When the Bubonic Plague hit Western Europe in 1347, it began a pandemic that killed between a third and a half of the population in only three years. The fear and horror of the sickness was exacerbated because no one knew why it was happening. Without the scientific method, germ theory, or knowledge of the immune system, explanations were driven by conformation bias aimed through the lens of Ancient Mediterranean medical theory, Christian theology, and primal fears of “other/outsider” groups that could include poor people, lepers, and particularly Jewish people. The Vicomte of Narbonne wrote “we believe that it is certainly the combined effects of the planets and the potions [in this case, poisons he thought beggars were deliberately using to pollute the water systems] which are causing the mortality.”
Source(s): “The Black Death and the Burning of Jews,” by Samuel K. Cohn, Jr. In _Art and Present_, no. 196 (Aug 2007), pp 3-36 at p 9. Image from Toggenburg Bible, 1411.
