House systems are a thing that I have always wondered about ...
It is really cool, actually to see a summary of where all the different systems originate ...


Zane probably knows more about it but the kind of house system I would think would make the most sense would be the one that most closely resembles the patterns between the cycles of the moon and the sun.

I think all the different systems are approximating or modeling the same thing. If I compare the division into 12 houses to the division of a year into 12 months equal house would be like saying all the months have roughly 30 days.
In reality each lunar cycle varies slightly. I'm no expert but I checked it out once on a calendar (from one full moon to the next). It is amazing to think that the complexity of varying cycles of the moon (as viewed from earth) could be captured by a single house system but given the fact that the moon is in roughly geosynchronous orbit it doesn't seem like that big of a stretch - although it would still only be a model. Similar comparisons make sense to me if one were to divide the day into 12 - 2 hour periods. I could see how each of those 2 hour periods might span a different angle of the sky - although this is starting to get a bit past my own depth of study into things ...

I guess I would expect none of the house systems to be perfect. It seems like they are each just trying to capture this pattern of the dance between the sun and moon which is kind of amazing if you think about it.

Although I do hear that the moon's orbit is slowly changing (getting closer or further away from the earth -not sure I remember which) ... something interesting to think about. I guess it is all just a model of the amazing pattern that lights our skies :)

Does anyone else use Campanus? Research on record rainfalls done by Donald Bradley in the '50s suggested it was the way to go.

I think I finally have it now. Mercury is my chart ruler because I have a Virgo Ascendent. In Sidereal Astrology, my Ascendent is Leo, so the Sun would be my chart ruler in that system. In Vedic Astrology ~ who knows? I might be a cashew with peanuts rising. It gets so confusing and weird. It also starts to look highly arbitrary after a while.

My inclination is really to stick to Tropical Astrology and deal with Placidus and Koch systems. It may be that I have a hard time wrapping my head around looking at my chart from the perspectives of these other forms of Astrology, or maybe I am so used to Tropical that it makes the most sense to me. But it really also seems like the best reflection that I have seen so far of how I see myself. While there may be some few people who could view me as a Leo with Leo rising, I think that most people who know me see Virgo rising, as I do. There are any number of criticisms about how Tropical Astrology is totally inaccurate due to not considering the precession of the equinoxes, etc., but somehow it just seems more apt for me. Maybe I am stuck in some Medieval past life where it was less of a problem. LOL!

Great thread.
I think part of the problem is that different house systems appear to work on different levels, as strange as that may seem.
I started off using Placidus, years ago, and still do for event charts and horary charts.
But for charts for people, I use Koch for adults, and Equal House for children, and look at both when I want to see how a child's perceptions and attitudes changed when they left the home and began dealing with the world on their own.

Ed Falis had a great article on this idea years ago, although of late I think he uses just the whole sign house system:

HOUSE SYSTEMS - BY ED FALIS

You'll find advocates of many, many house systems, each swearing that the one s/he uses works most effectively.

I use a "3D" version of Campanus for most of my natal work. I don't do much in the way of event-oriented work, which may explain my preference somewhat after the explanations below.

My fundamental assumption is that the different frames of reference used to derive the house systems each has a validity - each offers a perspective or point of view on the chart. The trick is in using analogical thinking about how the system is derived mathematically to define the perspective you’re viewing from. This assumption is based on my experience and thinking about the issue. Your mileage may, of course, vary.

Based on this assumption, there are two kinds of house systems: geometric and proportional time.


STARTING POINT

For both geometric and proportional time systems, we start with the space around the earth. The center of this space for most systems is the location of the "event", though for some systems the center of the earth is used.

We imagine this space as a sphere with infinite bounds around the center point. The space could also be viewed as a cubic space with x, y and z coordinates, but since astrological work is intimately interwoven with the idea of cycles, it tends to be done only in a spherical conceptual space.

Now we'll talk about geometrically derived systems, but note that all systems embody the complementary derivation as a background. "Space-based" systems are implicitly driven by time; "time-based” systems implicitly work against a geometrical/spatial background. Each heightens the perception of one element and puts the other into the background. This is why treating the systems as points of view has power - any point of view reveals some aspects of a whole while
hiding others: it's in the nature of our attention.


GEOMETRICALLY- DERIVED HOUSE SYSTEMS

Derivation of a geometric system starts with determining a plane through the sphere to be used to make the equal divisions corresponding to the houses. The plane is viewed as a "great circle"
on the surface of our imaginary sphere, and the houses are defined by dividing the circumference into 12 30-degree sections. Some of the planes used in various house systems are the celestial equator (regiomontanus), the prime vertical (campanus), the horizon (Zenithscope / "local space"), and the ecliptic ("equal house").

Next a plane or space within which to determine a house position for a body or point is selected. In most systems, this is the ecliptic, or standard zodiac. Note that unless the measurement plane is the same as the house derivation plane, the houses will have unequal sizes in the measurement plane. By analogical reasoning, the unequal house systems are a bridging or synthesis of two distinct perspectives (more on this later).

Finally, a zero-point and direction of measurement is selected. With typical house systems the zero-point is the intersection of the horizon with the ecliptic (the ascendant) and the direction is
counter-clockwise - the order of numbering the traditional/modern houses. Sound arguments can be made for a clockwise measurement as well - see Joseph Crane's reconsideration of the lunation cycle in the Feb/Mar issue of The Mountain Astrologer, that gives some idea as to how one might apply the same approach to diurnal motion.

Many natally-oriented astrologers seem to prefer geometrically-derived systems, though there is definitely an effect of preference based on whichever table of houses happened to be widespread in a given locale before the widespread availability of astrological software (e.g. the Placidus preference in the US). Michael Myer and Gordon Brown have recently written about this
preference for Humanistic Astrology as one that provides an undistorted representation of personal psychological ("local") space.


PROPORTIONAL-TIME SYSTEMS

Proportional-time systems are derived by equal division of the time for a point in space to move from one geometrical divider to another. The common systems (Placidus, Koch, and more obscurely, but worth mentioning, the Topocentric) divide movement from the ascendant to
the MC, MC to descendant, descendant to IC and IC to ascendant in various ways. As commonly derived, the points are points on the ecliptic, derived mathematically. I believe placidus divides each of the quadrants defined above into equal periods of time, and looks at
where the ascendant would be at each elapse. I believe Koch looks at 30-degree divisions of right ascension/sidereal time, measured from the RAMC and calculates ascendants for each of these to
locate the intermediate house cusps. The topocentric system uses a model based on equally dividing an "apparent cone of rotation" of the sky from the position of the observer. So, each of these has an implicit geometric component.

Some of the systems, when used for progressions and transits, take into account a body's deviation from the ecliptic (celestial latitude) when timing events, as seems logical; others don't.

I've found that astrologers working with events tend to prefer a proportional-time system, as these systems are according to these practitioners more effective/precise for timing events.

The topocentric system is interesting in that its originators based its theoretical explanation on empirical timing. The value of its inductive derivation was questioned by Geoffrey Dean in Recent Advances in Natal Astrology, where he pointed out that there were so many potential contacts that the findings used in the derivation were statistically insignificant. I found the system reasonably effective when I studied it.


PROBLEMS WITH APPLICABILITY OF SYSTEMS

Many house systems (in particular those that project or measure in the ecliptic) run into problems at extreme geographic latitudes. This is because there are times when the mathematical foundations of their derivation fail. For instance, the horizon can coincide with the ecliptic at the arctic and antarctic circles, making it impossible to define an ascendant (the point of intersection of the horizon and ecliptic). Or, for systems based on proportional division of a quadrant of movement in time, a point on the ecliptic may never appear above or below the horizon at certain latitudes and times of year, so no basis for division of time occurs. The topocentric system has a somewhat odd alternative formula for dealing with this.

Another problem with most systems is the insistence of working on the ecliptic. All the systems mentioned so far that measure position in the ecliptic place bodies depending on their zodiacal position relative to the zodiacal positions of the house cusps. This can easily lead to placement of a planet with a large latitude above or below the ascendant/descendent axis, when the body is actually on the other side of the horizon (eg. pluto placed in the first house after it's risen). A solution to this is center house-oriented analysis on the basis of position in the plane of division for geometric systems, and to refer to the ecliptic for synthetic information, such as sign
relationships to the house cusps.


PHILOSOPHICAL MEANINGS - WHICH HOUSE SYSTEM FOR WHAT?

Ok, these are my current set of opinions, based on thinking about this for some time.

The starting point is that we exist in multidimensional space-time. Choice of emphasis on time or space is nothing other than that - choice. We make distinctions to help ourselves understand and act effectively. We then elaborate these distinctions as logical systems used to discover order when we apply them, or to filter what we experience so we can deal with it from a given perspective. If this is the nature of cognition, then different systems will work in different contexts, for different intents.

Where I find a problem is with the "one, true perspective" approach - a single effective system in a context is generalized as the only way to do things. The distinction and elaboration at its foundation is forgotten in its application - its context and intent are lost. I think that this effect is very prominent in the use of houses. And this is why there are so many arguments over it - as we blind people touch the elephant, we have valid perceptions and reasoning, but we forget that we're blind, and are experiencing a partial perception intimately tied to our perspective.

In software development, a lot of effort has gone into modeling the systems we build. Some of the more sophisticated practitioners have come to the conclusion that our models (views on the system) can only be partial - that a given system can only be well understood by cycling through multiple models using different perspectives. A view oriented towards events or behavior of a system brings some aspects to attention and hides others; similarly for data (space), functionality and agency (who does what) views. The whole system eludes a given view because it exists at a level beyond these conceptualizations.


IS IT ANY DIFFERENT WITH ASTROLOGY ?

House systems fundamentally are trying to describe the interaction of local space with more generic orbital relationships (described by zodiacal positions) as mediated by the daily axial rotation of the earth. They do this through what are essentially mathematical abstractions: arbitrary distinctions (with some physical correlations) such as horizon, prime vertical, prime meridian, zenith/nadir and paths or trails of either the physical bodies or abstract mathematical points.

Is this anything other than a modeling system to help us understand and order our experience?

If it is a modeling system, then the characteristics of models used in software, mathematics and systems theory are likely to apply: that the reality can be captured only partially in any given model, and that the meaning of phenomena in that model are driven by the intent and derivation of the modeling tool. Not to mention the experience of the practitioner in correlating the abstraction with phenomena.

In local space relative to the observer, two common measurements are available: measurement by prime vertical (the foundation of Campanus) and measurement along the horizon (local space directional). One is a vertical measure; the other horizontal. These are perhaps the closest frames of reference to the individual, and should measure the most personal experience in these two dimensions. Thus, Rudhyar and the Humanists preference for the Campanus house system for psycho-spiritual work (the vertical dimension), and the use of the horizontal system for physical and geographical work.

A system like Regiomontanus, which divides the equator moves more to the implicit diurnal motion perspective that is attacked more explicitly by Placidus, Koch and the Topocentric approaches. Now event is the perspective we look, with varying degrees of remove from the spatial abstractions of the geometric systems.

The equal house systems, based on MC, ASC or Sun (or other body for that matter) are basically casting the physical relationships of the planets within the distribution of the meaning of the primary point used. A cycle is a cycle, complete with phases that cut across the particular cycle being studied. These systems measure the cycles of the points or bodies mentioned in the frame of the earth's orbital relationship to the sun - somewhat more remote than the first two sets of perspectives.

And so on. The orbital cycle of the earth can be viewed in the plane of the ecliptic, geocentrically or heliocentrically. Aspect relationships can be viewed in the ecliptic or along great circles as geometry, or as a phase cycle in the orbital plane of the slower planet. To treat time or space in the foreground, its complement recedes.

And to further open up the wonderment, we can relate two perspectives, as most house systems do, by projecting measurement in one plane into another, typically the ecliptic. The problem with this is that it corresponds to our modern tradition, where we've forgotten that we're projecting local space or time into orbital space/time and often confuse the two. So we treat a planet above the horizon as in the first house - we abstract a bit too far from what's in our faces when we go outside and look at the sky. And we engage in endless debates about the relative merits of our abstractions and points of view, instead of communicating the true sophistication of
this reality-modeling discipline in which we engage to the rest of the world.

Oh, it is you.

I am still studying. BTW, did I inspire you for this topic?
the way the ppl explain the houses is very interesting. Very basic, very deep.

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Before moving off the topic of Houses it is worth noting the concept of the House Ruler. The House ruler is quite simply the planet that rules the sign on the cusp of that house. If your 5H cusp is in Aries, then Mars will be the 5H ruler or delegate. The position and house of Mars will shed more light on how you interact with 5H issues, and any aspects that Mars makes will also be affected. So houses can be linked up in very interesting ways which really go toward making us even more complex characters!
Because of this you can have an empty House but that does not mean you do not 'do' that House. After all, there are 10 planets and 12 houses so it's likely we will have some empty houses!
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I think I know the answer to this ... but I'm not totally sure.
I have heard that planets and angles within a house are modified by the house ruler.
But in my case I have a majority of houses starting at the end of a sign.
So for example, mars is in pisces H10 - but the H10 cusp is in aquarius - so would mars be modified by neptune (pisces), uranus/saturn (aquarius), neither or both?