As we’ve covered earlier, Christianity often gets a bad rap for its supposed detrimental effects on scientific work, particularly during the medieval period. Many contemporary thinkers similarly dismiss astrology and alchemy as worthless nonsense despite the fact that historians of science, such as David Lindberg, have shown that modern astronomy and chemistry would likely not exist (or would be very different) without these medieval precursors.
Astrology throughout the Middle Ages was not simply the horoscope and zodiac obsessed practice that we know today. It was a branch of natural philosophy dealing with the physical influence of the cosmos on the earth. Casting horoscopes, etc., was a part of astrology, but a contentious one. Many medieval thinkers criticized this part of astrology while accepting the idea that celestial events have an influence on earthly ones. And they had good reasons for doing so. For example, it was clear that the sun had a profound influence on the earth, bringing heat and light and causing the seasons. The moon also had a clear influence by causing the tides. Several Greek intellectual traditions considered the investigation of the connections between the heavens and the earth as a legitimate and rational enterprise. Interest in astrology was also in many cases the primary motivation for the expansion of astronomical knowledge. Astrology played an important role in the development of modern astronomy and was not entirely wrong in its descriptions of the causal influence of the heavens on the earth.
Also, it turns out that long before modern secularists dismissed astrology as a pseudoscience, the Christian church was its major critic. Some of the common tenets of astrology included the idea that celestial bodies were divine and could influence or determine the fate of human beings on earth. The church objected to both of these doctrines, asserting that humans have free-will and that celestial bodies were not gods that could determine events on earth.
