Who invented whole houses? My Hellenistic astrologer friends would say, “Easy, Hellenistic astrologers.” And if I want to pull their legs I ask, “The modern ones or the ancient?”
I don’t think that anyone would argue that the oldest astrology known is that of ancient Mesopotamia. Nor that the 12 sign zodiac, divided into a circle of 360 degrees, the sexagismal number system to measure both arc and time and the use of ephemerides for finding planetary positions were some of the Mesopotamian contributions to astronomy/astrology. The few Babylonian ‘horoscopes’ available to us all have the character of recording the celestial omens for the birth. The position of Sun and Moon and planets are given and any notable celestial phenomena such as eclipses might also have been recorded. There is no Ascendant. Charts were not used, but then even in the Hellenistic period charts were not the usual form in presenting a horoscope. A horoscope was recorded in simple list form. This means that only an equal, whole sign visualisation was possible.
What was the Hellenistic contribution? First the concept of the rising degree, the horoscopos, from which we derive our term of horoscope and as a consequence the concept of mundane houses. So we can say that the Babylonian used whole signs and early Hellenistic astrology did indeed use whole sign houses. A later refinement was equal sign houses in which the Ascendant degree determined the cusp of each house. There seems also to have been some experimentation with using the Part of Fortune rather than the Ascendant as house determinant. But this wasn’t the end of the line, there was more to come. In a certain sense, at the beginning of the Christian era in 333 AD, Hellenistic astrology hadn’t reached its full potential. It’s fullest flower was when it no longer was ‘Hellenistic’ but Islamic.
One notable difference between Babylonian and Greek astroscience is that the Babylonians used arithmetic to solve their astronomical problems. Arithmetical progressions where useful in describing planetary cycles. I suspect that such divisions as the terms have a Babylonian arithmetic progression concealed in them. Just which has yet to be discovered. The Hellene prefered geometry and invented trigonometry to solve astronomical problems. Ptolemy’s Almagest is the classical example. (by the way, Almagest is from the Arabic and means ‘the greatest’. The English word ‘majestic’ could also be used). All systems of house division used today are in fact based on geometric division of the celestial sphere. (See Rüdiger Pantiko’s essay, ‘On Dividing the Sky’) This is Hellenistic. In fact any form of geometrization can be considered such! So whichever house system you use, it is Hellenistic. 🙂 But Hellenistic only means one stream of inheritance. In fact the astrology practiced today is a blend of many different historical periods. Some no longer recognizable because thoroughly integrated into the substance of astrology (360 degrees for example). What it boils down to is that many discussions as to which was first and which is best and which works best because more ancient are superfluous. Astrologer, if you are wise, explore all roots of astrology. And while you are at it ask yourself what the modern contribution is?