Re: Hellenistic deliniations
The ancient astrologers certainly did use signs, starting with the Babylonians!!!
There is a way that the past happened and that texts have come down to us.
It is correct to say that astrologers of antiquity used signs differently than modern astrologers use them today. In addition to the elements, they talked about whether signs were "crooked or straight" (Dorotheus V:2); "rough-skinned, leprous, mangy, or scurvy" or "licentious" (Rhetorius.)
Vettius Valens in book 1:2 has quite a list of these sign attributes. For example, Aries is: "the house of Mars, a masculine sign, tropic, terrestrial, governing, fiery, free, upward trending, semi-vocal, noble changeable, procuratorial, public, civic, with few offspring, servile, the Midheaven of the universe and the cause of rank, two-toned...unaspected and ecliptic."
What Valens means by being "born under" a particular sign is the rising sign, not the sun-sign. For more information about how this rising sign functions, we have to look at the "houseruler" (apparently Mars, as Aries is "the house of Mars") and how it is situated, notably with regard to Venus and Jupiter.
In Book 5 Firmicus Maternus has a whole "planets in signs" cookbook that, allowing for the differences in people's lives from the 4th century to today, has a surprisingly modern cookbook feel to it. For example, if your MC is in Cancer, lucky you. You will be noted for "famous deeds" and can look forward to wealth and prestige in your old age. If your MC is in Taurus, life will be mixed. Your marriage will be scandalous, but your career will be "in a public place or temple" and you will also receive riches and honours later in life.
Intriguingly, Schmidt's statement that "a zoidion is a section of the zodiac that provides the manner of emanation for a planets action" is precisely how most modern astrologers view signs' agency today.
It is also correct to say that ancient astrologers had different names for our word "sign", often calling a sign a "house", just to confuse matters.
JA wrote: The Greeks seem to have viewed the constellations of the zodiac as places in which the gods lived...."
Have you got a source for this? I've been studying mythology for a long time and have never come across it. There were 12 major gods on Mount Olympus, plus assorted minor gods up there. There was a celestial meaning to Olympus, but it wasn't in any particular contellations. Moreover, Pluto (Hades) lived in the underworld, together with his queen Persephone. Gods frequently traveled on the earth's surface, sometimes in disguise. Poseidon (Neptune) ruled the seas. Hermes (Mercury) was notable for being able to travel between the different realms.
The Greeks did put their folklore in the heavens, but these figures often related to Zeus memorializing an individual-- sometimes a mortal-- through the constellations. In this way we get a transmogrification of very ancient pre-Greek dieties for Aquarius to Gannymede, or of Virgo as Astraea. Yet the Greeks also believed in all sorts of minor deities who inhabited various parts of the landscape.
These can all be checked out on Wikipedia.