subtracting, multiplying. So we’re not talking about circle trigonometry, I think that will be too much to ask of people. It wouldn’t hurt them, [laughs] but it’s a bit too much. So I think yes, every student should pass through that process of calculating a chart and understanding the celestial mechanics as we are going to talk about them today. Even if just to have an idea of how it works, and even if you forget about it at some point because you’re using the computer, at least you have an experience of the past or some notes where you can go to and just check and see how it worked, how it functioned.

CB: Yeah. I learned how to do the chart calculations at year two of Kepler College when they still had their academic degree program and I have since forgotten it. But I’ve been thinking lately about whether I could fit in a two-hour podcast like this like an instructional video about how to calculate charts by hand or if that would be something that you’d need to do a whole series on it or something like that.

LR: Well, I think you could. I must say, it would be a very boring podcast. [laughs]

CB: Yeah, it’s not the most exciting topic.

LR: Exactly. It’s not the most exciting topic and it’s very do this, do that and there’s a sequence of instructions. But yes, it might be useful for those who are not aware of it, certainly.

CB: All right. Well, if any listeners or people watching this episode want me to do that as a topic in the future, let me know in the comments below. But why don’t we jump into our actual main topic today, which is house division and where should we start when it comes to this topic?

LR: Well, we all already said a lot of things. So this is an ongoing discussion in history. Although I’m not certain if in the past they had as many house systems as we have today, I think today we have a proliferation. I’m not sure how the count is going at this point, but the last time it was around 30.

CB: Yeah. There’s probably at least like 30 different house systems. There’s probably at least a dozen or half a dozen that are more commonly used, let’s say, but then there’s also a bunch of like obscure systems as well. Yes, there’s quite a few different forms of house division and when we’re talking about forms of house division, we’re talking about, for example, Whole Sign houses or Porphyry houses or Placidus or Regiomontanus, Alcabitius, Koch houses. Those are basically some of the main ones I think, at this point in time.

LR: Yes. Yes. I did a survey recently where I try to ask people and I was particularly interested in practitioners of tradition. So people who at least had knowledge of tradition and the system that was now appearing in greater number was definitely the whole sign system, followed by Placidus and then the Regiomontanus and then Alcabitius. That’s usually, I think the distribution of percentages goes that way and then other systems will pop up, but not so commonly. Equal houses appears a little bit, but not as much as any of the others.

CB: Yeah. There’s different eras when different house systems tend to predominate or tend to be more common. The preferences for different house systems can change kind of like a thud almost in different time periods for different reasons related to sometimes astronomical reasons, sometimes mathematical reasons, sometimes purely cultural or historical reasons, different historical arguments. There’s a lot of different nuances involved in those shifts.

LR: Yeah. Even today, we can see how certain trends either because you have a famous author that uses a certain system or a school of thought that uses a certain system then suddenly systems that are more obscure appear or simply systems that were out of use at that period certainly gain a lot more preeminence in practice. So yeah, it changes a lot. Perhaps we should start with making a historical overview, a brief historical overview.

CB: Yeah. You have a great animation that shows sort of the timeline of the origin of some of the most popular systems. Right?

LR: Exactly. Exactly. So let me share the screen with you. So here we have the house divisions through time, so let’s build a timeline. I focused here only in pre-modern house systems. So I don’t extend the debate towards the 19th or the 20th century because then the house systems become too much, so many that it’s not easy to track them exactly on popularity. Of course, the oldest form and then well, I was going to use the word primitive, but not in the sense of sophistication, in the sense of earliest form of division is going to be the whole sign and due to its simplicity and–

CB: Maybe simplistic is a good term for it or simple.

LR: Simple. Yeah. It’s simple. So you’d only need to determine which degree is ascending at a given moment and then you build. We’re going to explain this a little bit better. Of course, most people know about this. So then you can divide attributing the sequence of each sign from the sign where the Ascendant is placed, it’s going to be the first house and following the sequence, each sign corresponding to an entire house.

CB: So this is the whole sign house system, or as James Holden called it, the sign equals house system?

LR: Exactly.

CB: Okay. So first century’s BCE basically is when the first charts with that show up and that therefore is one of the earliest documented systems and then for those listening to the audio version, the timeframe runs from there. Then it starts to fade by like the ninth and 10th century when the other quadrant systems really start becoming more dominant and then certainly by the Renaissance, by the end of the Medieval period, whole sign houses just kind of dies out completely in the Western traditions that we don’t see it mentioned in authors like William Lilly, or especially even modern authors in the early to mid-20th century until it was rediscovered in the west in the late 20th century.

LR: Yeah, exactly. Here, this timeline is of course focused on Western astrology or European based astrology. If we included the Indian practice, their system would continue throughout time to our current time. So, this is an approximation, of course. The diagram is approximate. It’s not intending to be the ultimate word or extremely accurate historically, just to give an idea. And like you said, Chris, the whole sign system seems to disappear around the ninth century. It starts to deem its use. We see it less and less and it’s being replaced by other systems which suddenly have appeared or at least start to appear in practice.

CB: Right, and that’s something I want to talk about later is why that shift happened and why it was somewhat dramatic and that’ll tie into our later topic of talking about the rise of the use of the astrolabe and how that could be used to calculate not just the Ascendant and Midheaven, but also the other house cusps for quadrant houses very easily. And whether that, one of my working theories is that that could have played a role in why that shift started to happen somewhat suddenly by the ninth and 10th centuries.

LR: Yeah. Yeah. Well, certainly the ability to calculate and measure with precision astronomical movement played a huge part on this, and here there is a mutual back… So there’s a mutual relation and back and forth between the creation of instruments and the development of certain mathematical systems astronomical or astrological. So that appears to be something that goes out throughout time. So as you have more needs for accuracy in interpretation, you’re going to have more accurate instruments being built to account that. As you are able to measure more then the mathematics of astrology becomes more complex, so you have that kind of play between these two facets.

CB: Yeah. Right, and we have some of that in the earlier tradition, for example, with the development of the ephemeris in the fifth century BCE in Mesopotamia, and then it’s around or not long after that time that we see the first birth charts from like 410 BCE forward because you kind of need to some extent if somebody was born 30 years ago, you need to be able to look up where the planets were 30 years in the past if you weren’t there to witness the planets at that exact moment, like visually. So sometimes astronomical innovations can spur on developments in astrology or sometimes astrological, you know, the desire to be able to do certain things with astrology can spur on certain astronomical innovations.

LR: Exactly. Yeah, exactly. It’s all the same thing. So it’s the same body of knowledge developing both technically and in ways of thinking and conceptually. So I think the two go hand in hand throughout history.

CB: Okay. So let’s go back. So whole sign’s the first, what’s our next system of house division?

LR: Okay. The next system is going to be the equal houses.

CB: Sorry. I accidentally pulled the screen back, so let’s share your screen again.

LR: Okay. So the equal houses will be the next step if we can call it like this. There isn’t an origin of the equal houses clear as in we don’t have an origin for the whole sign, it’s just there. It is apparently described by Ptolemy in the Tetrabiblos. There is a description which many authors interpret as being equal houses. Of course, throughout history, that’s going to be a debate what exactly Ptolemy meant by that division. But definitely he described something which appears to be equal houses. Sorry, you were saying?

CB: Vettius Valens also has a chapter where he describes equal houses and how to calculate them and it seems to be drawing on an earlier text from either the first century BCE or maybe slightly later, like first century CE attributed to Asclepius. So in my book on Hellenistic astrology, I proposed that there was this early text attributed to Hermes, which introduced the whole sign system and then there was another text attributed to Asclepius that introduced the equal house system. But those ended up being two of the earliest texts on house division from the beginning of the Hellenistic tradition around the first century BCE. And then Firmicus Maternus is the next person after that who’s in the fourth century that outlines equal houses also drawing on the Asclepius text.

LR: Yeah, exactly. Equal houses seemed to pop up throughout history a little bit. It’s difficult to track it and more or less in parallel with the whole sign. It seems to die out during the Medieval period. So around the ninth, 10th century. But, I’m not certain if there is any study that really can assess how used was the system at least in the Middle ages where we have more records. But this appears to be what we know about it at this point. It seems to fade away as more or less in the same period as the whole sign.

CB: I thought it was mentioned by some Renaissance authors or there’s some debate about that where somebody tried to revive it based on Firmicus or something like that.

LR: Yeah. If we go to the books where they discuss the house systems, I think even the whole sign still is there later on, because it survives in a lot of techniques and methodologies. So for example, you are seeing authors sometimes referring to the 10th sign from the Ascendant when they are studying matters related to vocation and not only to due to the MC degree. So that seems to linger on and certain techniques which have to do with planetary houses or houses extracted from planets seemed to use a whole sign system. I’m not sure if they are going to use or eventually an equal house system. So it’s always there. Even in more complex, I was saying even more complex debates in the Renaissance, you see them referring either to the whole sign or to the equal house system as being that of the ancients. So that idea, it lingers on much more than we realize throughout until the 17th century.

CB: Yeah. I just remember there’s this tweet from a friend of mine named Rob Bailey last year in July, where he said that astrologers Luca Gaurico and Gerolamo Cardano in the 16th century were bitter rivals in the early days of the printing press and Gaurico mocked Cardano for using the equal house system instead of a quadrant system saying that Cardano calculated houses like a bumpkin, which is like a, I don’t know, like a farmer or something like that. So it’s funny some of those debates were just lingering echoes of the equal house system where it sort of survived a little bit as a result of some of those authors like Firmicus being transmitted in Latin, but that it would have been looked at as a very simplistic form of degree-based house division, where you start from the degree of Ascendant and then measure 30 degree increments from there.

LR: Yeah, exactly. It was also in a certain way and in certain moments a way to cheaply calculate charts in printed materials. So I think the case of Cardano is that he has a huge collection of charts and the work involved in creating plates for all those charts for such a great number of chart in a printed book would be terribly expensive and a lot of work. So he simplifies it, he gives the data, he gives the Ascendant. If anyone wants to calculate the more complex house system, let them have, let them do the work and he just presents a simple structure. So there’s also in certain cases, I’m not saying in every case, but there seems to be also an economic reason to save a few work in the printing press, because printing a chart was very complicated. You would need to have either an engraving, like for example, you find later in Lily’s, those are engravings, or you would need to have certain types, you’d have to construct a chart from the types you had with dashes and lines and numbers, which it’s a bit of work.

CB: Right. For sure. Let me just share that tweet really quickly. It was Rob Bailey who is @oldschoolastro on Twitter, just to give him the proper credit for that in a little thread he did on house division at one point. And something I meant to mention actually is, in the mid-20th century, there was a revival of equal houses in the UK and I know that Margaret Hone through the, what was the school? There’s a school in the UK that became one of the main schools for astrology and they used her textbook, which advocated the use of equal houses.

LR: Yeah, indeed. Yeah. It was very, very common in the mid-20th century. I think it was one of the most used systems perhaps after Placidus, I’m not sure.

CB: Yeah. After Placidus and that still persists, there’s some astrologers, like I did an interview a year ago with Carole Taylor who taught at the faculty of astrological studies. That’s the one.

LR: That’s it yeah.  Faculty yeah, exactly.

CB: Faculty of astrological studies. So through that school and that lineage they’ve continued to pass that on in terms of using equal houses as their primary approach. So sometimes you’ll see interesting things like that in terms of the history of house division and certain systems popping back up or coming back into vogue and going out of vogue and coming back at different points.

LR: Yeah, certainly. I think it’s, for example, this systems which are simple I’m not sure what was their idea. But probably because it was easy to calculate, I’m not sure why they chose such a simple system.

CB: I mean, for me, I still use whole sign houses as the primary system of house division. Not because it’s simple, but because of the conceptual rationale that it has for the houses. So sometimes I think there are practical and conceptual reasons for it, even if you’re aware of potentially more complex systems.

LR: Yeah, certainly. It would be interesting to know just out of curiosity.

CB: Okay. So that’s on equal houses. What comes after that?

LR: Equal houses, so after that we have porphyry, what we call today the porphyry houses, although it is described much earlier. I think the earliest one that at least I’m aware of is Valens, who describes the porphyry system which divides the arc. So I think this is the first one, the first quadrant system that appears, the earliest one perhaps in which you have the MC degree and the Ascendant being accounted for the division of the houses.

CB: Yeah. There’s earlier references to like Valens, for example, in that chapter where he introduces the system in the context of the length of life treatment. It’s attributed to an earlier author named Orion, but it’s not clear in the text if Valens because Valens introduces an approach, but then there’s a modification of it. It’s not clear if it’s Valens himself, that’s modifying it or if it’s his source, which is the Orion text, but certainly at least by the second century CE we see it in Valens. Then you have an annotation here about when it was first used because we start to get some discrepancies between when we first have documented usages of certain house systems versus the author whose name later came to be associated with some of them, so Porphyry lived a century or so after Valens in the late third century, and that’s who that system ended up taking the name from for historical reasons.

LR: Exactly. Most likely it’s either the lore surrounding the house system that attributes it to a certain author or it was at a certain point the earliest known reference to the system. I think here they attribute it to Porphyry although Valens does describe it earlier on and attributes it to early authors. The simplicity of the system itself would suggest that it’s probably earlier. So all of these dates can perhaps be pushed to earlier dates, but we still need evidence for that and this is just supposition here.

CB: There was an introduction to astrology text that was written in Greek that was attributed to Porphyry, and Porphyry was like a famous third century neoplatonic philosopher, who was a student of Iamblichus, who was one of the very significant philosopher in the Roman Empire. But that text, that introduction of porphyry, I think it was still in circulation later during the Medieval and Early Renaissance period and there was a printed version of it, whereas Valens’ text fell out of circulation after the Middle Ages, basically. So that’s why this system would have been attributed to Porphyry and some later Renaissance authors, for example. I think you made a point when we were talking the other day that some of these names come from the Renaissance authors who were looking back at what texts they had access to and then trying to name some of these systems based on who they thought the earliest source was or who invented the system.

LR: Exactly. Exactly. So I’ll explain that a little bit later, but we have a whole storiography of the 16, 17 and later centuries where these names are going to be attributed although at the time they might not have this names originally as we’ll see further on.

CB: Okay. So porphyry is the first quadrant system that’s trisecting, it’s dividing into three the four quadrants between the degrees of the Ascendant, the degree of the Midheaven or meridian, and then the degree of the Descendant and the degree opposite the meridian.

LR: Exactly.

CB: So what’s the next system after that?

LR: The next one is Alcabitius, what we know today as Alcabitius system. Although again, as you see in the diagram, the earliest known example we have of this is in Rhetorius in the fifth century, and Alcabitius lived much later in the 10th century. So Alcabitius doesn’t really describe this system. He described something similar, but it could be a number of things. He doesn’t give you the mathematics of the system, so this attribution’s a bit odd.

CB: Okay. So, he’s Arabic name was Al-Qabisi, but we sometimes refer to it or the system is referred to by the little like Latinization of his name, which is Alcabitius. He lived in the 10th century and wrote a very popular Introduction to Astrology text, where it’s kind of funny because he criticized Abū Maʿsar who wrote The Great Introduction to Astrology, but it’s very long and it’s very dense. I think Alcabitius was a little bit annoyed and he sort of makes a remark about Abū Maʿsar being a little bit too wordy. So he wanted to write something that was kind of like in between the greater introduction of Abū Maʿsar, which was a really long text, but something more substantial than the lesser introduction to astrology of Abū Maʿsar, which was a very short, almost overly short and concise text. So Alcabitius wrote this like middle ground text and that actually ended up being very popular later in the late Medieval and Early Renaissance period where it got assigned as like assigned reading, I think, in some universities for doctors and things like that.

LR: Yeah. It’s one of the most famous introductions. So there are several introductions there, he’s a go guy. So the introduction to astrology in his is by far one of the most popular ones until late 16th century then others start to appear, but his was very important. It was one of the earliest astrology books to be printed because it was a basic. You had to have it, you had to read it to really understand the basics of the system.

CB: Okay. So he outlined some quadrant house system in his text, and that’s part of the reason why this system, which became basically the standard quadrant house approach during the Medieval period, why it gets attributed to him. But this is the point where we get into sometimes there being some ambiguity in the sources because the mathematics of one system can sometimes be similar to or very close to her or produce the same results as another quadrant house system. We do know for sure that at least by the fifth century that we see this system being used by astrologers such as Rhetorius of Egypt who lived in the fifth or sixth century CE.

LR: Exactly, and historians of mathematics and astronomy which are the ones that have studied this problem, because the calculation of the house system is a very interesting historical problem in terms of mathematics and astronomy. Because especially when you get to the quadrant systems, it requires methods of computation. So they have been studied, not in full detail, but at least in the perspective that the history of mathematics and astronomy, they are a case study of how astronomical calculation develops throughout time. And exactly what they sometimes have a problem with is either we have charts as you were saying that it’s indefinitely to know exactly which system are they using, because if they made an approximation in the calculation, there might not be sufficient distance from one system to the other. And from porphyry to Alcabitius, sometimes the distance is one degree difference between the house cusps. So if they’re doing an approximation, you might not be sure which one they’re using or sometimes when they are describing a house system they are not detailed enough to understand exactly what they’re talking. So sometimes the problem is that what they are defining can be a number of things. So it isn’t clear, so there’s a lot of problems there as well.

CB: Okay. Got it. But for the most part, Alcabitius becomes, and I know some academic texts refer to this as the standard system because it was so commonly used during the Medieval period.

LR: Yeah. It’s John D. North, which has the Horoscopes and History. His book is the seminal work on the house systems in academia. What he does instead of calling them the names that we call, he attributes alternative names more inclined to their mathematical nature. So Alcabitius he calls the standard system because it’s always described in the texts. And if we look at the Medieval chart, especially after the eighth century, it’s most likely an Alcabitius house system that is being used in the charts. So it’s very, very common until the early 16th century, 17th century still appears. I’ve seen examples of the 17th century very early, but then it is by then replaced by other systems, namely Regiomontanus, of which we will speak in a while but it’s still there.

And you can see, for example, figures like Cardano saying that although they use Regiomontanus as everyone else in their time… I think it’s Cardano who says that he likes the cusps that are calculated by what he calls the old system, and what he’s stating there is Alcabitius. So there is this back and forth of experimentations already by that time. But it is perhaps in historical terms as far as we know in the Western practice or in the European-centered practice the most popular of house systems in the tradition.

CB: Okay. So and this is actually your preferred quadrant house system or this is the system that you primarily use in practice?

LR: Yes. This is the one I use, and this is the one that my experiments with how systems lead me to choose in terms of results.

CB: Okay, and we’ll get into the mathematics underlying that system in just a bit here after this little historical overview. I meant to mention also in passing because you mentioned like J. D. North’s book Horoscopes in History, which is one of the primary academic texts on house division. I know there’s been also some other more recent work on different systems of house division in academic texts. Like you mentioned one of the authors who was doing some work more recently, his name is Julian.

LR: There’s Casulleras, I failed the first name at this point. He’s a historian of mathematics and he has works on the divisions and so the house system divisions and also the direction systems, the system for calculating primary directions in the Medieval Islamic world. So I think his papers that he co-authored with other authors as well are the latest that I am aware of in terms of the classification of the different systems that they find in the text works.

CB: Okay. Yeah, and then there’s been other work by… There’s another academic text, I’m struggling to think of the author who did like a paper on different Medieval systems of house division and he had also done that brilliant book about Arabic astronomy.

LR: Is it Julio Samsó? I think the one that you were thinking was Julio Samsó, who also did a number of texts on house systems. I’ve compiled a lot of information. And there is another, Kennedy.

CB: Kennedy, that’s it, yeah.

LR: Yeah, that comes after North. So North does the seminal work then Kennedy rectifies and adds more information to what North does, and then Samsó and then Casulleras are the ones that are continuing this research.

CB: Yeah. The paper, it’s actually an article or a paper by E. S. Kennedy. It’s titled the astrological houses as defined by Medieval Islamic astronomers. It’s a very good work. So there is a problem though, and there is a division and this gets into the murky issue. But in terms of the revival of rediscovering that whole sign houses was a concept, which from my perspective I thought until recently that James Holden, certainly in English, James Holden was the first both academic or astrologer that I knew of who really talked very openly about this, that whole sign houses was probably the original form of house division or certainly was the most common form of house division in the Greco-Roman period and the Greek texts from about the first century BCE through the fifth or sixth century. He did that first in 1984 in a paper on the different forms of house division. And then after that point we see other scholars like Robert Hand starting to publish papers on it, some astrological including a monograph and then eventually academic paper on it in Culture and Cosmos in 2006 or so. But also others scholars like Robert Schmidt and then more recently myself, and I did an episode, I wanted to mention, that talks about the early origins of the different forms of house division, which goes into that in a little bit more depth in the Hellenistic tradition. But that’s in episode 227 of the Astrology Podcast titled, the origins of the house division debate in ancient astrology. So I wanted to mention that because one of my issues that J. D. North and some of the other academic scholars is even though they’re very comprehensive for the quadrant systems of house division and they’re very interested in the mathematics underlying them, I do feel like there was this blind spot where because whole sign houses was lost for the most part by the 20th century in the Western tradition, there wasn’t a realization that that was actually used as a legitimate form of house division in the Greco-Roman tradition and in the Greek texts. J. D. North goes so far as to say that he didn’t think the Greek astrologers even used houses as much as some of the later tradition did, but that was actually just obviously quite false. It’s just that they weren’t using quadrant houses. They were instead using the signs as houses, which if you’re not aware of that can sometimes make it look as if they’re not using houses at all. But if houses are understood sometimes to coincide with the signs, then they were using them just as frequently as the later Medieval and Renaissance astrologers just in a slightly different way.

LR: Yeah, yeah. The problem with North and several other historians of mathematics is apparently that they’ve not considered the whole house system to be a house division, not in the mathematical perspective. So we could call, perhaps we’ll be talking about house systems, several systems of establishing the houses in the chart, but mathematically they consider that the whole sign is not really a division. It’s just an attribution of signs to certain topics or to certain houses starting with the determination of the Ascendant and then the determination is done in sequence. So for them that’s not the mathematically complex problem. They see it as a very primary and simple way of attributing the houses. So they’re not going to consider it in their studies because that’s not their focus. They want to understand how the calculus develops, the trigonometry, the projection of the different parts of the sphere onto the ecliptic onto the equator. So none of that is happening in the whole house system. So they’re going to ignore it. Of course, if we approach the topic from the perspective of the history of astrology, then it’s a whole other discourse. This is the interesting thing, because if you approach the topic of the houses, which almost no one has ever done, at least globally through the history of astrology, then you’re talking about practice and then you have to understand what is being used in practice. Here and the academic discussion so far have been mostly centered on mathematics. So the whole sign doesn’t pop up. Although, as I told you before, and I couldn’t find that reference, but I know it’s there somewhere. The earlier scholars of the Greek tradition Bouché-Leclercq and the scholars at that time, they are aware of how the chart is constructed in the Hellenistic period. So they probably don’t focus so much on giving it a name, but they are describing horoscopes and charts with whole signs houses. They understand that there are houses which are constructed from the part of fortune which are done by counting. I think that’s the word they use counting. The topics are described by counting the signs. So they are aware that that exists, but they’re not discussing it as a house system because that’s not their focus, I think.

CB: I’m not sure about that just because I know with some more recent academics, like in the past five to 10 years, I could see that being true that maybe they’re aware of that, but because they’re focused on the mathematical systems, that’s all they want to really focus on is cause that’s the thing that’s more interesting in terms of the mathematics underlying the quadrant systems. But I do think there was this period where academics like J. D. North didn’t realize the whole sign houses was a concept and it was a sort of blind spot. I’ve been trying to track back what the earliest references are to whole sign houses and I’m still unsure because I’ve read through Bouché-Leclercq’s L’Astrologie Grecque, which is like the primary academic reference text for Greco-Roman astrology for the past century was published in 1899 or something like that. But I’m not sure. There’s some places where he comes very close to almost describing whole sign houses, but I legitimately don’t know if he recognized that as a form of house division, because if he did, I think most of the academics subsequent to him would have recognized as well. But in most texts they seem to be unaware of it until Holden and then subsequently Rob Hand and some of those people started talking about it.

LR: Yeah. But you also have… What’s the name? By Neugebauer, the Greek Horoscopes, I think that’s the title if I’m recalling correctly. They have a lot of examples with whole signs, and they are describing them, the horoscopes. So they should be aware of what’s happening there.

CB: They should be. I’m not sure if they were, that’s the problem. That’s what’s so weird.

LR: I don’t think they’re discussing it or calling it a name because these are not historians of astrology. So they’re focusing on the mathematics and mathematical practices mostly. That’s why I think, so they’re not concerned with calling it a name. So you might be observing this phenomenon, although sometimes historiography has these huge blind spots that seem like huge black holes.

CB: Right. I did want to say that I found a book last year. So I thought Holden was one of the first people, both astrologers and academics because I found other books in English on house division from the 1970s, early 1980s. They just don’t mention the whole sign houses because they’re not aware of it as a concept in the astrological tradition in like the mid to late 20th century. And Holden was one of the first that explicitly named it and said, “This is an approach.” So I thought he was one of the first, but then I actually found a book that was republished just in the past year and it’s a German book from 1959 called Horoskop und Himmelshäuser by Dr. Walter Koch and Wilhelm Knappich. So this is a book in German from 1959 where they go through the different systems of house division. These were two astrologers, Koch actually was the inventor of the Koch system of houses, which became very prominent in the late 20th century and even still today many astrologers use, but they both had classical trainings. They could read Greek and Latin texts and they do talk very explicitly about the Greek astrologers using the signs as houses and talk about that as being like the earliest system and then how other systems were invented and developed after that point. So I wanted to point that out just because that means, at least in some German text, I don’t think this book was very well circulated and I didn’t find it in the Holden’s bibliography for example. But it means at least some of the German astrologers were aware of this way before, like three decades before James Holden was doing his work.

LR: Yeah, yeah. Well, the Germans in the ’20s and the ’30s decades of the 20th century are very active in astrology, and their astrology is a lot centered on mathematics, directions, calculations. So if there is someone in the earliest historiography of the 20th century that noticed that would be the German author. So perhaps that’s a place to look for for that reference.

CB: Right, for sure. All right. Sorry for that long digression, this just brings up a lot of stuff I’ve been working on of course for several years. So why don’t we get back to your presentation where we left off was at the Alcabitius system. So sorry, I keep stealing the screen back from you so I’ll have to share it again. Okay. So we’ve just talked about Alcabitius and that’s now becoming the sort of standard system from the fifth century onward, especially during the Medieval period. So what comes after that?

LR: Exactly, and then one system that is constantly being referred to, although I’m not so sure about how popular it was. I don’t have enough data on it. It’s what we know as the Campanus system, which as far as we know in terms of study is attributed to Al-Biruni or at least Al-Biruni describes the system and claims himself to be its inventor.

CB: Okay. [laughs] He lived in the 10th century?

LR: 10th century, yes. So I think the transition between the 10th and 11th century, so late 10th century, if I recall correctly. So in one of these tables, and I think it’s Julio Samso that detected this in one of his papers which is called, I think, entitled Al-Biruni, he detected this. So he’s describing what we later will be known as the Campanus system very early on, and there appears to exist several discoveries of this system. So several uses of this system from slightly different perspectives throughout the late 10th and 11th century in the Islamic European world. So we’re talking mainly the Iberian Peninsula and the North Africa. Why is it described to Campanus? I’m not sure. I’m not sure if Campanus ever did describe this system, but it appears to become popular in the 15th century. So 14, 15th century especially in the 15th century by this author, what’s his name? Is Johannese Gazulus. So I think it’s Gazulus, it’s his none Latinized name who lived in roughly in the first half of the 15th century and he created tables for it. He was working in Italy in Padua if I recall correctly, and he was an advocate, strong advocate of this system.

CB: You said that’s in the 15th century?

LR: 15th century, yeah.

CB: Okay, so that’s when it becomes popularized, and it’s attributed to Campanus of Novara, who was an Italian mathematician and astronomer and astrologer who lived in the 13th century?

LR: Exactly, exactly. So Campanus, although it’s a bit early, it appears more or less at the same time as the next system which is the Regiomontanus, what we call the Regiomontanus division. Which again, it’s one of the first descriptions appears to be by [inaudible 57.04] in the passage between the 10th and 11th century, although there are evidences in astrolabe plates that these systems might have been in use or similar versions of these systems could have been used before. I think one of the earliest is in the eighth century. So everything, all these dates can be much earlier than this. So one, two, three centuries earlier, but this is the data we have currently and it’s then popularized by Regiomontanus works.

CB: Regiomontanus was a German mathematician and astronomer and astrologer?

LR: Yeah, a very famous one and he wrote a series of tables and a series of works on mathematics. Very famous, he’s constantly being referenced in his own time and later, and he is more or less contemporary with Gazulli that I was referring to. There appears to have been, although this is highly understudied, a sort of a regional war between German mathematicians and Italian mathematicians as what would be the best house system. So there’s a nationality thing here [laughs] and Regiomontanus system wins over Campanus. But it is interesting to see different schools here in this case of mathematics and astronomy competing to have the most perfect house system for astrological practice.

CB: Yeah. There’s also some like textual and historical things going on because I did in episode 244 of the Astrology Podcast, I interviewed Anthony Louis and we talked about how did Placidus become the most popular house system was the title of the episode. We talked about how sometimes some of the different systems were coming into vogue because the authors were arguing that this was the system that Ptolemy meant to use or they thought that he described in his text. So sometimes certain systems were coming prominent for that reason.

LR: Yeah, exactly. All of these systems we see here are either attributed to Hermes, Ptolemy or some earlier author. And there appears to be evidences that some of the earlier authors appear to have used them or used similar things. The thing is nowadays most of our knowledge of house systems is extracted from astrology books. So if a manual in astrology described a house system worked or it has a chart example, but that is not the best source for this issue. The best source for this would be the tables. So the books that teach how to calculate charts and the manuals for instruments, namely the astrolabe, which we’ll speak in a moment. But those are the texts where you see them debating how to calculate house systems and that’s where the most of this information comes from. Because most of the time in an astrology book, they’re not going to argue which system they’re using. They’re just interpreting things and just going with it. They’re practicing, they’re not doing all the mathematical conceptual work in there. So for example, Regiomontanus systems which he calls the rational system, the module rational, the rational division, it’s discussing his tables of right ascension. It’s all these tables of ascension, it’s right there where all of this is worked. Yeah, and it is the most popular system in the early modern period and extending to the early decades of the 20th century.

CB: Regiomontanus?

LR: Regiomontanus.

CB: All right.

LR: You still find schools using Regiomontanus in the early decades of the 20th century, namely German schools of astrology.

CB: Part of the reason also there’s been a more recent revival of it because William Lilly I believed used Regiomontanus houses, right?

LR: Yeah. Well, if someone in the 16th and 17th century is using something else other than Regiomontanus, they will be a very strange case because it’s almost universal. Everyone uses Regiomontanus and you see in the house discussions when they explain the various methods in the mathematical books. They say the ancients, which we never know if it’s whole signs system or equal houses because they are not very clear on that. They describe Campanus division and then they jump into Regiomontanus as being the true way of dividing the house system. This is so universal that the system becomes I would say almost to a hundred percent usage at this period. There are here and there are a few exceptions, I think, but very, very few, very few.

CB: Okay. So yeah, and then Lily’s endorsement of Regiomontanus then because that was the earliest major English textbook on astrology, then held some weights or carried some weight with it and continues to where, for example, due to the traditional revival of like astrologer starting in the 1980s in the UK, starting to reprint in 1985, William Lily’s Christian astrology and use that again. There was a sudden revival of Regiomontanus where because they wanted to emulate that approach to traditional horary astrology from the 17th century, a number of astrologers then started using Regiomontanus again for horary, so that some schools of astrology now still endorsed that as the best system to use as a result of that emulation of William Lily.

LR: Yeah. Let’s say that almost… Well, the first line of reconstruction of the tradition was a little more than astrology of which Lily was a basis. And because it was in English, it was not in Latin or any other strange language, it had a lot of popularity. So when people were rebuilding and reviving, so relearning horary, they would be using the system that he was using. So, that’s the main reason why Regiomontanus is claimed to be the one that people use when doing horary, that’s because that’s how they learned. However, in different periods, people will be using other systems for the practice of horary. So that’s not exclusive of horary and that is perhaps a message that we should state here, is that until the 20th century, the late 20th century, there is no discussion on a better system for this or a better system for that. The entire practice is uniform. So you’re not going to use something for mundane, something for horary, something for nativities, you’re using the same system throughout your practice. There’s not even that I know I’m aware of absolutely no discussion on using different systems for different purposes. It’s the same system. They’re just arguing if it’s better or worse, but it’s always the same throughout the entire practice.

CB: Right, so in terms of the application to the four major branches of astrology; which are mundane astrology, natal astrology, electional and horary, once an astrologer picks a system, they tend to apply it to all of those consistently.

LR: Exactly, exactly.

CB: Just for historical purposes, I just had a good idea to date where we’re at right now at this time, in terms of the history of astrology which is just, if you go to astro.com or Astrodienst, then you go to their extended chart selection, there’s an option where you can switch your house system and the default system that it uses is Placidus, which it has here up at the top. But the other systems that it gives at this point in time are Koch houses, Campanus, Regiomontanus, equal houses, equal from the Midheaven, the hollow, whole sign houses, whole sign starting with Aries in the first, meridian, porphyry houses, there’s Alcabitius houses, some other miscellaneous systems like Krusinski/Pisa/Goelzer or Morinus houses, Polich/Page APC, a couple of versions of Polin Sripati, which is a Vedic system, Carter’s Poly Equatorial, I have no idea what that is, something called sunshine houses and something called [unintelligible 1.06.43] houses, but for whatever it’s worth, those are like the options in terms of the different forms of house division that they felt like making available or have had demand for in order to just like set the stage for what some of the standards are today in terms of different forms of house division.

LR: Yeah, exactly.

CB: Let me just pull up another thing again just for historical purposes for our own point here in 2021. I can pull up astro.com, or not astro.com, I can pull up Solar Fire and I won’t share it, but the different forms of house division that they give are Campanus, Koch, meridian, Marinus Placidus, Porphyry, Regiomontanus, Topocentric, Equal houses, Zero Aries, solar sign, then they have a bunch where you just put a planet on the first and do derivative houses from that planet, whole sign houses, Hindu Bhava houses, Alcabitius, lot of fortune houses and that’s pretty much it. So I just thought it would be worth stating in terms of like the top systems that are commonly available to astrologers today in the different systems of house different programs or astrology software programs. Most of those, the core ones that astrologers actually use are the ones that we’ve just gone over in this overview. What was that the last house system Regiomontanus or did you have Placidus in there?

LR: I have Placidus, also. Yeah.

CB: Okay. Let’s do that one then really quickly.

LR: Yeah. One of the strange things just before we start with that, of these listings is I have no idea why they are not by alphabetical order, because–

CB: Right, I noticed that, too.

LR: –at one point, I thought, well, they arrange it by popularity, which I would understand, but not really. [laughs] So most softwares have this random order of house systems which is quite weird. But well, I have no idea why. [laughs]

CB: That’s a good point. So it’s like astro.com does Placidus at the top which is their default, but then they do Koch, Campanus, Regiomontanus, Equal, whereas Solar Fire in their order has Campanus, Koch, meridian, Morinus, Placidus. So it is very sort of random.

LR: Yeah, exactly. For example, Morinus is usually up top, and Morinus is a very, very obscure system. I doubt if there’s anyone using it at this point in time.

CB: Yeah. It is pretty obscure. All right. I’m going to have you share your screen again, sorry. [laughs]

LR: Okay. No problem.

CB: All right, and just for the audio. So the last system we described is Regiomontanus and then the last one, the last major one that we have to mention at this point is Placidus.

LR: Yeah. So Placidus, the Placidus system is our last major player in the pre-modern world, let’s say. So everything that’s 17th century, early than the 18th century to be more correct. Placidus is a strange system and we’re going to see that later on. Oh, sorry. I had some sort of failure here. Okay. So as I was saying, so Placidus system is our major player here, the last one in the early modern period. And it’s a strange system because it is extremely complicated mathematically. So it is believed that authors were aware of it since the eighth century, there are some evidences that it could be there in their minds and there are some descriptions of what it seems to be Placidus approach, but it is very complicated to produce mathematically. So they’re not going to go into it. It’s only when mathematic evolves with the equations that simplify the calculation, that they are able to calculate it with precision. So it seems to be avoided by astrologers and so by astronomers because of this. This is at least what historians think at this point. The first description of this system appears to be Ibn Ezra, and Ibn Ezra is attributing it again to Ptolemy, Hermes, Dorotheus, Mashallah, and someone else I can’t recall call at this point, but he appears to be ascribing it to earlier authors. There are some historians of mathematics who thinks that Mashallah is describing something that seems to be a Plascidus system somewhere. I think most of these descriptions will not be in the astrological works, will be in other mathematical works that we usually not study.

CB: So I know that normally the name of the system it comes from the 17th century. He was like a monk and a mathematics professor and astrologer named Placidus de Titis or Placido de Titis, and he published a work in 1650 that popularized that approach. But then I think Holden says that it’s already described by Ibn Ezra at least by the 12th century, and then Ezra saying it could go back even earlier, but we’re not fully sure.

LR: Yeah. Magini, which is a few decades earlier than Placidus also describes this system as well. And what the mathematicians call this system and perhaps it’s a better name is the hour line system. We’re going to understand exactly why in a moment when we explain the different mathematics, but it’s called the hour line system. And then Placidus work it’s so concise and so well presented that it becomes the standard system, at least in the English speaking world and I think that’s also to do with a translation that it’s done of his work very early on.

CB: Into English, as well as some of the historical arguments about arguing that it represented what the ancient authors intended or other things like that like Ptolemy?

LR: Yeah. Yeah. That’s always the case, every system here I think is going to be argued as being the original, the one that Ptolemy intended, et cetera, even when that doesn’t make any sense. It’s very difficult to understand how are they getting to that conclusion, but that’s always the presentation.

CB: Yeah. Okay. So that’s the historical overview, [laughs] and this is something that I think that was supposed to take like a five-minute historical overview, we just turned into 75 minutes. So at this point, should we transition into talking about how these different systems divide the chart?

LR: Yeah, exactly. I think that would be a good point to do that.

CB: Okay.

LR: Okay. So let’s move on in the presentation. So we have to introduce a few concepts here in terms of celestial mechanics before we go into the divisions. The first one is the existence of the celestial equators, which is a projection of the Earth’s own equator into space. So in the celestial sphere in the sky that we see, and because this is emulating the Earth’s rotation, every movement of every celestial object will follow as we were going to see here the equator. It will always move parallel to the equator, so it will rise, it will culminate in the line that we call the meridian, and then it’ll set in the west and it will do again the anti-culmination again at the meridian. Then again, rise in the east after 24 hours, which is called the primary or diurnal movement. So every point in the heavens is going to do this turn always parallel to the equator in 24 hours, which is the Earth’s rotation. So it’s the result of the phenomenon of Earth’s rotation.

CB: Okay. So, this is most easily visualized with just thinking about how the Sun rises each morning in the east, and then eventually culminates in the middle of the day and then eventually sets in the evening in the west, and then eventually around the middle of the night, it reaches the anti-culmination and then eventually it rises again the next day 24 hours later. But that process of the primary motion, it’s not just the Sun that does that, but also the Moon will rise and culminate and set. And all the other planets and stars in the sky will do the same motion of rising and culminating and setting each day.

LR: Exactly, exactly. So the entire celestial objects will do this movement. So this is going to be very important because this is the movement that we can observe very easily. So it’s difficult to observe planetary motion in the signs which is where we’re usually focused as astrologers in terms of interpretation. But this is what we observe every day if you just stand a few hours looking at the stars or looking at the Sun, experiencing the Sun. You can see it moving very fast.

CB: Right. So this is one of the two major movements. One of the movements is the planets moving along the ecliptic or through the signs of the zodiac, but they tend to do that very slowly. Even the fastest planets tend to move through the zodiac relatively slowly so that you have to go outside and view them over really long periods of time in order to see any movement against the backdrop of the stars. But this second movement which is actually what we call primary or diurnal movement happens every day over a 24-hour period. Each of the planets and stars and other celestial bodies do a complete movement in basically a day and a night.

LR: Yeah, exactly.

CB: Okay.

LR: So the signs in the ecliptic is going to do this very same movement. So all signs will rise, culminate, set, anti-culminate, and rise again in 24 hours. So in 24 hours the ecliptic is going to do this motion, but the ecliptic because of the tilt in Earth’s orbit is going to be slightly off. There’s a deviation from the equator. It’s what explains the seasons because the Sun will have different heights according to the sign where it is at the given moment of the year. It explains why certain signs rise faster than others and the difference in their rising and setting in different areas of the world. So this is going to explain a lot of the phenomenon we observe throughout the turning of charts and seeing how charts move throughout the day. And this is going to set these points, and here we’re not talking about any house system in particular. This is a very generic way of saying an Ascendant will always be the point of the ecliptic that’s rising in the east. The Descendant, the one that’s setting in the west which is the opposite point, the Midheaven or the MC is going to be the degree of the ecliptic that’s culminating at the given moment, and of course the IC also known as the angle of Earth is going to be the opposing degree which is anticulminating at that point. And it’s from this structure that the idea of house divisions appears.

CB: Right. And just hold on, linger on that last one for a moment. So it’s not just that the Sun rises over the eastern horizon each morning and then sets in the west each evening. And it’s not just that the other planets rise over the eastern horizon at some point during the day and culminate and set, but also the signs of the zodiac will rise up and emerge over the eastern horizon and then eventually culminate overhead and then eventually set each day as well. And that’s the concept of the rising sign, and that gives rise to the concept of the Ascendant. And it’s because we call it that. We call it the rising sign or the Ascendant because that’s the sign of the zodiac that literally rises up or emerges over the eastern horizon at either the moment of birth in a birth chart or at whatever that moment is that you’re casting the chart for.

LR: Yeah, exactly. Exactly. All our mechanics of the heavens comes from this motion that drags the ecliptic so the zodiac and the planets which are moving in there in 24 hours throughout the time and even in watches. So analog watches the moving of the pointers of the hour follows exactly this motion. The clockwise and anticlockwise motion has its origin in the astronomical movement, so it’s emulating again what is observable by experience when you look at the heavens daily.

CB: Could we go back and look at that animation again of the signs just one backwards?

LR: Yeah, sure.

CB: Just because that’s so useful to see the signs of the zodiac and how they rise over the horizon in order to really understand that concept of the rising sign which is really, that’s the fundamental basis of where the houses start is just with that notion of identifying what is the sign that is rising or emerging on the eastern horizon. And then you freeze it. For example here Gemini is rising, and that becomes the Ascendant. But something that trips people up sometimes is the fact that the diurnal motion it moves, like you were saying, clockwise whereas the planets move through the signs of the zodiac the opposite direction which is counterclockwise. And what’s interesting about that is that leads to a little discrepancy then where we actually number the houses based on the direction of the signs and the direction of the movement of the planets through the signs of the zodiac. So you start with the Ascendant becomes the first house and then you go downwards towards the second house then the third house and so on and so forth.

LR: Yeah. Yeah. We’re going to see that exactly in the next animation, so I might go forward with that.

CB: Yeah.

LR: So let’s imagine this is a division of some sort. This is not representing any system. It’s just dividing simply by 12. So again here we see what you were saying, Chris. The numbering is made in the opposite direction of the movement most likely because it’s going to be the first segment that rises, the second segment that rises, the third segment or the third sign that rises, etc. So it’s following the sequence of rising of the planet. So whatever it’s in the 12 has already risen, so it’s not going to rise for another complete rotation.

CB: And also because in the whole sign system because to whatever extent that was one of the earliest systems once you establish the rising sign, then you just number the signs in zodiacal order from there downwards because that’s the order of the signs, that’s also probably why that’s the order of the houses as well.

LR: Yeah, yeah. Exactly. It’s the counting. Yeah, the counting from the rising sign. Yeah.

CB: Sorry just to interject, but what’s interesting about that is there is possibly an earlier system from the Egyptian tradition based on the decans where they would look at the rising decan which is like a 10-degree area of space where the Ascendant was. And they’d look at which decan was rising, the number that going downwards as well.

LR: Exactly, yeah. Yeah. We have to think that this is connected also to the measurement of time, the measurement of time, the understanding of astronomical motion and astrology, so the interpretation of celestial motion. Everything is connected into one single entity initially. So the decans have also to do with not only interpretation wise but also to the counting of time. So what’s rising, what’s culminating. You can more or less measure time being it measuring in terms of quantity or measuring in terms of quality when you’re making the judgment. So, yeah, that’s quite clear.

CB: Although it’s interesting that these were separate reference systems from almost different astrological traditions at one point where you have the Mesopotamians who are really focused on the zodiac and the movement of the planets around the ecliptic and through the signs of the zodiac versus you have the Egyptians focusing on the decans and which decan was rising or culminating or setting at different points. And then what we see here basically starting in the first century BCE was the synthesis of those two separate reference points into one system where you get the signs of the zodiac and the diurnal movement sort of synthesized or fused into one approach.

LR: Yeah. Yeah. I think we see that in a lot of quarters. If we look at astrology, it appears to be a mix of several traditions that start to be combined into a whole system that then develops by itself.

CB: Mhm. Okay.

LR: Okay. So here we are. So this is going to be the cusps if we’re dividing it by that way.

CB: Right. Once you’ve established the four angles, then the four–

LR: A division of some sort. Yeah.

CB: Right. The four quarters of that circle get divided into quarters, and then those quarters get divided into thirds basically.

LR: Yeah. Yeah. Here what we see described is a sort of equal house system very roughly, and this doesn’t have any astronomical value because it’s not projecting any specific time. It’s just an explanation of how it moves. Yeah. Here we are is the signs moving throughout the houses again, so these spaces are going to be moved upon if you consider them as spaces or if you consider that it’s the signs themselves create the houses as they go. Yeah, so this is the idea. That’s–

CB: So you’ve got 12 signs of the zodiac in 12 houses.

LR: Yeah, exactly. So there’s a connection there evidently. Okay. Now we come to starting to approach the problem of the house systems which is going to be the matter of division. So if we consider, and I’m going to use the example of five degrees of Taurus rising for the latitude of Lisbon because that was the example I had prepared initially. If we consider that five degrees of Taurus is rising, the 90-degree position to that point is going to be five degrees Aquarius. So Aquarius will be the point that is exactly nine degrees from the ascending degrees measured in the ecliptic. However, because we have a discrepancy between the equator which is where the movement of rising and setting is being made, it’s the motor, the motion, the origin of the motion, there’s going to be a discrepancy here. And if we measure 90 degrees in the ecliptic, it’s going to be different if we measure 90 degrees in the equator. So 90 degrees in the equator, it’s going to cover in this case for this latitude to 105 degrees in the ecliptic. Then you don’t have the MC at five degree Aquarius, you have it in the meridian. So that line in the center of your observation area in the sky, it’s going to equate to 20 degrees Capricorn at the latitude of Lisbon. In a different latitude, it will have a different value. So here it is one of the first problems. When we are saying that we are dividing the quadrant, are we dividing the ecliptic? Are we dividing the equator or something else? And this has been a discussion that’s come up a lot recently in the practitioners tradition because that point in Aquarius, that five degrees Aquarius is going to be what is called the nonagesimal. So the point of the ecliptic that is in 90 degrees from the Ascendant. It’s going to be the point in reference to the Ascendant that’s going to be at the highest level. However, it’s not the point that’s going to be at the center of our observation field. So the meridian is always south as we’re going to see in the diagram. If you’re watching south and you’re trying to understand the exact point, the midterm of the movement of the diurnal movement, the Midheaven will be the point where things are culminating. So there is this difference, but it’s not going to be necessarily the 90 degree from the Ascendant measured in the ecliptic. And this is going to cause some trouble at least early on.

CB: Right, Yeah. Fundamental issue of house division is just how to divide the circle and what method to use to divide the houses into 12 sectors. And then there becomes an issue also about the use of the Ascendant as the starting point for calculating the houses and then also the use of the Midheaven and what you consider to be the Midheaven and whether it’s the meridian or whether it’s the nonagesimal which is exactly 90 degrees or what have you.

LR: Mhm. Exactly.

CB: I like this diagram partially because you’ve colored the bottom half below the Ascendant brown because anything below the Ascendant/Descendant axis is actually below the Earth from the perspective of the observer where you kind of have to imagine you’re standing in the middle of the chart, any chart that you’re looking at. And anything in the bottom half of the chart at least below the exact degrees of the Ascendant/Descendant axis is below the horizon or below the Earth. And anything above the Ascendant/Descendant axis is above the horizon and is in the sky and is visible in the top half of the chart basically.

LR: Yeah, exactly. Exactly.

CB: So with the meridian, do you have any other slides to explain the meridian or to dwell on that because I’m not sure if that’s clear? Or would this be a good time to switch to something like Stellarium to show what the meridian is.

LR: We can switch. Yeah.

CB: Okay.

LR: Yeah, let’s switch to Stellarium and see this in another way. So let me do here in your share. Okay. Here we are seeing the same thing that we have been seeing in these diagrams. But here with the projection where we can see in blue the equator, this is again for the latitude of Lisbon. In orange we are seeing the ecliptic. Here it is, the Sun, Mercury, and Venus see the planets very close to the ecliptic degree. Yeah?

CB: Let’s dwell on that point. So the ecliptic then as we can see here is, cause we didn’t really define what that is earlier, is the path of the Sun and the other planets from our vantage point around Earth. And it’s actually a very strict path or sort of band where they stay on this specific path where they move through the sky. And that’s actually how ancient astronomers and sky observers first identify the planets is that you can see them moving as these little stars that will instead of staying fixed like the other fixed stars, they actually start moving across this very strict predefined path which is the ecliptic or what later became known as the zodiac.

LR: Exactly. And here because we are having an astronomy program and not an astrology program using degrees. So 120 degrees we see there where the Sun is is equivalent to Leo, 150 is equivalent to the beginning of Virgo, so zero Virgo. 108 is zero Libra which is right on the equator. So it’s where the ecliptic and the equator intercept. It’s going to be in zero Libra and zero Aries, so that’s why they’re called the equinoxes. So when the Sun’s there, there is an equal amount of day and night and when the Sun is off that. So in this case, for example, this is the Northern Hemisphere. The Sun is above the equator in the ecliptic, so it will take longer to do its path. The Sun will make a path, a trajectory throughout the day to rise somewhere here near the east and will follow a trajectory which is more or less parallel to– Well, it’s not more or less, it’s parallel to the equator. And then it’s going to set somewhere here at the north of the west. Because it’s above, it’s going to spend more time in the sky. So we have longer days and shorter nights. It’s only when it is exactly in the interception in the equator so in this 180 degrees or in zero degrees so that’s zero Libra and zero Aries that the trajectory will follow east and west exactly so the day and night are equal. Because it is equal distribute according to the horizon or to the below and the above.

CB: Right.

LR: Okay.

CB: And so one of the points we’re making was that the tropical zodiac is basically a measurement of space or a number of degrees that’s measured out from the spring equinox from zero degrees of Aries which is zero degrees or the starting point of the ecliptic. And here we actually have–What is 270? I’m trying to count that up really quickly because we have about 270 of the ecliptic is rising, it’s not exactly east.

LR: It’s Capricorn. Yeah, it’s early Capricorn. So 270, it’s zero Capricorn. So that’s going to be probably two, three Capricorn rising at this particular point in time. Yeah.

CB: Okay, so that’s one interesting piece. Then this is one of the things that complicates the house division issue is that the ecliptic isn’t always exactly due east, but sometimes it fluctuates and can be more north or south basically at different times.

LR: Yeah. Yeah. So in terms of the motion, this is our grid. You have the meridian right on the middle, so half the motion until it hits the meridian. And the second half of the motion will occur after it hits the meridian. The green semi arc that we see there it’s called the prime vertical. Let’s not look at that at this point. I’ll explain what it is later on. But if we animate it, perhaps it’s easier. Let me check if I can animate this. Let me accelerate this a bit. So if we accelerate this animation, here it is. This is a nice base. We can see the Sun is going to set now. And you can see the difference of height in, sorry, I just need to do something on my computer. But you can see the different movements of the zodiac.

CB: Yeah, so the ecliptic can sometimes get higher or lower during the course of the day, what we’re seeing right now is the Saturn and Jupiter just passed over the meridian, and the meridian is the quadrant Midheaven. Now we see the Moon is passing over the meridian. And whenever one of the planets pass over the meridian, that also is their highest elevation at that point in the day.

LR: Exactly. So in terms of motion, any point of the sky will hit its highest elevation when it hits the meridian.

CB: And so that’s interesting in terms of the planets, and then we can see then why the degree of the quadrant Midheaven would be considered like a point of power or when a planet is at its height although it’s kind of interesting in terms of some of the other arguments for like in terms of the nonagesimal with the quadrant or with the equal house system where the Midheaven is at the 90-degree point relative to the Ascendant. And that’s basically the highest point of the ecliptic at that moment in time. And sometimes the ecliptic can actually be higher in elevation than the planets are at that moment.

LR: Yeah, we need to focus on the point. Yeah, because that elevation is majored always towards a degree of planetary position, etc. for example. For example, Saturn is culminating now at this moment. But this area of the ecliptic where the Moon is is much higher is actually the horizon. Yeah.

CB: And I think that’s where when it comes to this whole house division debate we run into an issue because both of those seem, let’s just say, from a symbolic standpoint in terms of symbolism and omenology or what have you, both of those are symbolically significant in some way like the highest point that a planet gets to versus the highest point of the zodiac at some moments in time. We could see how both of those could have some sort of independent symbolic significance, so that’s why it may not be entirely one or that it has to be one or the other but they both could be relevant in some general way.

LR: Perhaps. Perhaps. Yes, we do have that idea of a planet being elevated over another when exactly it’s doing a superior square to that planetary position. So it overpowers the other planet, and that remains in an aspect even if it’s not in that position. But it will be at a certain point in time zodiacally speaking. So it carries that power because through its motion it’s going to get that higher vantage before the other planet, so it wins. It has a higher ground first. And this is a genesis of the symbolism. But I think the problem then is that, how do you account for this culmination? Is it a zodiacal culmination in the sense that it’s the ecliptic that determines that? Or is it the meridian where you observe that point coming into its place of power? So that’s where the debate the initial debate comes regarding the nonagesimal and the MC.

CB: And so one of the things that’s important to understand about the meridian is that the meridian is also exactly where the due south, the north-south axis is. And so it’s exactly halfway in terms of directionality between east and west.

LR: Exactly. Exactly. Exactly. For those in the Southern Hemisphere, all this motion is going to be happening towards the north and not towards the south. That’s the main difference. Okay.

CB: Okay, cool. I think that’s pretty good.

LR: Yeah, let me just stop this. Okay, we can go back to it if we need. And let me go back to here at this point where you had this difference in the chart where the Midheaven would be in one way or the other.

CB: Sure, so you are showing how if you have five degrees of Taurus rising at the latitude of Lisbon that if you measured 90 degrees, well, you have the meridian on the one hand which in this instance would be at 20 degrees of Capricorn versus if you just measured 90 degrees upwards to the nonagesimal which is the 90 degree point in the ecliptic. That’s like the highest spot in the zodiac versus the meridian which is showing the north-south division line.

LR: Exactly, exactly.

CB: Okay, so that becomes tricky because different house systems define the Midheaven in different ways to some extent in a sort of loose sense so that in the equal house system the Midheaven is always exactly 90 degrees from the Ascendant whereas in any quadrant house system the Midheaven will move in relation to the Ascendant. But that still nonetheless is the starting point of the 10th house cusp.

LR: Yeah. And I think also something that has to be counted is that visually in terms of observation it’s much easier to detect the meridian, to determine the meridian from your local space, local horizon than to determine the highest point of the ecliptic. Because it’s easier to measure not only with the eyes but also with an instrument, which creates a discrepancy between what you can see and what you can measure. So we have to say that, for example, for most of the time of the history you do not have a representation of the zodiac as a ruler like we have here in the chart because it’s highly complicated to draw this, and to draw this consecutively would be difficult. So you have an equal wheel, either square or round, an equal division, and you just mark the signs or the cusp degrees. So it’s symmetrical in that way.

CB: Oh, right. You’re saying that not all previous chart displays were proportional like they are today but instead they tended to be more standardized in terms of the divisions?

LR: Exactly. You’re not seeing the zodiac. You don’t see this zodiac. It’s very rare if it exists. I can’t recall at this point an example where they draw the zodiac. This is, I think, perhaps the late 19th century or even 20th century development. Because it’s easier to print. It becomes easier, and the computer does it for you. So, yeah, it’s easy to display it like this. Yeah.

CB: Chart styles change from era to era and from tradition to tradition because sometimes in like the early Hellenistic tradition you did have just the zodiac and they would just tell you what sign the Ascendant is located. And then that’s the first house, and then they would just list the sign that the rest of the planets are in because then those are in the other houses relative to the rising sign. So it really shifts and changes depending on what era we’re talking about.

LR: Mhm. Yeah. Yeah, a lot from simple lists to more complex diagrams. But what we see, I think, consistently throughout history is that they never draw a zodiac like we see here at this point because it’s too complicated to draw an image like this by hand or with a quill. It’s going to be difficult to do this. Even circular charts are not favored on all parts on every time of history. It depends really on the medium in which they are drawing the chart. Because for example with parchment or paper, it’s not easy to draw a circle there. You need a compass, and that takes a lot of time. So they usually select the square chart.

CB: Yeah. Let me show an example of a square chart from Lily just to back up that point that you’re making just because it’s interesting to understand the way that charts are conceptualized in different eras. So here’s a square or a diamond chart pattern from William Lily’s Christian Astrology from 1640. Looks like this chart is set for 1646.

LR: Yeah. And here you see the house sizes are equal in that sense. So the emphasis is on the space being divided equally, whatever that means in mathematical or astronomical terms. And then the differences will be on the cusps. You will only notice different house systems if you look at the cusp numbers. So if you’re looking at one of these charts with eyes let’s say one with Alcabitius, the other one Campanus and Regiomontanus, it’s difficult to identify which one is which unless you do the calculations and see exactly the calculations of the cusps to make the difference. There’s a certain evenness there on the houses, centered on the houses.

CB: Yeah, that’s a really good point. So there’s a lot of abstraction going on in terms of taking that three-dimensional visual image that we were just looking at in Stellarium and then projecting that onto a two-dimensional image. Sometimes things get flattened out and look much more simple than they actually are astronomically.

LR: Yeah, exactly, exactly.

CB: Okay. All right, so let’s go back.

LR: Let’s now begin our–

CB: You have to share your screen again.

LR: Yeah, here we are. And I’m going to… So let me start the animation again. Okay, so now let’s move on from this topic of the community. Let’s start to look at the different reference points in which the divisions will take place. I think now we can start going for our divisions. Okay. This is my attempt to make a 3D’d version of what we’ve been seeing so far. So let’s say that this is the horizon, so the celestial sphere. So and you have the observer in the middle. The space of the observer is going to be divided by the four cardinal points. So south, east, north, and west. And then the point right above the observer’s head, the zenith and then the nadir which will be the point just below the point of observation. And this is the six directions of space of which the seventh is the center, so you need these six points in space to determine a location in the sphere.

CB: So the six points are north, south, east, and west, and then straight up above your head and down below your head. And it’s always relative to the perspective of the observer where they’re placed on Earth at that point in time.

LR: Exactly. Exactly.

CB: Okay.

LR: This is your placement. So the local space, let’s say. Then you are going to divide this further on into the meridian. The meridian is going to be what is called a great circle. A great circle is any circle that would roll in the sphere that divides it exactly in half. So every time we draw a circle in the sphere that cuts it in exactly half, that will be a great circle. So here we have two of them. One is this, the meridian, sort of brownish yellow. That’s going from north, zenith, south, nadir, north again. So it’s cutting the sphere in half north towards south. And we have the horizon itself which is going to be a great circle here as well as it cuts the sphere in half with our observation points. Then we’re going to have another one which is the complimentary one to the meridian which is called the prime vertical which is going to cut east, zenith, west, nadir. So this is dividing, and this is where the quadrants come from. So this is dividing the sphere into four parts. It’s like you’re observing something and you divide your observation point in the middle. So what’s in front of you and what’s behind you, that would be the meridian because you’re observing south. And then you’re going to do extend your arms and do another great circle from east to west passing over your head and getting back to the other side. So this is going to divide into in front of you, behind you, towards your right or towards your left.

CB: Okay.

LR: This is the division of space.

CB: And when it comes to the zenith, there’s like a little bit of discrepancy or confusion because sometimes different people use the term zenith to mean different things. And I know we were talking about the other day that there is a distinction between the meridian versus the zenith being separate concepts, right?

LR: Exactly, yeah. The meridian passes through the zenith, but it’s not the zenith. The zenith is the point right above your head. It’s a very simple definition, straightforward on your head. It’s not something that is going to appear in a chart unless you’re talking about a projection. We’ll see that in a moment.

CB: Right. Okay.

LR: So this is the local space, the structure of your local space. And then how do you divide the celestial sphere from your point of observation?

CB: Okay.

LR: Then you have the celestial referential. So how do you measure the planetary and star movement in the sky? So you’re going to have a new set of systems. You’re going to have the equator which we already seen. So the equator will transverse the heavens from east to west at a given altitude, and this altitude varies according to your latitude. So the more south you are, the more upwards the tilt will be. If you’re in the Earth’s equator at the latitude zero north/south, then the celestial equator will be right above your head and then it will coincide with the zenith. That’s the only point in the Earth. Yeah.

CB: What are some cities where you’re at zero degrees? Do you know roughly or countries?

LR: Well, Ecuador. [laughs]

CB: Ecuador. Okay. That’s pretty straightforward. Yeah.

LR: Yeah. Yeah. If you go to Ecuador City, it is quite close to the meridian. Then you look upward and you see the entire heaven just passing through above your head. That’s why the closer you are to the equator, the fast the sunrise and sunsets are. Because the Sun is coming straightforward from the east. So it rises very quickly, and it’s going to go down very quickly towards the west. Well, if you are in north let’s say Scotland, there is going to be an inclination. So this is the inclination of the celestial equator in the Earth’s equator. And then if you are in, for example, let’s say Scotland or somewhere up north, it’s going to do this. So it means that whenever is rising, it’s going to take long more time.

CB: Yes, do that hand motion again just because I want to make sure you’re on the screen for that.

LR: Yeah, so the Sun is going or whatever is going to rise a long time.

CB: And that’s if you’re on the equator?

LR: No, if you’re out of the equator up north.

CB: Okay, sure. Let me share just from Wikipedia to help people visualize this literally just a map of the equator and what we’re talking about in terms of where the equator is in terms of the middle of the Earth and in terms of latitude versus being north of that. For example, all of the United States or all of Europe is pretty far north of the equator versus countries that are south of the equator.

LR: Yeah. Yeah.

CB: Got it. Okay, so back to what you were saying.

LR: Okay. And perhaps we can see this on the Stellarium. Let me see if I can put that up because I think that’s interesting. Because it’s going to pop up in the houses. Let me share the Stellarium here. Okay, let me change our perspective here and move towards east and center our observation on east. So as you can see at the Lisbon latitude, the equator has this inclination. And the ecliptic will have this one. So if I can put this a bit straight forward. So, yeah. You see? Here we have the equator’s angle at this latitude. If we move to another place on Earth, let me change our location, where is it? Is it here? Yes, it is. So let’s pick Ecuador here somewhere. Let me–

CB: I think you can search or I guess you’d have to have a couple of–

LR: Yeah. Let’s put it right on top of the equator, so we can see. Exactly. Zero, zero, zero, zero, south or north. Okay. And here we are. See. You cannot distinguish from the prime vertical or the equator. See, 14 hours. The equator is straight line up.

CB: It’s exactly due east.

LR: Yeah. And if we put things in motion for example so that you can see the motion, here it is. See? Things are coming straight up. The ecliptic is going to be a little bit off, of course. But as you can see, things are rising very quickly because they are going just straight up there.

CB: Okay.

LR: This is the good about these programs because you can see it very easily.

CB: Yeah. For those curious, this is actually a Freeware program. It’s a free astronomy program called Stellarium. If anyone wants to Google and download, that can be useful for learning the observational astronomy underlying astrology.

LR: Exactly. So here it is. So everything is coming up in a straight line because everything is rising. See the Moon. The Moon is just making a line up because it’s coming parallel to the equator which is exactly at the 90 degree angle from the horizon.

CB: Okay, got it. But for most other countries that are north or south of the equator, there’s more of an inclination basically, right?

LR: Exactly. Now let’s see the same thing. Let me stop this. And let’s see this way, way up north. So let me change the location again and let me place for example somewhere here.

CB: Norway, Denmark, Sweden.

LR: Yeah.

CB: Okay.

LR: As we can see, the inclination is quite different.

CB: Okay, so press play again. Let me see it move and what it looks like.

LR: Here it goes. See? Things are coming.

CB: Okay, so it’s–

LR: With a very low angle. They’re going to take a long time to rise.

CB: Got it. So it’s more sort of slanted instead of going straight up vertically?

LR: Exactly.

CB: All right. All right. So I think that makes sense more or less or at least gives people a general sense of that point.

LR: How it moves, yeah.

CB: Right. Okay. All right. So let’s go back.

LR: Here you see the ecliptic coming in, right? Because we have a very high latitude, this is going to be relevant. The ecliptic almost rose entirely at the same time. I’ll go back a bit so you can see. This is important because this is going to complicate the calculation of houses on higher latitudes. This is it. You see the ecliptic at one point here there are several degrees of the ecliptic rising. Oops, sorry. It’s not easy to control the speed. You see it coming there. And now it’s going to make a curve. So there are at least two points of the ecliptic rising at the same time. And this is where things start to be problematic because then you have degrees that rise simultaneously. This is a very high polar latitude. Degrees that rise simultaneously or certain parts of the ecliptic won’t rise at all especially in the poles. Yeah.

CB: Why? When you get super far north some of the different forms of house division either become very distorted or sort of break down entirely.

LR: Yeah, collapse entirely.

CB: Okay, so let’s go back to the presentation and see how we apply that or how some of those references work then in terms of the different forms of house division.

LR: Yeah. Okay, so we were talking about the equator and how the equator was differently slanted depending on your latitude as we just saw in Stellarium. And of course the ecliptic will be at a certain point, and this is a given point in time. It’s going to have that 23 1/2 degrees deviation from the equator. And then we can, here it is, Aries and Libra, the points zero Aries zero Libra, the points where the ecliptic and the equator intercept as we discussed before. And then the belt, the zodiacal belt which is the area where the planets move. So because they will not move exactly on top of the ecliptic, they can be a bit north, a bit south. That’s the zodiacal latitude. So you draw the zodiac as a belt to account for that slight difference that they can have from time to time.

CB: Okay. Right.

LR: Okay. Okay. So what we are going to do, and now we’re going finally to the explanation of house division is going. We’re taking our sweet time getting there.

CB: And also we’re only two hours and five minutes in the episode, so we’re making very good progress.

LR: Yeah, I think so, [laughs] taking into account the complexity. So, here we are. Now everything in one diagram. That’s why it’s difficult to represent here the spatial coordinates of the meridian, the prime vertical as well as the celestial references of the equator and the zodiac. And now what are we going to do? We’re going to slice this through the meridian because it’s easy to represent this in 2D. 3D will be complicated. So we’re going to have our observer the meridian and east. This is like we’re outside the universe and we’re looking at the east point. So here we have the meridian, south, north, east because we are looking from that position. And then we have, dividing this in half, the prime vertical. And it is from this that we divide things. Then we have the equator, let’s say, at the given latitude, the celestial equator. And then at the given point we have the ecliptic, the Ascendant, the Midheaven, and the IC, where the ecliptic intercepts the meridian. So, one. Okay, this is again the five-degree example of Taurus that I pulled up earlier. So how are we going to divide this? And this is the problem. So let’s begin. Oh, here’s zero Aries. And let’s go to whole sign. With whole sign, we’re doing a division, a structuring of the houses according to signs taking into account the ascending degree. So it’s quite a straightforward division. It wouldn’t need such a complex representation. Let’s consider the signs. Let’s consider the divisions between the poles of the ecliptic like the size where the signs were slices in an orange, 12 divided orange. And here we have–

CB: All you need to do is establish what the degree of the zodiac is that’s rising over the eastern horizon. And once you do that, then you can establish the entire house system for whole sign houses.

LR: Exactly, so here it is. The third house will be Cancer, the second would be Gemini, the first Taurus where the Ascendant is. The 12th will be Aries, the 11th Pisces, the 10th would be Aquarius. And we could see here still in the projection a little bit of the ninth. Because if you recall, the MC was at 20 degrees Capricorn which would be the whole sign ninth.

CB: Right, so I liked your analogy. It’s like slices of an orange basically, the whole sign approach. Since it uses the signs as the houses, they’re all exactly 30 degrees each.

LR: Yeah. Exactly.

CB: Okay, so that’s pretty straightforward. So that’s the whole sign.

LR: Yeah, that’s the whole sign. So here it is what we’re observing. And here we are. So we have five degrees of Taurus rising at the east, so the whole part of the house is five degrees up from the horizon because you’re considering the entire sign. If it was 29, almost the entirety of the sign would be above the horizon. And here we can see the discrepancy between the 90 degrees at zero Aquarius and then the meridian degree at 20 Capricorn.

CB: Right. So in this system since it’s anchored on the Ascendant and all of the houses are just measured relative to the Ascendant or relative to the rising sign, the Midheaven or the meridian just floats around the top half of the chart and becomes a degree or a sensitive point rather than the starting point for the 10th house because in whole sign houses the 10th house is always just the 10th sign relative to the rising sign?

LR: Exactly.

CB: Okay.

LR: Okay. Next one on our list, equal houses which sometimes in mathematical books is called the single longitude method. And this means that it’s only considered one longitude which is the Ascendant, not two and not the Midheaven again. But here it is different because let’s establish these small points are the signs, the position of the signs. So what this will do is consider the Ascendant, and it’s going to repeat the Ascendant degree with an increment of 30 degrees until it reaches again the ascending degree. So here all cusps will be at five degrees of the given signs or five Taurus, five Gemini, five Cancer, etc.

CB: Right, so once you’ve established the exact degree of the Ascendant. So whole sign, we just had to establish the sign that was rising. But with equal houses, we establish the degree of the Ascendant and then we measure out in 30-degree increments from there to establish the other house cusps.

LR: Yeah. So it’s going to be divided again through the north pole of the ecliptic. But instead of dividing through the exact divisions of the signs, you’re going to divide it by the degree of the ecliptic which is in this case in this example five degrees. And you have the houses again. Yeah, here we are. Again, you’ll have a little bit of the ninth house there. As we’re going to see in the diagram, all cusps are at five degrees. So in this case the difference between the beginning of the 10th house and the meridian, it’s a little larger than it was in the whole sign because of that five-degree offset.

CB: Right. So if the Ascendant is at five degrees of Taurus and equal houses, then the entire first house extends downwards until five Gemini. And then the second house is from five Gemini to five Cancer. And the third house is from five Cancer to five Leo. And it goes all the way until you get to the 10th house, and the cusp of the 10th house in equal houses is always exactly 90 degrees from the Ascendant degree upwards. And so that started the 10th houses from five Aquarius until five Pisces. And so this creates another situation where the degree of the meridian or the degree of the MC, as some would call it, will be a point that floats around the top part of the chart but does not necessarily act as the starting point for the 10th house. And so equal house’s actually where the nonagesimal degree comes into play. And that was one of the reasons why I was mentioning that earlier just because some proponents of equal houses will say that the nonagesimal which is 90 degrees from the Ascendant and because that’s the highest point of the ecliptic right there in this instance at five degrees of Aquarius, that might have some independent symbolic significance even if it is not the same as the meridian and it does not mark the exact north-south axis or the highest elevation of the planets, per se.

LR: Exactly, yeah.

CB: Okay.

LR: Okay. So with equal houses, it’s the last of the non-quadrant house systems that we’re going to see today. So the next one, it’s going to be what we call the porphyry and what is sometimes also known as the dual longitude method. And dual longitude because for the first time in this sequence, the system will consider both the Ascendant and the Midheaven degree as point of house cusps. So it considers two longitudes, the Ascendant and the Midheaven. What it does is the ecliptic it’s going to be divided in three, so the two arcs here that we see. The arc that is below the horizon and the arc above the horizon, it’s going to be divided in three equal parts. Here we are. And these three equal parts are the cusps of the houses. It is very straightforward. And then considering the poles of the ecliptic, here we have the houses. But in this case the cusp of the house, it coincides with the Midheaven also with the meridian with the degree of the ecliptic that is culminating in the meridian. And here we have three houses below the horizon, two and three above the horizon. And the cusp of the 10th is coincidental with the Midheaven. And here it is, what is perhaps the most simple of the quadrant systems.

CB: Right, so switching to the next one. Basically with this method this is the first of the quadrant systems. Once you establish the degree of the Ascendant and the degree of the meridian, you then break that up into four quadrants as they’re called. So it’s not just the degree of the Ascendant and the degree of the meridian but also the degree opposite the Ascendant which is the Descendant and then the degree opposite the meridian which is the IC or different names for it. We don’t really have any very good names for it, honestly. It’s the place under the ground is like the Greek word.

LR: The angle of Earth. I like the one angle of Earth.

CB: Angle of Earth, yeah, that’s pretty good. So then you take those four quadrants in between those four points and you divide them into three. And that’s what all of the different so-called quadrant house systems do. But this first one, the most simple one, porphyry houses just divides those distances into even thirds.

LR: Yeah, exactly. Divides straightforwardly the ecliptic and it’s done with. So it’s quite simple in that regard.

CB: Okay. In your example if the Ascendant is at five degrees of Taurus and the meridian Midheaven is at 20 degrees of Capricorn, then you calculate the number of degrees from five Taurus to 20 Capricorn. And then you divide that into thirds. And then you end up with the cusps of the, in this instance, 11th house and 12th house.

LR: Yeah, exactly. And in this system for the first time we see that there is the two houses that has the cusp in the same sign. For example, the second house begins at zero something within a few minutes of Gemini and the third house as well which is something that never occurs in the previous two systems.

CB: Right. So this is the first time we’ve seen. In whole sign and equal houses, the houses are always exactly 30 degrees in length. But in the quadrant systems, we introduce houses of varying and uneven sizes. And sometimes that can lead to the same sign containing two houses or however you wanna put that. But that’s the concept of interceptions, right?

LR: Yeah, yeah. And for example in this case Virgo and Pisces don’t have any cusp there although here we have a situation of zero degrees, but neither Pisces nor Virgo have a house cusp there. So these are called the so-called intercepted signs although I’m not sure if this concept exists in tradition. The idea that the sign can be contained within the house, yes, certainly. But not the term intercepted. I never seen it.

CB: Okay. And yeah, in terms of giving that some sort of special significance where sometimes in modern astrology like an intercepted house or sign as they try to come up with a rationale or a meaning to that. So that’s a really good point though just in terms of explaining and sometimes belaboring basics. Your point earlier was that here the second house begins at zero degrees of Gemini and then the third house begins at 25 Gemini. So we have in quadrant houses sometimes houses that begin with the same sign which is unique compared to the other two approaches. Or, as we’re just saying, we have some signs that are skipped completely such as the fifth house cusp starting at 25 Leo and the sixth house cusp starting at zero degrees of Libra which completely skips the sign of Virgo. So that would be one of the main distinctions between the quadrant house systems such as Porphyry and Placidus and other approaches versus the equal and quadrant house systems, where there’s always one sign and one house.

LR: Mhm. Exactly.

CB: Okay, cool.

LR: Okay. The next one is going to be Alcabitius which is a development, if you can call it that, from the Porphyry division, so from the dual longitude. So in this case now things get to become complicated, and the rationale that appears to be behind this is that Porphyry does not account for heavenly movement. So if we want to account for heavenly movement, what we’re going to do is to consider the arc of motion, that parallel arc of motion that the Ascendant degree is going to make throughout its diurnal path is 24 hours. So here we are going to track and plot a course parallel to the equator which is exactly the trajectory of that five degrees of Taurus throughout the 24-hour period. And instead of dividing the ecliptic, we’re going to divide this trajectory into 12 equal parts. So for example three parts for the quadrant above and three parts for the quadrant below the horizon. And then we have to projet these points onto the ecliptic. And how are we going to do that? We’re going to use the equator to mark this. So we’re going to take the North Pole celestial pole and the south, and we’re going to do these meridian lines. These are called meridian lines that are going to be parallel, let’s say, to the meridian. And we’re going to slice the orange but considering the North Pole of the equator and the South Pole of the equator which is where the axis of rotation is happening. So if you’re considering the movement of the Ascendant degree throughout the 24-hour period, you’re going to divide it through the axis to project it onto the ecliptic. And where these projections intercept the ecliptic, you’re going to find the house cusps which are going to be those circles in the ecliptic.

CB: Okay, so the Alcabitius method incorporates the degree of the Ascendant and the degree of the meridian. And then in order to determine the intermediate house cusps, it incorporates the celestial equator into the mix or into the equation.

LR: Exactly. So it accounts for the motion of the degree of the Ascendant in relationship to the equator, and then it’s going to establish these slices of houses which are related to the equator because we are tracking the motion. And the motion is always done parallel to the equator through the equator’s motion. And I think it is the ability of this system to combine the quadrants and the motion that perhaps was so attractive to practitioners. It is a supposition. We don’t have anyone stating this, but it’s a supposition.

CB: Sure. And in terms of the level of complexity, it’s not quite as simple, it’s a step up obviously from Porphyry where you’re just dividing the quadrants into thirds. But it’s also not super super complex mathematically at this point, it’s still somewhat doable, right?

LR: Exactly.

CB: Okay. So how does that look on a chart?

LR: Here it is. It’s not going to look terribly different from the previous one, as you could see. Again, we have the second house cusp and the third house cusp beginning in Gemini. But they’re off a few degrees from the other position of Porphyry.

CB: Right. So the degree of the Ascendant, the Descendant, the Midheaven or 10th house cusp, and the IC are still the same. But then what’s changed is the other intermediate cusps have shifted slightly. And so I can see for example, I think the fifth house cusp used to be at 25 Leo in Porphyry, and that’s shifted over to, I think, 23 Leo here. Or the sixth house cusp was at zero degrees of Libra in Porphyry, but now it’s shifted to 29 degrees of Virgo here. So just a degree off, but it moved into a different sign which for astrologers would be a major shift because it would change the rulers of the houses from a Venus-ruled sign of Libra to a Mercury-ruled sign of Virgo.

LR: Yeah. Yeah. Yeah, so the interpretation would be completely different.

CB: Yeah, so a completely different interpretation. And so this is entirely based on just how the quadrants were divided and incorporating a different astronomical reference point in order to measure them relative to and that therefore changing or subtly shifting the house cusps.

LR: Yeah, exactly.

CB: Cool. Okay.

LR: Okay, next on line. We have Campanus, so the prime vertical method. And this name explains what it’s doing. It’s the prime vertical method because it’s very simple method with which we get the prime vertical, divide the prime vertical into 12 parts. We will just see the six of this half. And then you simply use the poles to divide it. See? Simple division of the prime vertical. So that there is a greater circle that goes from east to zenith to west and then nadir and east again. That one is divided into 12 equal parts accounting the meridian and the horizons to the Ascendant. And then you just slice it up into 12, and you have these houses like this. This was a very ingenious and it was always considered by authors who described as very ingenious because it’s dividing space. It’s dividing your local space of observation into 12. So it’s very intuitive in terms of perception what is the house. So that’s probably  is it’s attractive, it’s appeal. It’s this. It’s not as easy to compute as Alcabitius, it’s much more complex because now you have to have a different referential that is the prime vertical, and you have to transform these coordinates of the prime vertical into the ecliptic. And this is a bit complicated. And as you can see here in the diagram, I placed the equator which is the blue line slightly transparent because the equator is not considered at all in this division. So there is no movement here of degrees being taken into account.

CB: So in the previous method, in the Alcabitius method, the equator was the primary thing or one of the primary things that was taken into account in terms of determining the house cusps. But in this we’re focused more in the Campanus method on the prime vertical and on the directionality of north and south and using that to calculate the house cusps.

LR: Yeah, yeah. It’s a simple division of space into 12 parts. Yeah.

CB: Okay. So how does that look? Let’s see how that looks on a chart and how it divides the cusps differently.

LR: Well, here we go. So yeah. [laughs]

CB: Okay, we got a major shift at this point in terms of the intermediate house cusps. So the Ascendant, Descendant, Midheaven, and IC are still the same. But now there’s been a major shift in terms of the intermediate houses such as the second and third and the fourth and fifth which suddenly things are becoming a lot less sort of evenly distributed and a lot less proportional in some sense. So the second house cusp now is at 15 degrees of Gemini, and the third house cusp is at five Cancer. And the fifth house cusp is at seven Leo, and the sixth house cusp is at eight Virgo. So that’s a pretty major shift from I think in the previous one in Alcabitius the fifth house cusp was at 23 Leo, so it jumped all the way to seven. And the sixth house cusp was at 29 Virgo, and that’s jumped all the way to eight Virgo at this point. So that’s a pretty huge shift.

LR: Yeah. And this kind of configuration is typical of Campanus. You almost can identify a Campanus chart when you see this. So the 10th and the ninth as well as the third and the fourth are very small and usually have a huge 12 house, a huge first house, and as well a seventh and a sixth. That’s usually the case. There is a big big difference in terms of division.

CB: Yeah. Okay. So now we start to see how some of these different astronomical reference points that can be taken into account in the computation of houses, how sometimes they can lead to just radically different results versus in others sometimes the results are a little bit more subtle or a little bit more muted.

LR: Yeah. Yeah. And we’re always dividing something by 12 equal parts. [laughs]

CB: Right. But it turns out there’s many different ways to divide something into 12 parts.

LR: Yeah, yeah, yeah. And the problem is when we project these divisions into the ecliptic, this kind of difference, such a big difference can be observed in the zodiac. So let’s take a look at the next one which is Regiomontanus also called the rational method or the equitorial method. And the equitorial method is what mathematicians call it because exactly what it’s going to do is instead of dividing the prime vertical, it’s going to divide the celestial equator into 12 equal parts. And the rationale at least in Regiomontanus’ own words is that it now is considering the motion of the heavens centered on the equator while Campanus is not. It’s a still system. So what he does is he divides the system, divides the equator into 12 equal parts and then makes the projection still within the local space in the same manner as the Campanus does. So instead of dividing the prime vertical, it divides the equator. And then it projects again to a north, south lines which will yield a different result. The houses are again very similar. The two systems are very similar in terms of diagram, but the results will be much different.

CB: Because both read Regiomontanus and Alcabitius are focused on the celestial equator?

LR: No. They always slice the space according to the prime vertical. That’s what they have in common. But Campanus divides the prime vertical directly while Regiomontanus divides the equator.

CB: Okay.

LR: And, again, the difference is it yields a similar result to Campanus. But the size of the houses, it’s not as pronounced. It distributes the size a little bit more evenly than before.

CB: Okay, so it’s not quite as distorted or clustered with some of the houses as the previous system as the Campanus method. But there’s still definitely much more of a discrepancy in this method, Regiomontanus, compared to the first two quadrant systems we looked at which were Porphyry and Alcabitius, where the cusps were relatively close to each other. So here the second house cusp is at nine degrees of Gemini, and the third house cusp is at one Cancer, and then the fifth house cusp is at 12 Leo, and the sixth house cusp is at 17 degrees of Virgo.

LR: Mhm. Yeah. So not as pronounced as before but still more or less along the same lines. And this method was very, very popular due to the name, the rational method, because it was this combination of the movement of the equator with the local space of the prime vertical was seen as genial, as a very good idea in terms of how to divide celestial movement and how to divide celestial space.

CB: Yeah, some of these names sound a little bit like sometimes politicians in the US will name bills that they want to get passed after positive concepts like patriotism like the Patriot Act or something like that in order to raise support for it. I feel like that might be a common thread here with some of these house division names is that if you wanna promote a form of house division, you have to give it a good name to it like the rational method or the super cool house division system or something like that. [laughs]

LR: Exactly, exactly. A good naming is everything. [laughs]

CB: Right, naming is everything. Okay.

LR: Apparently.

CB: So we’ll have to think about some different names for the different systems that would be good keywords to promote them.

LR: Mhm. Yeah. Okay. And finally the last one we are speaking today is Placidus, so the traditional one. Placidus although it has some resemblances to Alcabitius, it’s not quite the same thing. This is a good time perhaps before we proceed to talk about that idea that runs all over the astrology nowadays which is this idea of space, of systems that divide space and systems that divide time. And although we can understand why they are divided like this and Alcabitius would be a time system because it accounts for the time that the degree of the Ascendant turns around to the Midheaven, etc. And Regiomontanus and Campanus beat space because they’re dividing space. We have to also perceive that space and time here are sort of the same thing. They’re all dividing space, as we’ve seen. They’re slicing space up in different ways. So they’re all spatial in that regard, and they all account time in one way or the other and equitorial coordinates. So if you want to measure something on the equator, these can be measured in degrees or in hours. So zero degrees of the equator is also zero hours. So time and space here it’s a bit different. It’s not that straightforward as it seems. Well, in Placidus it’s called the hour line method. And I think that’s the name that explains what it is. Because it’s going to use the hour lines to divide the houses. So how is this accomplished?The hours are measured by the equator. Because the equator is the one that is moving and constantly going out of time. So if we divide the equator into 24 equal parts, we’ll have each of these parts will be an hour. As we can see here in the diagram you have from the 19th hour to the 24th hour being right before the rising. And then after the rising, after the horizon, we have the first hour, the second hour, up to the sixth before hitting the meridian which would be the beginning of the seventh hour of the day. So the hours are measured of course according to the movement of the Sun, and these are solar hours or the so-called unequal hours because these are measured by the amount of time the Sun is above the horizon or below the horizon. So the hours that you would obtain by using a sundial and not the hours that we obtain by using a watch which divides all of this equally, independently of the movement of the heavens.

CB: Right. That’s one of the cool things about Placidus then that makes it unique is it’s sort of very loosely kind of related to the planetary days and planetary hours system as well, right?

LR: Mhm. Yeah, exactly.

CB: Okay.

LR: It follows the same principle of division of time. So how do we represent this in space? So we have to now take account two other things that I didn’t mention here which is the Tropic of Cancer and the Tropic of Capricorn or its projection in the heavens. So the Tropic of Cancer here, this line of Cancer, is simply if you place the zero degree of Cancer and stress its diurnal motion parallel to the equator, you’d get this line because it’s the northernmost degree of the ecliptic. And the Tropic of Capricorn represents the southernmost degree of the ecliptic which is zero degrees of Capricorn. So these are our two extremes of the ecliptic, where the Sun is going to reach. The Sun doesn’t go higher than these two points. When we divide this here, we’re going to see that there is a difference. So in the Tropic of Cancer, the hours of the day are larger than the hours of the night because this will be the summer in the Northern Hemisphere. So you have a much more quantity of hours of day during that period. It’s a maximum of daylight.

CB: So if you’re measuring the hours of day that’s going to shift based on the seasons because during some seasons, the hours of daylight are much longer and during some, they’re much shorter.

LR: Exactly. And the opposite will occur for Capricorn. The night hours are going to be larger than the day hours because we’re on the peak of winter where the Sun doesn’t rise so much towards the horizon and the daylight hours are much, much less. And so to project the hours in space, we do these lines connecting the equal division in the center with the extremes of the division in the northernmost and southernmost part of the cycle of time. We have these dotted orange lines which are called the hour lines. Each one corresponds to one in an equal hour which has different times, different durations in relationship to the equator. And so what this system does is it accounts every two hours to a house. So every two hours corresponds to a house and these segments will be the houses.

CB: Okay, so this is taking into account just a completely different reference framework which is the hours of sunlight during a day that’s divided over the course of the day and then connecting that up as the cusps of the houses and each house is basically two of these hours?

LR: Yeah, exactly. It’s simple. Once you understand it, it’s quite simple. Mathematically, this is an absolute nightmare.

CB: So, this is the most complicated system so far?

LR: Yeah, this is very complicated because none of the hour lines are greater circles so they do not divide the sphere into parts. They are not complete circles. These are just lines. They’re not circles. And that makes the computation quite complex. There was a time where the mathematics was not developed enough to be able to compute this in an easier way. It was only with Placidus later on that this mathematic was already sophisticated enough to be computed with precision, and probably that accounts for the late appearance of the system in practice.

CB: And once it can be computed though, it ended up eventually just printed in tables of houses where astrologers when they were going to calculate a chart would just look it up in pre-calculated tables basically which would simplify the actual calculation when you’re trying to do this in a chart. And one of James Holden’s statements that he makes is like an offhand comment about why he thought Placidus became the common method in the 20th century is because it was one of the only ones where tables of houses stayed in circulation because it had taken off during earlier generations. Yeah. So, it’s not that each astrologer would have to do all of the complex mathematics underlying this in order to calculate it, but once it was established and there were tables available, it could be applied somewhat more easily.

LR: Yeah, you don’t have to do it from scratch. You don’t have to do it from zero grounds, so it makes it easier. And the same phenomena happened with Regiomontanus. There was also the idea that Regiomontanus gained the popularity that it gained because the tables were readily available. Of course, this can always be argued that it’s not just the tables, but it’s also the logic behind it. And not entering into a very complex discussion, the fact that Regiomontanus had together with it also a system of primary directions which would emulate the same movement of the houses to calculate the directions and Placidus as well, these make them complete packages which were very appealing to a mathematical mind. The same system calculates two different things in the same manner and this also has to do with the appeal. This was something I was discussing a few days ago with Martin Gansten who’s more of an expert in primary direction calculation than I am, but this combination of the two systems in the same method is going to give a uniformity that is quite, quite appealing.

CB: Yeah. Well, that’s a really good point that many of the discussions especially about the different forms of house division, but also the quadrant systems of house division were tied up in discussions about primary directions and at least very early on, that discussion was often tied up in the length of life treatment which was like one of the most important techniques for traditional astrologers or older astrologers because it was like the main thing that everyone sought to be able to achieve. The most important technique that you could possibly pull off as an astrologer is knowing the length of a person’s life. And in Ptolemy, he said, it was the most important technique that you should apply first because you shouldn’t predict great things for somebody that’s not going to live long enough to see them. But in Valens and Ptolemy and some of the other Hellenistic authors, it was always during the course of the length of life technique that they would first introduce and start talking about the different forms of house division and introduce the degree-based systems like Porphyry is introduced at this point in Valens in Book Three or Ptolemy supposedly introduces equal houses and so on and so forth.

LR: Yeah. And this is the point where it seems interesting, this connection, because although technically you do not need to account directions with the house system you use, there’s no rule that says that has to be done so although some authors claim that they should be done the same way because of this connection that you just mentioned. It also hints that the development of a quadrant system has exactly to do with this calculation of the directions because to calculate the directions precisely, you need to account the celestial movement according to the equator and so the combination will hit in the meridian. And so, once you’re calculating the directions in this manner, so having to account the meridian and the movement parallel to the celestial equator, it would be expectable that why aren’t we doing the same thing with the houses because we’re dividing the space. There is a connection, definitely a connection here behind the reasoning that leads to the appearance of a quadrant house division. It has to do with this method of directions which is one of those that perhaps together with profections is resilient in the tradition. It transverses tradition throughout time from antiquity to the early modern period, and they’re always applying at least directions and progressions and then later on the solar revolutions as well as being the three main methods for prediction. But directions and profections I think are two of the oldest which makes them quite an important point in this regard. I think that the mathematical complexity required for directions is also connected to the mathematical complexities of the house systems. And you see that for example, in astrolabes, some of the astrolabes which we’ll talk in a minute are going to be made so, not all of them, these are more complex ones, have divisions so that you can calculate the directions directly on the astrolabe, so facilitating a lot the time you need to calculate all these motions. Yeah.

CB: Yeah. And what I argued in my book and in episode 227 of The Astrology Podcast was I think that we had these three early texts, we had the Hermes text which introduced I think the original proposal about the concept of the 12 houses and it introduced a very basic set of significations for each of the 12 houses of like seventh house equals the marriage partner and 10th house indicates career. In that system, they used whole sign houses or introduced the concept of whole sign houses. Then you had the Asclepius text which came afterwards and this introduced some additional significations of the houses, and it also introduced the concept of equal houses and dividing from the degree of the Ascendant. But it’s that system that introduced certain topics that became common like associating the fifth house with children or the eighth house with death actually came from the Asclepius text. So a lot of the later astrologers merged and synthesize those two texts in the later traditions of house associations. But then sometime after those two, there was this other very important and influential compendium that was attributed to these mythical Egyptian figures named Nechepso and Petosiris. And in this text, it seems to have introduced the original idea for the length of life technique because a lot of astrologers like Ptolemy and Valens and Manetho will cite this text and they’ll always start talking about Petosiris or Nechepso when they start talking about the length of life treatment or they’ll sometimes refer to them mysteriously as the ancient ones. But it was this text I think that introduced the length of life treatment that used primary directions to direct planets towards each other or to progress them towards each other until a planet would hit the ray of the malefic like a hard aspect with the malefic and that would indicate either a major negative event for health or potentially the end of the person’s life. But this text seems to have described some form of quadrant house division or some form of degree-based division that was not whole sign houses and I think this is the reason why a lot of the Hellenistic astrologers at this point start outlining these different forms of quadrant house division or as in the case of Ptolemy, maybe equal house division, it’s because they’re all emulating something that was described somewhat mysteriously or in a way that was unclear in this text but it was very much wrapped up in this technique for the length of life treatment. And that’s part of what led to so much confusion in subsequent traditions because it must not have been very definitive about exactly what approach you should use, but instead I think it used some vague directional language about north and south and east and west that may have implied that you were supposed to use a degree-based system of house division, but it may have not have come down very clearly on which one you should use.

LR: Yeah, and that is typical of astrological text. They hint what might be degree basis or not, but then you would need the mathematical equivalent where the calculation is explained to really understand what exactly are they doing, and that’s our problem. We always have a partial view and this seems to be a constant in history. It is the mathematical books, the tables usually that have the form of calculation and allow the identification of exactly what they are defining. And unfortunately, very rarely, the astrological books have this kind of description which leaves us with this kind of doubt. Is it saying this? Is it not? There’s always a lingering doubt of what exactly do they mean and that’s why you have a number of houses of what exactly Ptolemy was meant to say, but yeah.

CB: That’s what I was just thinking about was Ptolemy [laughs] because Ptolemy is probably drawing on this earlier mysterious text from Petosiris and Nechepso where it’s not really clear and Ptolemy outlines some degree-based form of house division in his length of life chapter in Book Three of the Tetrabiblos. But then immediately within the first few centuries of Ptolemy, if you read the Hephaistio of Thebes who wrote in the fifth century, he says, one person interprets Ptolemy this way to outline basically equal houses and that’s what Ptolemy intended. But then he cites another author who says that no, Ptolemy really meant this quadrant system and outlines a quadrant system of house divisions. So, already in the first few centuries, there’s a lot of controversy just based on trying to interpret what Ptolemy meant and some astrologers read between the lines of what they think he meant and come up with new systems or new approaches.

LR: Yeah, yeah. And the Arabs going to continue this arguing the mathematical logic and dividing one thing or the other. Is it sound? Does it make sense? There’s a lot of debate, mathematic debate. Even later on, for example, there is this debate of early modern authors. I’m not sure exactly who because I’ve seen this reference elsewhere, I haven’t seen it directly. In which they’re explaining astrology towards natural philosophy so there’s the cause and effect, etc. So that question is very, very interesting and reveals a little bit about the debates that are going on. And they say this, if planets change their significance depending on the angle that they have from the horizon. So, it’s as a planet rises, that gets more powerful or it has a different incidence of its rays, so it’s going to have a different meaning. If that’s how the house system works, then we should divide the planetary motion and you should have systems like Alcabitius or perhaps Placidus. But if you consider that the houses are areas of the heavens which have in themselves meaning and that as the planet transverse that area acquires that specific topic or that specific meaning, then a division such as Campanus or Regiomontanus makes more sense. And this is a very interesting debate because it might not work at all like this, but it’s interesting to see how they are trying to choose one or the other based on how they explain the very function of astrology. And this is sometimes a debate that unfortunately doesn’t survive in the texts and perhaps could clarify why are they making certain choices in division and not others. But it’s interesting. There’s a very substantial conversation going on in the astrological milieu of how do you do this better?

CB: Right. And all of the different things that are motivating it which are sometimes wildly different. Like you’re saying, sometimes we’re talking about like with Ptolemy, there’s textual reason so astrologers have textual arguments for the sources that they’re drawing on and that’s why they prefer one system or another or that’s why they are introducing different systems based on almost like philological arguments about what they think the ancients did or whatever relative to their time period the ancient authors or the main authorities were. It’s almost like more of a historical argument. Or other times, we have people who are actual astronomers that are trying to come up with conceptual or astronomical reasons for why you should use one system or another because they think different reference points are more important or should be taken into account or given more weight versus other reference points like the prime vertical or the celestial equator or what have you as we’ve gone through in some of these systems. And then finally, there’s a whole other category which is just once you’ve done the astronomy and astronomy aside, once you project that onto a chart, just where do the house cusps fall and sometimes just different astrologers deciding they like one system or another based on how it works in their chart based on where a house cusp falls and what house that puts certain planets in their chart versus this other system moves it to this different house which they don’t think works as much and so they base it more on that more practical or subjective or empirical or whatever you want to call it sort of approach to things.

LR: Yeah, yeah, exactly. There is these various layers of debates and various points of view which the debate is taking place and it’s very interesting. And now I think at one point, a larger research project should be made to really substantiate the information that we have nowadays which is already a lot, but we need more and perhaps a research project will be good. For example, the number of charts, there’s no sensors of the charts that carry one system or another. For example, it’s not that I’ve seen a lot of manuscripts. I’ve never came across in the early modern chart with the Campanus system and we know that it was used and there was debate surrounding it. I’ve never seen an example of it. Regiomontanus there’s a lot, Alcabitius tons, but the other systems are not so represented at this period, so it would be interesting to understand exactly what is the representativity in practice of these systems. Another thing that is curious is that sometimes astrologers propose system or create one like Al-Biruni and then appear to use another one in their practice. Al-Biruni is often quoted as the self-proclaimed inventor of what we call the Campanus system, but according to some authors, when he draws his own chart, he does it with the Alcabitius system, with the standard system of his time. So then we are left with a question. Okay, so is that just a theory, a mathematical exercise or has it to do with its practice? Another thing that happens is that sometimes we see other systems in the tradition that we didn’t discuss here because they just appear in one or two authors which appear to be only discussed as a mathematical comparison, you know? You’re explaining, for example, how you do a Campanus division and then you say, well, let’s imagine that instead of this, we would divide something else or we would slice this in another way and then suddenly a new house system appears. That from what we understand, it’s just a mathematical exemplification of how we would do such a calculation. It’s not intended for practical use. And this is interesting as well, you know? It’s just thinking mathematics and doing an exercise, so let’s make up a house system and see how we would solve it mathematically. But you’re not going to use it because it’s just coming out the top of your head. We have to account for all these variances in our sources. Yeah.

CB: Right. Yeah, that’s really good point. And some systems being maybe developed more as like a theoretical exercise rather than something that was used in practice or yeah, having a better documentation of all of the charts that survive in history so that you could have like a graph or a distribution would be really useful. I tried to do that in my book for the Hellenistic tradition just in order to make the point about defending the point against some criticisms when I would say that whole sign houses was the predominant form of house division. In the Hellenistic tradition, I wanted to be able to validate that by having like actual numbers and graphs, so I like went through and counted up every chart that was used in Valens or every chart that was in Neugebauer‘s Greek Horoscopes and then tabulated them. But it would be nice to see something like that for the Medieval tradition or the Renaissance tradition or what have you.

LR: Yeah. And perhaps we could see regional differences which I’m certain that they exist.

CB: Yeah. Even during the Hellenistic tradition, you see a huge uptake in quadrant systems by the fifth century by the time you get to Rhetorius and some of those authors compared to earlier. Yeah, so that would be very interesting. Also sometimes there’s issues when it comes to different people approaching this and sometimes having a blind spot or a bias or what have you. Sometimes, for example, we talked about earlier different academics who have written on this and I’ve been somewhat critical of like JD North, for example, by not recognizing whole sign houses as a concept or not seeming to be aware of it where I wonder sometimes if some academics because they’re not practitioners, they might approach things in a certain way or with certain blind spots that might be different versus how a practitioner what they might see when they’re reading the texts and sometimes that can be a drawback or that can be a downside to not having that practitioner’s eye for things. But on the other hand, then with astrologers who sometimes approach this as an issue with the history of astrology of what were the different forms of house division or what was the oldest system of house division, sometimes because they’re practitioners, they can see things in older texts that an academic might not. But then also, sometimes astrologers bring their own baggage or preferences or different things to it that might be a bias towards different systems and sometimes that can skew their interpretation of the texts in different ways, which also can be a drawback sometimes as well.

LR: Yeah, that’s always a problem with academic research. You always have some bias on your own perspective and you need to be very, very attentive of that so that you’re recounting the facts and not shifting them on your own perspective. Yeah, that’s always very important. That’s why peer reviewing is so important because then someone looking at your work from the outside can say, “Well, but this is not clear here. This correlation is not well established,” and that’s a good thing. That’s something that we lack a lot in astrology. What I’ve also observed because I was doing some research for this conversation we’re having is that there are a lot of errors not only in the historical description but also sometimes in the mathematical description of house systems throughout the internet. If you look for a system, sometimes there are discrepancies and errors in the description which clearly means that whoever did that was copying from somewhere else which was mistaken. It’s complicated. So, we have to be very weary of how systems are explained because sometimes there are very grave errors in them and a lot of confusion.

CB: Yeah, confusion seems to be one of the biggest reoccurring. I have this theory that whenever the concept of houses was introduced, there was some kind of astrological alignment or signature that just indicated confusion and murkiness because it seems like one of the most murky issues in the history of astrology. And even in the Hellenistic tradition, there was a murkiness about the fundamental terminology because sometimes when a Hellenistic or Greek author will say Ascendant, sometimes they mean the rising degree and sometimes they mean the entire rising sign. Or one of the issues with the Hellenistic texts is sometimes when they say Midheaven or mahzarnama  in Greek, it can mean three different things. Sometimes it means the culminating sign, the 10th sign relative to the Midheaven. Other times it can mean the nonagesimal degree or the 90 degree point relative to the Midheaven or relative to the Ascendant. And in other times, it can mean the meridian, the degree of the meridian or degree of the MC. So that means they’re using the same word and it can mean three entirely different things just based on the context or based on the author and their time period and what they intended to say.

LR: Yeah, exactly. Like, for example, nowadays perhaps not so common, but it’s very common to call the Midheaven the zenith, we were discussing this earlier on, when it’s not the zenith. You can say it’s a projection of the zenith in the ecliptic through the meridian, but it’s not the zenith point. That becomes complicated also because it’s misleading the understanding of the house systems. Yeah, it’s complex. It’s very complex. The language is very complex. And sometimes the way you state certain things can [laughs] make a huge mark in history for not understanding a certain concept or understanding it in a certain way which perhaps was not the one you intended in the first place. Yeah, yeah, it’s a huge problem how you write things and state things the most correctly possible.

CB: Yeah. I don’t know if you’re like me, but reading ancient texts and seeing how so many debates have been sparked by different interpretations of like a single sentence or stuff or something like that, it sometimes made me hyper aware of my own writing or statements and trying to be as clear as I can but sometimes, staying up at night wondering if somebody in two or 500 years is going to misinterpret some statement that I made in my book or some offhand comment in a podcast and it’s going to generate like an entire new tradition of astrology for like the next thousand years. [laughs]

LR: Yeah. Helena and I were very careful when we were writing On the Heavenly Spheres exactly because of that. Everything was state as clearly as we could quote so it wouldn’t have a second reading or misreading of any sorts. And it’s complex. It’s difficult. [laughs] It’s quite difficult.

CB: Yeah, yeah. Yeah, if Ptolemy only knew how many different traditions were generated from different interpretations of his text, I wonder what he would think. All right. Well, so this was pretty comprehensive. We’re at like three hours and 11 minutes. We were originally going to do a whole section on the astrolabe. At this point, I don’t know if we should try to squeeze it in or if we should save that for another time. What do you think?

LR: Well, if you want to do it, we can still do it. Very short introduction to the astrolabe. And if you see it’s too much, you can always divide this in two parts. [laughs]

CB: Yeah. All right. Let’s go ahead and do it then. Let’s just do a quick introduction to the astrolabe as an–

LR: As it relates to house system because the astrolabe in itself would require a lot more explanation than we can do here. Oh, yes, we forgot about Placidus. We didn’t show when it’s projected, exactly. Here it is. It’s similar somehow to Regiomontanus and Campanus in the sense that the upper houses are a little shorter than the houses near the horizon. But still the discrepancy is a little less pronounced than in Campanus in terms of the projection.

CB: Okay. So, the second house cusp is at 5 Gemini, the third house cusp is at 28 Gemini, the fifth house cusp is at 14 Leo, and the sixth house cusp at 18 degree of Virgo.

LR: Uh-huh, yeah. Okay. And perhaps now we can show the whole systems, the different cusps as we go. Here we have very quickly whole sign, then the shift to equal house, then Porphyry which becomes a quadrant, then Alcabitius, Campanus which is quite noticeable, Regiomontanus and then Placidus. Yeah, you can see the shift, the animation between these house systems.

CB: Yeah, sometimes very subtle and other times very major differences between them.

LR: Yeah, exactly, exactly. And these will be more pronounced if you have a higher latitude. So, as you approach that point where the houses are no longer able to be calculated because of the distortions of the ecliptic at those latitudes, then these differences will be much more pronounced. Yeah, in the quadrant systems. Okay. Let’s go to the astrolabe. Some astrolabe basics, and I’m going to do this quickly and if at one time [laughs] we need, we can do another one with more comprehensive.

Okay, here’s the astrolabe. The astrolabe has different parts which I will explain. It has first these basics which is called the matter, so the mother. There’s the base, the physical base of the astrolabe. Then in this mother, we’re going to put the plate and the plate is where the sky is represented for a given latitude. For example, this is drawn for the latitude of Lisbon 39 degree.

CB: Okay. The plate in astrolabe it’s like a usually a metal device although it could be made of other materials like wood, but it is made for a specific geographical location and a specific city and latitude basically?

LR: Exactly. And these plates, you can have several. So, most of the times after they happen, they have an Astro set of plates for different latitudes that probably were customized. You would buy an Astro when you ask for a plate from, I don’t know the latitude of 32 to the latitude of 34, for example, which were the areas where you operated or most of the charts you calculated were from those regions. That can be customized as you need.

CB: Right, like a difference between like one set for Baghdad versus Alexandria?

LR: Yeah, exactly. Here we have this the representation of the heaven. All of this is the representation of the heaven. Here we have the horizon. Here the meridian. We have the basic divisions. The celestial equator is represented by the circle. The outer circle is the Tropic of Capricorn, so the southernmost latitude of the ecliptic and the Tropic of Cancer, the northernmost latitude of the ecliptic. East is here, west and south because this is a northern hemisphere astrolabe. This is what we were seeing almost in 3D with Stellarium just pressed here into a plate. Then these markers here are the hour lines that we saw when we were talking about the Placidus divisions. It’s where you’re going to count time with the astrolabe because the astrolabe serves not only for astronomical purposes, but for a lot of things. Set telling time and for example, calculating the height of a building, for example, through its shadow. There’s a lot of applications for the astrolabe.

CB: All right. I read a paper that said like crazy high number of things you could do with an astrolabe and it was like 50 different things or 100 different applications that you could do with an astrolabe.

LR: Yeah, it’s a computation device, very complex one. And here what you have in this grid above the horizon is you have the zenith and then all of these are altitudes from 90 degrees in the zenith until you have 0 degree in the horizon, so it’s easy to measure the height of a celestial object. Oh yes, here is what we were observing there, but projected on that same scheme that we have been seeing with houses. This is what we have in the astrolabe. There’s heights from the horizon, the tropics, the hour line, and you’re observing this as you were seeing it from the celestial pole and then you just flatten a globe into that plate. Okay. The ecliptic is then represented here. But the ecliptic is a movable thing, so the ecliptic can be in a number of places regarding the horizon as the Earth moves. The ecliptic is going to be represented by this other piece, the rete which is movable. It can be moved through a screw in the center and represents of course, the zodiac and the ecliptic.

CB: Okay, so there’s another layer that shows the 12 signs of the zodiac?

LR: Exactly. And then you have these pointy things that can be represented and sometimes very beautifully in astrolabes which are stars of known longitudes. This rete is made for a specific date, taking into account the precession of the equinox, so it’s for a given date. As the time goes by, the asteroid no longer works with the stars because the precession has moved them further from these positions. Here we are. Now, how does this work? Yes. And then we have the pointer which is a ruler that you use to adjust your observations. A very simple way of doing things, for example, calculating an Ascendant is if in the daytime you have to measure the height of the Sun which is actually done not with this ruler, but with the backside, so this will be what we see here and we will do this with the other side of the astrolabe and this pointer that we would point at the Sun and measure its height through the shadow.

CB: Okay. So, you’d hold the device by like a string and then you would take the pointer on the back and point it towards the Sun and then that will tell you the altitude of the Sun?

LR: Exactly, that’s the idea here. But the principle is this one, so you measure the height of the Sun and then what you’re going to do is you know for example that today the Sun is at 4 degree of Leo because you can have a calendar with the degree of the Sun or the approximate degree.

CB: Like in an ephemeris if youknow from the ephemeris.

LR: Exactly, yeah. And Sun is very regular so it’s easy to do it. What you do is you get the height that you measured and you move the degree of the Sun to that height and there you have it. Where the ruler of the zodiac intercepts the curve, the horizon and the meridian, you have the Ascendant and the Midheaven.

CB: So right there it just tells you right away what degree the Ascendant is located at which is what degree of the zodiac is rising over the eastern horizon and then it also tells you the degree of the Midheaven at that moment.

LR: Yeah, the degree that is culminating, and that’s straightforward. It’s from here that you calculate the houses then. If you’re working at night, you would use a star. This is much more difficult in practice, but let’s say Arcturus, which is that pointy one there, and let’s say that you observe in the sky and you understood that Arcturus was culminating. What you have to do is to move that pointer where Arcturus is positioned to the meridian line like there and where you have the intersection of the zodiac in the meridian and the horizon, you have the degrees that are ascending at that point.

CB: Okay, so that’s what the fixed star positions are for is that at night when you don’t have the Sun, you can use the fixed stars to determine the rising degree and the Midheaven or culminating degree?

LR: Or time even if you use it another way. There’s a lot of usefulness with the astrolabe. The only thing that the astrolabe doesn’t do is to calculate planetary positions. Those you would need tables or direct observation. Okay. This is just to very straightforwardly see how easy it is to calculate the Ascendant and the Midheaven degrees in an astrolabe. It’s very, very straightforward.

CB: Right. So that’s super important and this is how especially by the Medieval period astrologers would have calculated the Ascendant and Midheaven very easily especially for the chart of the moment like a horary chart for example or an electional chart.

LR: Yeah, exactly, exactly. It’s easiest telling the time, you know? It’s very straightforward. Okay. Let’s see how the houses are calculated. Now, once you have established the degree, how do you move the houses? Let’s consider for example again, we have our astrolabe, let’s amplify it a lot and let’s see Alcabitius. How would you do it? Taking into account so again, we have the horizon, the meridian and the hour lines and as we saw, Alcabitius has to do with the time of the Ascendant degree, so we’re going to measure its time. We’re going to place the rete on the 5 degrees of Taurus that we have been using as an example. Once you put 5 degrees of Taurus for this latitude, you immediately calculate the angles. That is straightforward.

CB: Right. So we’ve calculated the Ascendant and the Midheaven using the astrolabe?

LR: Yeah. For example, the question was, what degree will be culminating when at this latitude? You just put the Ascendant of the moment 5 degree Taurus and immediately the astrolabe gives you all the other positions. And very easy you have the angles and the quadrant angles very, very easily.

CB: Right. The question is once you’ve established the Ascendant and the Midheaven, can the astrolabe also help you calculate the intermediate house cusps?

LR: Exactly. And Alcabitius is very easy. Alcabitius is a constant, so every manual on the astrolabe teaches you how to calculate the houses by the Alcabitius. What you do is taking the Ascendant degree, you make it so that the Ascendant degree is two hours. Each of these lines is one hour, so it is two hours apart. And two hours apart from 5 degrees of Taurus, you will find the cusp of the second house.

CB: Okay, so you can use the hour lines that are commonly inscribed on the astrolabe in order to calculate the Alcabitius house cusps, basically? It’s just a very trivial additional step to calculate those house cusps based on the hour lines.

LR: Exactly. For the third house cusp, it’s going to be two hours, so four hours apart, so extra two hours. You distance the degree of the Ascendant four hours from the meridian because the straight line is easier to read and you get the cusp of the third house. Then, because you only have the night portion of the astrolabe with the hour lines because if you projected hour lines on top of those you have there, it would be an absolute nightmare to read. What you do is for the other cusps, you have to use the Descendant. So, you place the Descendant degree so it would be five Scorpio in one of the hour lines that is four hours distance from the meridian and you get this. You’re measuring this distance between five Scorpio to the 23rd of Leo so that will be the cusp of the fifth and then of course two hours distance, you get the cusp of the sixth and then the remaining ones are just the opposite degrees. So you do this in minutes.

CB: Okay. And then you’ve got the intermediate house cusps using Alcabitius?

LR: Yeah. And that’s it as you can see very quickly to do.

CB: Yeah. This is important because there’s a bit of a historical thing here where we’re not entirely sure, historians are not entirely sure when the astrolabe was invented and when it became commonly used. Because we’re not sure if Ptolemy refers to it in the second century, some historians think he did and some historians think he didn’t, and there’s a little bit of ambiguity until you get to very late in the Hellenistic tradition. There’s eventually like one Greek text I think that gives you instructions on how to make an astrolabe in the fifth or sixth or seventh century CE, so like super late in terms of the Roman Empire or Byzantine Empire. And then it’s not until the eighth, the ninth and 10th centuries, during the early Medieval tradition, that all of a sudden, the astrolabe just explodes and is everywhere and astrologers are using them and there’s lots of manuals and there’s different workshops that are set up by different people that make astrolabes. And from that point forward from the eighth to ninth centuries forward, it just becomes a common piece of equipment that all astronomers and astrologers have and use on a regular basis. Just as much as like today, all astrologers have a smartphone that they can pull out and quickly calculate the chart of the moment, this is kind of the Medieval equivalent is an astrologer could plot an astrolabe and know instantly not just what the Ascendant and Midheaven is but also they could calculate the other intermediate house cusps really easily. And over the past few months, I’ve been thinking about this and researching astrolabes more because I wonder if this isn’t tied in with the shift that occurred in the Medieval tradition towards the quadrant systems of house division where they already existed and there was already a precedent for them, but I wonder if the growth and emergence of the astrolabe as a common tool that was more easily accessible by the eighth or ninth century and the ease with which you could use one to calculate the intermediate house cusps, I wonder if that didn’t help to ease the adoption of some of especially the more complex systems of quadrant house division because calculating them just became something that was just super easy, basically.

LR: Yes, it is. Technology appears because there’s a need, and then technology changes the practices because it exists, so there’s a connection there as we were talking about that early on. Certainly, there were needs for another type of calculation, the astrolabe appears and then suddenly the practices change because you have a way to calculate things that you didn’t have before, and you have more complex mathematical models to compute the houses because they’re possible to calculate with the astrolabe. Yes, certainly there is a connection there, even with directions appears to have been a connection with it. Yeah.

CB: Sure. It’s like there’s ambiguity just because we don’t know when exactly the astrolabe was introduced and at what point it truly became ubiquitous. We know that it was certainly by the eighth or ninth centuries, but we don’t know at what point that really came into vogue and prior to that, so there’s some ambiguity there. But it’s an interesting thing to think about just the extent to which that may have been tied into this question that we’ve had for a long time about that shift that occurred in the Medieval period with the different systems of house division.

LR: Yeah, could be. There’s a lot we don’t know. We have a blank in records unfortunately that doesn’t allow us to know with certainty the answers to these questions. But certainly, we have enough hints that the astrolabe or a proto-astrolabe existed in antiquity or at least late antiquity, something is there because you see similar instruments, similar mechanisms, the ability to project, to make this kind of projection, the astrolabes already exist. It’s one small technological step for the instrument to exist. And if it’s done on wood or paper, [Luis laughs] then it’s not going to survive until today.

CB: Right. Yeah, for sure. But it’s interesting how, and I know one of the things you had said was that there were some astrolabes where for calculating Alcabitius, that was a very simple step to calculate those cusps because it’s just based on something that’s already a default that’s built into most astrolabes. But there were also some later astrolabes where they had a separate plate that was specifically for calculating intermediate house cusps using different systems, right?

LR: Yeah, yeah, and I can show you that I have one of those ready as well. We saw Alcabitius. Let me show you Regiomontanus. Let me share it again. And here you are. With Regiomontanus method, the plate has to have the houses calculated within because you cannot do the calculation in a simple manner as you did with the hour lines. So, what happens is that they’re going to produce an astrolabe that has these lines that are here, dotted lines which represents already the divisions of the space into those slices that we see either in the Campanus or in the Regiomontanus system.

When an astrolabe has these house lines which is the name, we are either observing a Regiomontanus house system or a Campanus house system, more commonly, Regiomontanus. And for example, apparently there are examples of these plates with the Regiomontanus system much early than the writings of Regiomontanus himself which makes it that the system was around a little bit before he became the spokesperson about it. Here it’s even easier because if you have the houses, once you have established the angles by putting the degree of the Ascendant on the horizon, it’s just a case of seeing where each of the lines of the houses will intercept the zodiac and then you have the values for all the houses. So, it’s very, very straightforward.

CB: Brilliant, okay. Somebody like William Lily for example probably would have used an astrolabe like this with the Regiomontanus house cusps especially when he was seeing clients on a daily basis and a client would show up and he needed the chart for that moment, it would just be a matter of glancing at the astrolabe and then he would have not just the Ascendant or Midheaven, but also all the intermediate house cusps.

LR: Yeah, immediately. And you’ll see these on papers, you know? They sell them, paper astrolabes, that people can easily have. And for example, in my PhD, I was studying the teaching of astrology in the mathematical classes, so this is roughly the equivalent in terms of age to our high school at this point. It’s pre-university teaching. And they are teaching them not only to calculate these positions using the astrolabe, but also when they don’t have an astrolabe present to make one themselves. So, they simply draw the system directly on paper and do the computations on the scheme that they’re drawing, just transporting this idea onto paper very easily.

CB: Okay. Yeah, brings up one other thing mentioning of Lily and the ease of this is also, because the other thing that also shifts from the late Hellenistic tradition to the Medieval tradition is there’s some traces of horary astrology that go back to Dorotheus in the first century just like a couple references in an otherwise largely electional context, but then it starts picking up by the late Hellenistic tradition where by the fifth century, you start to see a few chart examples that survive that are clearly horary charts and then by the eighth or ninth centuries, we have the first full blown textbooks on horary that exist or that survive from authors like Masha’allah or Sahl ibn Bishr and I wonder if the rise of the astrolabe and it becoming a ubiquitous item that all astrologers had and the ability to calculate the chart of the moment instantaneously without much ease, if that also could have helped to ease the popularization of horary astrology that seems to have occurred by that time in the eighth and ninth centuries forward as well just in terms of the ability to very quickly and easily cast a chart for when somebody walks up to you and asks a question to the astrologer and then casting a chart for that moment and then attempting to predict the outcome.

LR: Yeah. Well, it certainly would in the same way that the computer today allow people without any knowledge of mathematics and astronomy to be able to compute with correction a natal chart or horary or whatever. So yes, it would facilitate. We have still a lot to learn exactly how popular astrology works or consultation astrology works at different levels because you always seem to have a popular side of astrology, very quick consultation in the market stuff, sort of things like that and then you have a more sophisticated mathematical astrology which has been practiced in the courts by physician so people who have a much higher level of mathematical knowledge. So, how are the more popular astrologers calculating charts? Do they have the mathematical knowledge? What level of mathematical knowledge do they have? Do they have these instruments and tables available or not? How does it work in different periods? This is a question because if you’re having someone that is constantly doing charts, it has to have a way to calculate them first.

CB: Right. Yeah. And that makes me think of well, a lot of things. I mean, one, at any moment in history, there’s always astrologers operating at all levels of society and you do have astrologers that are at the highest levels of society that are serving like kings or presidents or what have you, but then you also have mid-level astrologers and you also have street level astrologers and it makes me think of the difference between… We know that there’s some of those astrologers’ boards that survive and some of them are very elaborate and what would have been very expensive pieces that look like chess boards that are made out of like ivory and stone or wood and gold and that you put the pieces on the board in order to recreate the chart once you’ve calculated it to show the client. But then you also have stories of astrologers that would draw the chart in sand, which would be a much more like simple and basic method of displaying the chart visually that would not be terribly expensive.

LR: Yeah, yeah. And you have certain charts those of the Neugebauer collection which are just graffiti in walls. [laughs] So you’re calculating just there and Romans are experts on graffiti on walls, but sort of a lot of materials, some of them quite rude but you have charts, you know? That’s being done in the middle of the street in the wall. How is that thing calculated? It’s a good question.

CB: Yeah. I remember there’s text from Theon of Alexandria who was an astronomer who lived in the fifth century, he was the father of Hypatia, and there’s a statement that he makes at one point about people that he wrote a commentary on Ptolemy’s Handy Tables because he had astrologers coming up to him that wanted information about how to use the Handy Tables of Ptolemy to calculate charts. It sometimes makes me think also of a division sometimes where even though there were some times like high level astronomers who were also astrologers like Ptolemy or Kepler, there was also different gradations in between in terms of sometimes maybe astrologers that were good at interpreting charts or being diviners or what have you and making predictions, but maybe needed help or were not as strong sometimes on the mathematical side of things.

LR: Yeah. As you can see sometimes of certain books or manuscripts where you see a very simplified form of astrology being practiced there which is a very simple abbreviation of astrological practice. It’s more generally one more popular practice most likely. So yeah, we do have these discrepancies with different levels of knowledge which is quite interesting as we still see today as well, yeah.

CB: Exactly. And that’s one of the biggest reasons why I advocate for and I think it’s been a good thing that astrologers have made inroads into and have entered into academia over the past two or three decades and that there’s been that movement that you and your partner were a part of for people who are primarily astrologers to go back to school and get their PhD and get their degrees in order to bring some of that knowledge into an academic context because that’s really an area where practitioners can bring something that’s useful and valuable as historians because sometimes some of the dynamics that occur in the astrological community today are very familiar to things that would have occurred 1000 years ago or 2000 years ago or what have you and a practitioner can bring something that’s useful and interesting from that perspective.

LR: Yeah, yeah. And those were an empirical understanding of how things work and how things are done which can enlighten or sometimes questions that remain unanswered. And yeah, certainly, certainly. And then at the same time, the fact that you’re doing in an academic level also allows you to reach more precise conclusions because then you have peer review from people outside that are going to regulate and make you challenge your own work and your own explanations to see if they’re really accurate or not, you know? It’s a very good and interesting process when it works well and I think the history of astrology has developed a lot in the last decades. And partially, it has also to do with people with a greater knowledge of its practice coming into the field and producing significant amount of works. Yeah.

CB: Right. All right. Well, I want to talk about that more to transition to mentioning the Astro project and your other things. But before we do that, is there anything else we should mention to wrap up our long discussion on the astronomy underlying the different forms of house division?

LR: Well, I think we’ve covered a lot [laughs] a long time.

CB: Yeah. I mean, I think the only thing I wanted to mention just to wrap it up is just one of the issues that’s going to be a lingering issue is as we can tell each of these approaches and each of these systems is based on some independent astronomical reference point or phenomenon that is actually a legitimate astronomical concept or reference point and therefore may have different symbolic meanings when we’re talking about what is the relevance for astrology and talking about looking at different astronomical phenomenon from a symbolic standpoint. So that’s unfortunately one of the things that will continue to be frustrating in terms of trying to decide on one form of house division or another is each of them are based on different and independent and somewhat interesting astronomical reference points that could be useful in their own right in some way and so that kind of complicates whether there’s really truly like one singular system that should be used or whether there might be some validity or usefulness to different systems and different ways or from different vantage points.

LR: Yeah, certainly. Let me just also add something which is in the tradition, I think what they’re trying to do with validating these different references as you were talking is to better describe the universe, how things work, so the universal structure that they’re interpreting around them. Is it the prime vertical that’s going to be more accurate? Is it the equator? Is it the ecliptic? What is it? And that is a way of equating with reality, the universal. They are experimenting. And I think that is the main motivator for their choice or for their discussion in the debate. And I wanted to point out this because nowadays, currently in our own time, we see a different debate. It’s not just a debate of astronomy or of how reality is better explained through this reference, but also there is another type of symbolism that is trying to be imprinted into these referentials which makes the discussion even more complex and makes us for example, today existing arguments that a certain system would be more adequate to describe a psychological state while another an event or another a mundane structure, which not wanting to go into questioning the validity of those ideas, I wanted simply to point out that that’s not what’s in the mind of traditional authors when they’re trying to debate these different divisions.

CB: Yeah, I’ve heard some people sometimes propose that for example and try to reconcile some people wanting to use whole sign houses versus quadrant houses like Placidus and some people, I hear this commonly proposed by different people, they’ll say, well, whole sign is more about concrete prediction and Placidus is more psychological. But I sometimes wonder if that’s not just a side effect of the fact that the whole sign tradition that they’re learning tends to be more predictive because it’s drawing on ancient traditional astrology versus the Placidus tradition that they’re learning tends to be based on late 20th century modern psychological astrology. It may not be that that’s inherently the property of each of those systems but instead, it may just be a byproduct of the context in which they have been practiced historically or are practiced today. So that doesn’t mean that that solution is not true or maybe it does have some validity to it, but I think people have to be careful about making inferences like that that could be based on misassumptions.

LR: Yeah, exactly, exactly. We have to be careful. And I’ve seen things like, for example, attributing quality of the author to which the system is attributed like Porphyry or Regiomontanus to the system itself which is, in my opinion, farfetched. You can’t do that. That’s not the point at all of the system. And besides, as we saw for today that attribution of authorship, it’s very, very questionable so you can’t really make that connection.

CB: Or you mentioned earlier that some people argue that you should use Regiomontanus for horary but they’ll use something else for natal astrology and I’ve seen some people do that for example saying that you should use whole sign for natal astrology but you should definitely use Regiomontanus for horary because that’s what Lily used. But the problem with that as you pointed out is that different astrologers in different eras that practiced horary used different systems like Alcabitius or even Masha’allah and Sahl used whole sign houses for some of their horary charts. So there’s not really any historical precedent that’s going to like fully answer that question.

LR: No, there isn’t. I think that’s a 20th century problem and I think it is a problem derived from people having computers [laughs] which can calculate these 30 more house systems and not knowing what to do with them. Yeah. And it’s something that begins very early because I remember for example, that idea of being present in Rudhyar’s work. Rudhyar somehow revive the Campanus system and so people who follow Rudhyar school would use the Campanus system because I don’t recall his reasoning, but he had the reasoning relating to the position of the man in the universe, which can be questioned, you know? Okay, it’s an idea, but you can see it from so many perspectives that I don’t know if that’s the way to go. But you do have that and I think that is a 20th century phenomenon. And especially nowadays, I think it’s a 21st century phenomenon is this application of different house system for a different purpose. That is unprecedented, completely unprecedented.

CB: Yeah, I mean, there’s a part of that similar to some traditions of astrology where you have just different certain schools of astrology like let’s say a small school of astrology that endorses specific approach based on the approach that is taught by the teacher of that school and then those that follow in that lineage tend to follow that approach. You pointed out Rudhyar and so some people have followed Rudhyar in doing Campanus or I mentioned in the 1950s like Margaret Hone and the faculty of astrological studies endorsing equal houses And so you have people today like Carole Taylor who follow in that lineage or some of the evolutionary astrologers for some reason, Jeffrey Wolf Green in the 1980s decided that Porphyry houses was the system of house division to use. So, there’s a whole lineage of evolutionary astrologers that all use Porphyry houses today or nowadays in more recent times, you have some of the people involved in the revival of Hellenistic astrology that promote whole sign houses such as myself and I’m sure some people who emulate that.

LR: You have the Koch system for The Huber Method which is the central system for their calculations. Yeah. Now, so many examples of that kind of schools of views.

CB: What did Zoller use?

LR: Alcabitius.

CB: Okay. Zoller, who was one of the first practitioners who revived the use of Medieval astrology in the 1970s and ‘80s, he used Alcabitius as his main system probably because he could see that that was the main system used in the Medieval period.

LR: Yeah, although I believe that at some point he also used Placidus before that. I’m not sure. I don’t recall at this point, but I remember that he advocated Alcabitius when I was learning with him yeah, at least as the system that they would use at that period. This was something of a debate in tradition in the early 2000s, which system to use and there were three basically, which was Regiomontanus, Alcabitius or whole sign. That was the debate.

CB: Right, because all the Lily people would have been using Regiomontanus. That would be like Holden, John Frawley maybe and Lily, Seward, yeah. Okay.

LR: Yeah. I think everyone that’s using Renaissance certainly more than astrology would be using Regiomontanus because that’s where the source is.

CB: Right, because that’s what William Lily used in Christian astrology.

LR: Yeah. People who were more focused on Zoller’s line of work and similar would go for Alcabitius. And then at that period, the whole sign system debate started to pop in with Rob Hand’s papers and stuff like that.

CB: Right, because that was one of the funny things that happened about the revival of traditional astrology is it went backwards or it happened in reverse where the Lily material was revived first in the 1980s. So like 17th century astrology was the initial revival. But then the Medieval stuff started being revived next, especially with Zoller’s work which really gained steam starting in the late ‘80s and early ‘90s. And then all of a sudden from 1993 and 1994 onwards, you have the Project Hindsight stuff which was the revival of Hellenistic astrology. And then all of a sudden, Rob Hand and Robert Schmidt started being very loud about the existence of whole sign houses and promoting that even though it was something that James Holden had been talking about since like 1984, but it was in AFA journals and the AFA was not as active as an organization, so somewhat obscure back then. Yeah. It’s interesting all those things and how this stuff happens just sometimes as a matter of circumstance in the astrological community. Yeah. All right. Well, this was surprisingly comprehensive. I knew we’re going to pack a lot in, but I didn’t realize how much historical and other contexts we were going to infuse into this episode, but this was really amazing. Thank you for joining me for this today.

LR: Well, it was a pleasure. Yeah. It’s been a long, long planning in this one. [laughs]

CB: Right. We’ve been planning this for at least like two years almost now. I think it was worth the wait and yeah, I’m glad we did this. I want to talk about first recommending your book On the Heavenly Spheres, which is one of my top five astrology books that if you’ve seen my videos for new astrologers, it’s what I recommend. And you’re thinking about putting out a revised version of that at some point, right?

LR: Yes, yes. We have plans for that and I will continue with the idea to update, revise some of the other things and then add new material. Yeah, so I hope to do that sometime soon. No deadline on that yet.

CB: And then you also practice astrology and you teach through your website which is academyofastrology.eu, right? Okay. So, people can find out more information about your work there. You also have the Astra Project which is at theastraproject.org which is more of a collaboration with academics and an academic approach to astrology in the history of astrology and you have an amazing YouTube channel where you’ve actually interviewed many academics who work on the history of astrology at youtube.com/theastraproject, so I definitely recommend people check that out. And then, more recently, so we’re doing this episode first because we’ve been talking about it for a long time and it’s a good warm up, but we’re actually planning on doing another episode on the near future to talk about the work of your partner and her book which was recently published just the past few months, and she sadly unexpectedly passed away just a few months ago, right?

LR: Yeah, exactly, exactly. It unfortunately, very sadly became her posthumous work.

CB: I just got it in the mail the other day, but it’s titled An Astrologer at Work in Late Medieval France, and so your partner, Helena Avelar, and that you co-authored all your books about and so we wanted to do this episode to get the house division thing out of the way and do warm up collaborating together on something like this. But next month, we’ll come together again to talk about that book and talk about Helena’s life and celebrate that work and the work that she did and that the two of you did together as astrologers. So I’m really looking forward to that.

LR: Yeah, that will be great.

CB: Excellent. All right. Well, thanks a lot for doing this with me. Thanks everyone for watching or listening to this episode of The Astrology Podcast and I guess that’s it. We’ll see you again next time. Special thanks to all the patrons that supported the production of this episode of the podcast through our page on patreon.com. In particular, thanks to all the patrons on our producer’s tier, including Nate Craddock, Thomas Miller, Catherine Conroy, Kristi Moe, Ariana Amuor, Mandi Rae, Angelic Nambo, Sumo Coppock, Issa Sabah, Jake Otero, Morgan Mackenzie, Kristin Otero and Sanjay Sreehari. For more information about how to become a patron and get access to bonus content such as early access to new episodes or private subscriber only podcast episodes, go to patreon.com/astrologypodcast. Special thanks also to our sponsors, including The Mountain Astrologer Magazine available at mountainastrologer.com. The Honeycomb Collective Personal Astrological Almanacs available at honeycomb.co. Astro Gold astrology software for the Mac operating system which is available at astrogold.io. And you can use the promo code ASTROPODCAST15 for a 15% discount. The Portland School of Astrology available at portlandastrology.org. Astro Gold astrology app for iPhone and Android which is also available at astrogold.io. And finally the Solar Fire astrology software program for Windows which you can from alabe.com, and you can use the promo code AP15 for a 15% discount.