Something our esteemed Bad Astronomer seems to have overlooked in his debunk of Astrology is that there is an extremely powerful force, or set of forces, operating right here on earth that could explain most of Astrology's claims. When you consider the effects of group psychology and the fact that humans seem to have an instinct to believe in a higher power guiding our destinies as well as our "ability" to perceive even one result in line with our preconceptions as "confirmation" while dismissing all anomolous results as unworthy of attention... It's not difficult to envision how those early scholar priests were able to build up such a body of psychological "knowledge" based on seasonal movements of the sun, moon and visible planets. Perhaps some of their observations were even valid and based on seasonal differences in child-rearing at times when resources were relatively scarce or plentiful. We may never know for certain whether that is the case, but it seems clear to me that Astrology became its own self-fulfilling prophecy due to cultural expectations that children would exhibit the qualities of character related to their "birth sign".