A study of thirteenth-century philosopher Roger Bacon that reveals the medieval thinking that erased non-Christian texts, actors, and cultures from the history of science

In his works, thirteenth-century English scholastic philosopher and Franciscan Roger Bacon depicted an enticing future that included, among other technological marvels, vehicles of unimaginable speed without animal power, diving bells for exploring the ocean floor, and mirrors and lenses that could incinerate whole armies. These speculative technologies exemplify the promise of scientia experimentalis, Bacon's term for his theory of scientific knowledge production, and which relied on both theory and experiential knowledge to get accurate knowledge of the natural world. In the centuries after his death, others constructed Bacon's inventiveness and anticipation through partial readings, creative mistranslations, and purposeful distortions of his work, especially relating to scientia experimentalis.

In Necessary Inventions, E. R. Truitt uses Roger Bacon and his afterlives to establish and critique the role of periodization in the historiography of science, specifically the divide between "medieval" and "modern." Truitt shows how, in his lifetime, Bacon was part of an intellectual current of men at Oxford and in Paris, and he consulted texts written in Arabic, newly available in Latin, from which he borrowed, synthesized, and Christianized knowledge about optics, experimentation, and other topics. By the nineteenth century, however, Bacon was understood within the history of scientific development as a brilliant visionary who foretold (or, according to some, invented) later technologies and whose theory of scientia experimentalis anticipated the scientific method by five hundred years. This framing implies that Bacon's own time--the Middle Ages-- was one of intellectual immaturity, and that Bacon's ideas were precocious because the period in which he lived was an era of intellectual stagnation, hostile to rational thought. Truitt exposes the history of this characterization of the medieval period, showing how it organizes both the historiography of science and the narrative of scientific progress.

Uncovering the logic of replacement theology that undergirds the characterization of Bacon as a prophetic figure of scientific modernity, Necessary Inventions reveals the medieval thinking that enabled modern science to tell a story of scientific development that erased non-Christian texts, actors, and cultures from the history of science.