Vitruvius warned Roman architects that library windows facing south or west would let the wind conjure bookworms, and 17th-century physician Jan Baptist van Helmont published a recipe for making mice from a dirty shirt and wheat in 21 days. This deep dive chronicles spontaneous generation, the doctrine that living creatures routinely arise from nonliving matter, from Anaximander's sun-cooked slime and Empedocles' random body parts to Aristotle's hylomorphism and the vital heat he called pneuma that supposedly bubbled oysters out of mud and barnacles out of rock hollows.

We follow the theory into the Middle Ages, where Augustine reframed it as ongoing divine decree and Gerald of Wales reported barnacle geese growing from crustaceans, a belief used to defend the virgin birth and to classify the goose as fish during Lent until Pope Innocent II ...