Lillygjc, regarding correspondences between planets, signs, and houses:
I do modern astrology, and I don't find a link to the 11th (or any) house relevant to the astrology rulership question. One of my pet peeves with **some** modern astrologers is that they conflate signs and houses, as if it made no difference whether somebody had Venus in the 4th house or Venus in Cancer. So I would not associate astrology with the 11th house at all, even though I am OK with Uranus (the sky god) as astrology's ruler. [Or Mercury.]
One handy desk reference that I use a lot is an AFA publication, Rex E. Bills, The Rulership Book, which is based on a decent bibliography. Some entries in this compendium have house rulers, some don't. Interestingly, he gives astrology to Uranus and Aquarius, never mentions either Mercury or the 11th house, but then lists as secondary rulers Neptune, Pisces, and the 7th house! Well, Neptune and Pisces I get if one thinks of astrology as metaphysical rather than empirical and mathematical; but the 7th? Maybe this refers to one-on-one counselling, I don't know. But the point being that rulerships can have a sign and/or planetary ruler that have no accompanying house, or else that don't have the "natural" house relationship. Some do in his book, and some don't.
Lilly, I wouldn't recommend "playing around with rulerships" so much as someone (with more time and expertise than I have) doing some research. I don't do horary astrology (where I think the majority of astrologers wouldn't use modern planets anyway.) Other than that, we might consider where else the rulership problem actually matters. One area would be the use of so-called "accidental house cusp rulers" or "lords" of the signs on house cusps. This practice generally leaves out the problem of "natural house cusp rulers" where the affinity between Uranus and the 11th would lie. (Some modern astrologers would look at a house's "natural ruler.") Possibly the situation of Uranus vs. Mercury in a chart could suggest who's likely to be a good astrologer and who isn't.
Consequently, in terms of Mercury as the ruler of astrology, I also wouldn't see a necessary affilitation between the 3rd or the 6th house for astrological matters.
Olivia, it is interesting that the Catholic church had such a complex relationship with astrology. On the one hand they condemned it, but then clerics were responsible for translating many of the great classical astrology works into Greek and Latin from the Arabic, when the original versions were lost. The Church fostered astrology in medieval universities for some centuries, then came down very hard on it during the late Renaissance, when it was seen as a challenge to papal authority.
The fundamental problem with astrology to the Christian mind, I think, based upon biblical antecedants, is predictive astrology's danger of turning people away from faith in God. [Or one might argue, from faith in church leaders.]
From a secular perspective I think the more fundamental problem with traditional astrology and why it got dropped from university curricula, is that its determinism just didn't seem to fit new paradigms of thinking, criteria for evidence, and revolutionary discoveries in astronomy.
Intriguingly, "traditional astrology" was the only kind that was practiced, even in the US, through the early 20th century. When popular astrology makes a comeback, it is not through a scientific, academic approach, but through occult metaphysical circles like the Golden Dawn and the theosophists. They get picked up by people like Dane Rudhyar and "modern astrology" sort of takes off from there.
Andrew, you look like a natural! How does one calculate the Part of Astrology, and what does it mean?
Anyone here heard of the "astrologer's degree" at 11 degrees Virgo, or use the asteroid Urania (muse of astronomy/astrology)?