Taken from an earlier posting.
I've copied portions of a previous thread entitled "Different House Systems" initiated some time ago by M-Press. This is take from my comments in that thread.
Consider first the zodiac and the equal house system. Both are defined as having 12 equal segments measured as 30 degrees. Now consider the standard aspects -- most are based on one or more 30 degree increments. There are, of course, the semi-square (45 degrees) and the 135 degree aspects that are also quite common, but the most common aspects used are multiple increments of 30 degrees. One could look at these characteristics and decide that the equal house system is the most natural.
So, what is the rational of all the other house systems? We know that they are more or less distorted in terms of house size/coverage relative to locational latitude. What does this mean to us? We experience seasonal changes wherein the Sun is above the horizon longer than below it, and then it all flip flops. We have to ask, "Is change and distortion more natural than evenness and regularity?
Now that we have two right answers (or two wrong answers), do we have other choices? Yes! Don't use any house system. How could you not use any house system? You could just use the angles (they are the same in almost every house system). Now, we have three choices -- Equal segments, Unequal segments, or just the chart Angles which are often bigger unequal segments unless the ASC to MC arc happens to be 90 degrees.
If, at this point, one is confused about house systems (even before we get deeper into them) we could choose to abandon conventional charts and use the awesome mid-point system wherein signs and houses are not primary factors. And then there are other choices, for instance you could go vedic. Or just rely on Tarot.
If we wish to get back to actual house systems, then we should look at several of them, understand in broad terms how they are different, and then consider what their strengths are and where we should or might apply them.
*** The Porphory House system divides the ASC-MC arc and the MC-DSC arc equally. This leads to narrow houses on one side of the MC and wide houses on the other side -- all the narrow houses being equal in size and all of the wide housed being equal in size. This doesn't fit with equal house, zodiac or aspect relationships AND it doesn't make for a smooth distortion of the houses. Perhaps we should throw the Porphory system out or at least hold judgement on it.
*** Regiomontanus and Campanus House Systems. The Regiomontanus House system divides the equator equally and projects the house cusps onto the ecliptic -- a blend of equal and distortion systems. This may not be bad. The Campanus does the same thing except that it projects from 30 degree segments from the Prime Vertical. Perhaps we can say that if you want to do an experience or sensation oriented chart you should use Regiomontanus (based on the ASC & equator) and if you want a consciousness based chart you could use the Campanus (based on houses projected from the prime vertical and MC/IC axis.
*** The Morinus House system uses a different method of equal-equator divisions and projections wherein the ASC is defined as being 90 degrees from the MC's longitude -- perhaps this is a balanced Self and Experience system, perhaps useful for a spiritaul chart reading.
If there is a valid basis for any house system then there has to be a reason for using it and not another -- hence astrologers use that which "feels" good. In fact, they ought to know why they choose and use a house system and how to interpret the chart based on that house system. As far as I can see almost every astrologer makes no difference in interpretation based on the house system they use. This should give you something to think about. Dave.
