Renaissance astrology, in other words, was a premodern form of scientism, if we take scientism in its broadest sense of unwarranted reliance on science, or a predisposition to believe opinions that present themselves illicitly as scientific facts. It differed from our contemporary forms of scientism largely relative to its intellectual prestige. In the modern world scientism is parasitic on an enormous body of valid scientific achievements as well as on the dominance of materialism and utilitarianism in public philosophy. In the Renaissance, by contrast, the scientistic practice of astrology had to share the intellectual ecosystem with powerful traditions of practical reasoning that challenged its premises in fundamental ways: the moral theology of the Catholic Church and the moral philosophy of the ancient Greeks and Romans, taught everywhere in schools and universities.