Larxene wrote:

I am still wondering why the MC and the nonagesimals do not coincide despite both being in the local meridian.

This makes me further wonder: why does the MC even stray as far as the 12th sign when in extreme latitudes? I will have to think about it.

In my naive and simplistic way of looking at things I had assumed the MC was derived from the highest culmination point of the planets in a particular location where they intersect with the ecliptic.

This is from Wikipedia:

The other very important angle of the chart is the Midheaven (also called the M.C. for the Latin Medium coeli, or "middle of the sky.") The Midheaven represents the highest point in the sky reached by the Sun, or its culmination, as it crosses from one horizon to the other?the noon point in a chart which is plotted for dawn. At the Earth's equator, it is the point on the ecliptic which is directly overhead from the observer; as the observer moves north or south from the Equator, the midheaven appears to withdraw, so that from points north of the equator, the noon point of the Sun appears lies in the southern sky, and south of the equator, it appears in the northern sky.

http://en.wikipedia.org/wiki/Angle_(astrology)

I suppose an obvious question here is why isn't the MC a fixed point calculated for local solar noon in a chart for a whole day? We all know the Sun at local solar noon directly coincides with the MC. In other words why does the MC position keep changing? My understanding is that the MC indicates the point where the planets reach their highest declination in their arc between the ascendant and descendant and since the ASC/DESC axis is constantly shifting so must the MC.

As you travel further north of the equator the MC occurs more frequently nearer the horizon. Hence more charts with an MC located in the 12th whole sign house in northern latitudes. We get quite a few of those here in Scotland. Eventually, when you get to polar regions you will have charts where the Sun is too low in declination to ever rise at all so the MC is below the ASC! You also have the problem of certain zodiacal degrees not rising at all.

Here is an interesting article on the practical astrology of polar astrology by Andrew Bevan:

http://www.astronor.com/polarcharts.htm

If your more mathematically inclined you will be enjoy Michael Wackford's series of articles on the mathematics and astronomy of house division and the challenge of polar astrology:

http://www.skyscript.co.uk/books.html#ah

Overall, Michael Wackford seems to be a strong supporter of the placidus house system above any other.

On the nonagesimal my understanding is that it is derived from the local zodiacal zenith. Hence the etymology of nonagesimal being derived from 90 degrees from the ASC.

To quote Michael Wackford on the nonagesimal:

This cusp, which is always the point of the ecliptic highest in the local sky, is the ecliptic point closest to the celestial position of the birthplace ( = the celestial zenith)

So in contrasting the MC/nonagesimal we have the difference between the highest culmination point of the planets in terms of declination and the highest point of the ecliptic in the local sky.

Mark

Larxene wrote: Apr 26, 2014 6:41 am

I am still wondering why the MC and the nonagesimals do not coincide despite both being in the local meridian.

Not sure if I follow you here, Larxene.

The nonagesimal coincides with the local meridian only twice a day (when the equinoctial degrees 0? Aries and 0? Libra are at the ASC). While the MC (by definition) is always at the meridian.

In my last post I wrote that the ASC-DSC and the MC-IC axes don't have any straightforward relation to each other. This is true by comparison with the simple constant 90? angle between the ASC-DSC and the 10th-4th equal house cusp axes.

However, thinking about the issue some more, actually the former pair does have a mathematically well-defined mutual relationship as well, albeit not of such a simple nature.

While the MC-IC axis (aka the meridian) stays in place, the zodiacal ASC-DSC axis is shuttling forth and back periodically over the fixed horizontal positions the equator is rising and setting at (east and west, in other words). This is rather interesting in the geometrician's eye.

But if we do base our wheel of houses on the unequal quadrants thus derived, we are next, of course, faced with the question how to calculate the cusps in-between the axes. Treating this theoretically, it would be logical to assume that the further cusps somehow need to follow the same rationale like the main axes. - Perhaps the Placidus system accomplishes this.

As I mentioned before, some time-honoured systems start out by dividing one of the great circles other than the zodiac, such as the prime vertical (Campanus), or the equator (Regiomontanus). We would need to ascertain what these circles represent metaphysically in order to get a better perspective on their appropriateness in this respect or, possibly, on what level of a native's experience a particular house system pertains to.

Maybe all the different house systems have meaning, but in (subtly) different respects. If we were able to discern this, we could conceivably always use the house system that best suits the case at hand.

Perhaps the equal system (the simple division of the zodiac) could then be seen as the most basic and generally valid approach while additional house systems would be brought into play for inquiries into more specialised areas?

Paul's use of Equal and Placidus in parallel points in this direction.

The Rubik's cube is difficult to solve without using any algorithms, so even for myself, I have to use algorithms for the last layer.

Riiiight, Larxene... Why for heaven's sake couldn't I think of such a perfectly simple solution myself back in my elementary school days?!

Martin Sternbach wrote:

Perhaps the equal system (the simple division of the zodiac) could then be seen as the most basic and generally valid approach while additional house systems would be brought into play for inquiries into more specialised areas?

Leaving aside the controversial topic of 'validity' by 'equal system' can we assume you also include the other systems that do not use the MC as the 10th house cusp. In particular Whole sign houses and the Vehlow-Raman system?

Mark

Mark wrote: Apr 26, 2014 10:01 am

I suppose an obvious question here is why isn't the MC a fixed point calculated for local solar noon in a chart for a whole day? We all know the Sun at local solar noon directly coincides with the MC. In other words why does the MC position keep changing? My understanding is that the MC indicates the point where the planets reach their highest declination in their arc between the ascendant and descendant and since the ASC/DESC axis is constantly shifting so must the MC.

Actually, the ASC-DSC axis is constantly shifting, but the MC-IC axis is not. The projection into the flatness of our charts makes it look like the MC and IC were shifting during the course of the day while in reality only the ASC and the DSC are.

As you travel further north of the equator the MC occurs more frequently nearer the horizon. Hence more charts with an MC located in the 12th whole sign house in northern latitudes. We get quite a few of those here in Scotland. Eventually, when you get to polar regions you will have charts where the Sun is too low in declination to ever rise at all so the MC is below the ASC! You also have the problem of certain zodiacal degrees not rising at all.

I was waiting for somebody to bring this one up!

The discussion about what happens to our different house systems in more extreme latitudes is quite a complex one. It is somehow reminiscent of the ?tropical zodiac and the southern hemisphere? thread over on the Philosophy & Science forum.

Surely our understanding of astrology's foundations can only gain by considering such topics, tricky as they may be.

Thanks Mark for the informative articles you have linked. I didn't read them all yet but I will do so as my time allows.

On the nonagesimal my understanding is that it is derived from the local zodiacal zenith. Hence the etymology of nonagesimal being derived from 90 degrees from the ASC.

This is why the Equal house system is sometimes also called the Zenith system. - As an aside, Arthur Schult calls it the Hermetic system in his ?Astrosophie?.

So in contrasting the MC/nonagesimal we have the difference between the highest culmination point of the planets in terms of declination and the highest point of the ecliptic in the local sky.

Right on the mark! The question now is what distinguishes the two in regard of their astrological meaning.

Mark wrote: Apr 26, 2014 10:11 pm

Leaving aside the controversial topic of 'validity' by 'equal system' can we assume you also include the other systems that do not use the MC as the 10th house cusp. In particular Whole sign houses and the Vehlow-Raman system?

The whole idea would be quite controversial. So far, I've only been thinking aloud, really.

And I wouldn't exclude any house system as insignificant a priori.

Let me take a brief look at the theoretical foundation of the Equal systems you mention here (from my current perspective):

Whole sign houses

Here, the first house cusp is at 0? of the ascending sign, not at the Ascendant per se. This could be based on an ancient view that regards signs as a whole rather than taking into account individual degrees. It would seem a little simplistic from a modern astrologer's perspective. Personally, I never worked with this system. But I find the concept interesting, nonetheless.

Vehlow-Raman

In regard to this system, let me quote what I wrote above in response to Paul (in my post of Apr 25, 2014 10:39 am):

A problem with seeing the equal house cusps primarily as aspects to (or from) the ascendant could be that their orbs extend on either side of the exact degree, so a house cusp should become the same house's centre, really. Also, a 15? orb is wider than any other factor has (except the Sun in classical astrology).

Possibly, though, this is the rationale for the version of the equal house system which is indeed positioning the ASC in the middle of the 1st house.

Michael

It's hard for me to explain verbally, so let me use pictures instead:

Both the nonagesimal and MC lie on the local meridian, so they should be both 90 degrees from the eastern horizon. In other words, the nonagesimal and MC should both coincide; they should both be 90 degrees clockwise from the Ascendant. And yet, in natal charts, they do not. Why?

Larxene,

If you let us know the date, time, and location of this skyview, I will see what I can do for you.

Michael Sternbach wrote:Maybe all the different house systems have meaning, but in (subtly) different respects. If we were able to discern this, we could conceivably always use the house system that best suits the case at hand.

Perhaps the equal system (the simple division of the zodiac) could then be seen as the most basic and generally valid approach while additional house systems would be brought into play for inquiries into more specialised areas?

Paul's use of Equal and Placidus in parallel points in this direction.

Actually this is exactly what I believe. I actually think all the house systems have validity and depending on what your focus is may mean you wish to use one house system over another - one filter on the information over another. In a similar way, an item under a microscope will remain the same, but depending on the lens you use to observe it through will depend on what level of detail or context you wish to examine.

Michael Sternbach wrote: It may interest you that traditional astrologer Rafael Gil Brand in fact gives exactly the same explanation for the dexter square in his ?Lehrbuch der klassischen Astrologie?, p. 240 f. ? He further remarks that a planet at the nonagesimal will be ?elevated? over a planet at the ASC.

Thanks for this reference, it's always good to know that other people who have thought about the issue have come to similar conclusions - it doesn't prove anything but it's a good sanity check.

A problem with seeing the equal house cusps primarily as aspects to (or from) the ascendant could be that their orbs extend on either side of the exact degree, so a house cusp should become the same house's centre, really. Also, a 15? orb is wider than any other factor has (except the Sun in classical astrology).

Right, but I should probably add that we can see it differently and see it that upon completing its aspect with the ascendant, and at which point it separates (by primary motion) from the house cusp, it rapidly loses its influence upon the house. This is not new thinking, we think the same thing with houses anyway even if we don't imply aspectual relationships to the ascendant. In other words as a planet moves through, say, the fifth house, by primary motion, and is brought closer to the fifth house cusp it is imbued with the symbolism of the fifth, reaches a pinnacle of signification of the symbolism of the fifth upon completion/perfection of its trine to the ascendant, and then as it separates from that perfection it then goes 'cadent' from that house and it stripped of its power/signification in that house and begins to 'absorb' the symbolism of the next house (the fourth in this example).

I'm not sure if you follow what I mean. In this instance then we can see the exact partile degree as the perfection of the aspect, and as we're not dealing with secondary motion here, but instead are dealing with primary motion to abstract 'points' we can be less concerned with the applying/separating of a planet and its orb, which, for me, has more to do with being in the light of another planet. These points are not philosophically, perhaps, related to this same concept of orbs.

This is how I see it, and how I tend to use it. It makes a lot of sense to me, though I would add that I would never expect it to make sense to anyone else or have any desire to 'convince' anyone of it. I say it only as another way of looking at the issue. In this sense then we can see the cusps as the pivotal/pinnacle of the expression of the symbolism of that house as the planet involved has traversed 30 degrees through this house and now reaches its moment of perfection and then 'falls' away into the previous house, is stripped of its symbolism in that house (being 'cadent' from it) and then starts to build up signification in that house before doing it all over again.

This made me wonder - if unequal houses have their rationale in the apparent daily revolution of the Sun (or, by analogy, another celestial body) ? like Placidus in particular implies ? shouldn't the signs have different sizes as well? After all, the Sun doesn't traverse the zodiac at a constant speed either.

Well the difference, really, is that the MC marks the point at which EVERY individual point of the ecliptic will culminate, yes, that includes the Sun, and is probably the most obvious and easily observed in the Sun (after all we tell the time because of this motion), it is true of the other planets.

However the same is not true of the zodiac, it is not that during certain parts of the zodiac, all the planets move at a quicker or slower time. Yes, we do have signs of long and short ascension, but then some astrologers have dealt with this by converting squares to trines etc. when they occur in signs of long ascension to account for this phenomenon (whether we agree with that or not).

Really the cardinal points are analogous to the axes of our charts, and just like with quadrant houses where we establish our pivots and then divide the space in between differently depending on house system, we can divide the space in between the cardinal points any way we wish as well. But as we're using the zodiac to measure more than just the sun's passage (even if it's the most obvious and dominant) there is an argument that we ought not to change the arc of the signs based just on the sun. Instead we can divide evenly between them, and as they're 90? apart, we'll have our 30? signs - a porphyry house system approach which works out the same as an equal house system approach.

Of course there's no reason that what is true for the rotation of earth, ought to be true for the orbit of the sun around the earth anyway.

Even though I find the idea that ancient astrologers created the unequal system by misinterpretation of even more ancient texts intriguing, it would take a careful study of the relevant source material to see if this theory holds true.

I think, for me, one of the major arguments against this thinking is that several astrologers cite Nechepso and Petosiris when dealing with, for example, the length of life treatment, in which these 'ancients' state that we ought to find, say, the ascendant and the midheaven, and then divide the ecliptic evenly into three sections and do the same for the other angles. As so many seem to be of the same mind, and as we can assume that the idea of houses is likely to have come from Egypt, and as Nechepso and Petosiris are the ancient Egyptians to which later Hellenistic astrologers all bow to it seems unlikely to me that actually everyone was meant to be using equal house cusps and got it wrong. In fact it's much more easy to mistake quadrant houses for equally divided houses. It takes a lot more nuance and work to describe the calculation of the Midheaven and then to divide evenly the arc between the ascendant and midheaven. If we wanted to describe equal houses we'd just say find the ascendant and add 30 degrees for each house. It's much simpler.
Quadrant houses on the other hand are more likely to be misunderstood, if anything.

This said, unbiased laypersons often note the awkwardness of unequal systems immediately. When showing them their ?unequal? charts, I have heard some of them exclaim: ?Why the [insert your preferred expletive] is my chart so distorted?!!?, and also: ?Are you sure your PC is o.k.??

Right, but this tells us absolutely nothing about astrologers, calculations for astrology, or whether or not astrologers made a mistake on equal houses and accidentally invented a more mathematically complicated way of dividing the ecliptic.

For me it's really irrelevant what the average layperson says when it comes to astrology or what they think when they look at the charts, as calculations are not based upon what the average layperson thinks. It is true that very disproportionate houses can inspire some explication for the average layperson but then so can having all the planets in one hemisphere or having a notable aspect patterns etc.

Mark wrote: I suppose an obvious question here is why isn't the MC a fixed point calculated for local solar noon in a chart for a whole day? We all know the Sun at local solar noon directly coincides with the MC. In other words why does the MC position keep changing? My understanding is that the MC indicates the point where the planets reach their highest declination in their arc between the ascendant and descendant and since the ASC/DESC axis is constantly shifting so must the MC.

I think Michael's explanation has already addressed this for you, but just to add to it, if we recognise that the MC is really just another word for saying "exactly south from where you are" and that the acendant isn't actually exactly east, but is often north or south of east, then really we might argue that we should fix the MC at the top of our charts, and let our ascendant float up or down on the chart, rather than fixing it to the exact left of our charts. This would more accurately reflect what we're observing. Instead we put our astrological focus on the ascendant and so fix it to the left of the chart, for simplicity. But really it's the MC which doesn't move, as it's just another word for "exactly due south wherever it hits the ecliptic".

So in contrasting the MC/nonagesimal we have the difference between the highest culmination point of the planets in terms of declination and the highest point of the ecliptic in the local sky.

This whole topic has made me wonder about whether or not we should treat the nonagesimal and MC differently and apply some subtle nuance to its interpretation.

Really any planet at the MC is the highest it can get to in a given day, and so maybe we should see it as more 'personal' or more relative to the rest of the chart, so a planet at the MC is one which is at the height of its own power. In contrast a planet at the nonagesimal is at the height of the entire chart, it may not be at its own personal highest yet, or may even be declining from its own "personal best" but it's still overcoming the ascendant and is rising above all the other planets. Just like a star athlete may still win the race against weaker competitors even if personal private victories are going on with the other players as they beat their own personal best times.

Larxene wrote:

Both the nonagesimal and MC lie on the local meridian, so they should be both 90 degrees from the eastern horizon. In other words, the nonagesimal and MC should both coincide; they should both be 90 degrees clockwise from the Ascendant. And yet, in natal charts, they do not. Why?

The only way that the nonagesimal can lie on the local meridian is if Aries or Libra rise. If we imagine 0 Aries to be the intersection of the ecliptic with the equator, then it means that when it's on the ascendant the point 90? from it, must, be extension, be exactly south from our vantage point, and therefore will be at the nonagesimal.

I hope I have that right, someone correct me if I'm misthinking this.

Having said that, Larxene I'm not completely sure what you're demonstrating here with the graph. Just make sure that you are not expecting the actual Zenith to be on the ecliptic as the MC, as the two are not the same. The Zenith is the point that if you looked up directly over your head you would find. I wonder if the graph is showing this point - which is therefore not the nonagesimal.

I don't know, cos I'm not sure what I'm looking at.

I found the following piece from Deborah Houlding's article: The Problems of House Division.

http://www.skyscript.co.uk/houprob_print.html

I feel it summarises some of the points that have been already raised on the thread in non-technical language:

The Difficulties of Ecliptic-Based Space Division

The relevant issue is that houses, as an astrological technique, most certainly evolved from a separate foundation to that of the zodiac and thus demonstrate a different perspective of the heavens. The purpose of the zodiac is to map the secondary motion of a planet as it revolves in its superior orbit around the Earth, but the houses map the primary motion of a planet's daily journey through our skies. Their relationship with the observer is altogether more personal and direct, and through them the affect of a planet in the zodiac is grounded to reveal its specific influence upon any locality.

The difficulties of finding a suitable house system that will work well in all locations are the legacy of our decision to make the zodiac - and hence the ecliptic - the central crux of the horoscopic scheme; an underpinning principle which was firmly established by the classical period and is now so deeply embedded into the core of our art that any perspective but this appears irreconcilable. To understand why the difficulties arise, it is necessary to visualize the variability between the true cardinal directions and those represented by the ascendant and descendant.

As the Earth rotates on its axis from west to east, it appears from our apparently stationary viewpoint that the stars rise in the east, culminate on the upper meridian and set in the west. For an observer in the northern hemisphere the easiest way to observe the planets in the zodiacal belt is to stand facing south - one would then see the stars rising in the east on the left, culminating in the south ahead and setting in the west on the right: this is the perspective that is represented on an astrological chart.

Since the Earth is a globe, an observer from any locality will always be at the center of their own bowl of heaven, but in astrology the midheaven does not represent the point immediately overhead (our local zenith), but the point at which that meridian intersects with the ecliptic (see diagram above). The more northerly the latitude, the further down on the horizon it is likely to be. It will, however, always culminate due south, where the planets reach their highest declination before retiring towards the descendant. With the MC and IC then, there is true alignment between the astrological angles and the cardinal directions south and north, which is not usually the case with the ascendant and the east, or the descendant and the west.

Because of the tilt between the Earth's equator and the ecliptic, the ascendant will only align with cardinal east at two moments during the day - namely when 0? Aries or 0? Libra, the points of intersection between the equator and ecliptic, are rising. At such times the midheaven will be close to a 90? angle to the ascendant for all locations, but when other parts of the ecliptic ascend there is a discrepancy from due east, the ascendant being most northerly when 0? Cancer rises and most southerly with 0? Capricorn. Thus, 90? as measured along the ecliptic does not necessarily reflect 90? in geometrical measurement and there is a distorted angle between the ascendant and midheaven which becomes increasingly difficult to resolve with latitude. In the district of Alexandria (31?N) the variation is small and causes no real problems, but in high latitudes it becomes impossible for certain parts of the zodiac to rise at all. Of the signs that do rise, some linger on the ascendant for many hours while others speed by in a matter of minutes.

In the Arctic and Antarctic regions, the inherent problems can be illustrated through the phenomenon of the midnight Sun, which prevents any division of the chart into diurnal and nocturnal hemispheres. And though it may be an extreme example, how does one reconcile the fact that at the north pole, 0? Aries can rise on the ascendant and be on the midheaven simultaneously? Obviously, at these localities, the theory of ecliptic-based methods of house division become impractical in working astrology.

Paul wrote:

But really it's the MC which doesn't move, as it's just another word for "exactly due south wherever it hits the ecliptic".

Unless you live in the southern hemisphere. In that case its always due north!

Paul wrote:

This whole topic has made me wonder about whether or not we should treat the nonagesimal and MC differently and apply some subtle nuance to its interpretation.

Yes. Michael also raised this point earlier in the thread in his reply to me. I agree from a practical astrological point of view it seems the key issue. I have been pondering this issue for a while myself as I use whole sign houses but take equal cusps as the sensitive points within the houses. Along with the MC/IC which I also examine. Perhaps we should consider opening a new thread entitled MC vs Nonagesimal?

Mark

great conversation folks! i feel like i have little to add or more specifically don't have the patience paul and others have to go into the many details here on the thread, and i can't say that i understand them fully, but in my own way which of course has holes in it. i really enjoyed what paul had to say in the 12:56pm post from today. thanks for that paul. i just want to pick up one comment from paul in his 1:06pm post that i've quoted below.

Paul wrote: This whole topic has made me wonder about whether or not we should treat the nonagesimal and MC differently and apply some subtle nuance to its interpretation.

i think this makes a lot of sense and i think you've done this by highlighting the concept of 'overcoming'. that isn't enough, and other ideas have been articulated, but i think you're doing this. i wonder if anyone wants to do the same with the east point, vertex/anti vertex and other important astronomical considerations that generally get overlooked by a large number of astrologers? part of the reason i think they get overlooked is because we don't fully understand the mechanics of them. i could be wrong, but really that is what this thread is trying to do in distinguishing the nonagesimal with the mc. we could be doing it with a few other relevant points in the chart too - perhaps on a different thread.