We are after all studying Astrology - the word or message of the stars, not Astrophysics - the physical properties and dynamic processes of celestial objects. The latter might well be very helpful in establishing the context of the message but the message is more than the properties and processes.
Well-said. After doggedly chasing the fine details for years, I now believe in honing the precision only to the point that I consistently get results I can accept as reasonably accurate. (I guess you could say I've evolved into a pragmatist from my previous state of hyper-rationalism.) For example, in rectification I'm finding that the precessed angles and planets seem to "tighten up" the timing of past events. Granted, in the charts I'm working with they shift less than one degree from their tropical ephemeris positions, but in looking for partile aspects it has some relevance. I'm working with them now in prediction since I can see their subtle contribution to rectification. And as an hermetic qabalist of long standing I certainly consider even the vaguest glimpses of the "mind" of God largely inscrutable until VERY high levels of attainment (if then). All we have to go on is what we can see of the "works" of that mind on the planes we're able to reach. It's been said that tarot functions on the "astral" plane similar to activities like scrying, whereas astrology would seem to operate on the "mental" plane. Put another way, I believe it was Eliphas Levi (but don't quote me on that ) who called tarot the "silver key" and astrology the "gold key" to enlightenment.
Edit: I didn't find it here, but this is an interesting site:
http://www.golden-dawn-canada.com/pdf/the key of the mysteries.pdf