St. Francis of Assisi today is often thought of in revolutionary, avant-garde images: the merchant’s son who stripped naked in public to renounce his worldly possessions and attachments, the mystic who preached to the birds, the friar who embraced lepers, and the erstwhile evangelist who crossed enemy lines during a crusade to preach to a sultan. St. Francis indeed was all these things. But as for the St. Francis who lamented abuses of the liturgy, submitted to Church authority, displayed the utmost respect for the clergy, and also debated the meaning of the gospels with the same sultan—we don’t hear...