Medieval thinkers argued rational persuasion, not crusade war, would convert infidels

Evidence

Roger Bacon was one of the most avid readers of the Itinerary of his fellow Franciscan William of Rubruck. Bacon attempts to turn William’s debating strategy into a veritable science of religion, bent on converting the infidel through rational argumentation. … For Bacon, the fruits of centuries of crusade and mission were scant: “there are few Christians; the whole breadth of the world is occupied by unbelievers, and there is no one to show them the truth.” No one, that is, until Roger Bacon came along. War does not win converts; it kills infidels and sends them to hell, making the survivors all the more hostile to Christianity. More often than not, crusades fail to meet their military goals, as the expedition of Louis IX so painfully illustrated. Bacon is not a complete pacifist; military defense of the Holy Land is legitimate, and he even suggests the use of high-tech mirrors to create fires in the enemy camp. But it is preaching and philosophical argument, not war, that will win converts to Christianity. — John V. Tolan, Saracens, 1144

Categorization

• XREF: Complicates the vault’s one-dimensional image of crusading as the sole medieval Islam-West mode; connects to Anidjar’s mapping of religious-secular oppositions.
• QUESTION: Bacon’s position that war ‘sends them to hell’ - how does the salvation-of-souls logic invert, rather than support, holy war? Worth tracing whether ‘convert or kill’ versus ‘convert by persuasion’ map onto later colonial debates.