"Brick by brick, century by century, with occasional burps and hiccups, the wall of superstition has been coming down. Science and medicine and political philosophy have been on a relentless march in one direction only -- sometimes slow, sometimes at a gallop, but never reversing course. Never has an empirical scientific discovery been deemed wrong and replaced by a more convincing mystical explanation. ("Holy cow, Dr. Pasteur! I've examined the pancreas of a diabetic dog, and darned if it's NOT an insulin deficiency, but a little evil goblin dwelling inside. And he seems really pissed!") Some magical presumptions have stubbornly persisted way longer than others, but have eventually, inexorably fallen to logic, reason and enlightenment, such as the assumption of the divine right of kings and the entitlement of aristocracy. That one took five millennia, but fall it did."
~W Gene Weingarten