Vitruvius’s Ten Books of Architecture, the only architectural treatise to have survived from antiquity, was the fountainhead of architectural theory in the Italian Renaissance. Offering theoretical and practical solutions to a wide variety of architectural issues, this treatise did not, however, address all of the questions that were of concern to early modern architects. This study examines the Italian Renaissance architect’s efforts to negotiate between imitation and reinvention of classicism. Through a close reading of Vitruvius and texts written during the period 1400–1600, Alina Payne identifies ornament as the central issue around which much of this debate focused. Ornament, she argues, facilitated a dialogue across disciplines and invited exchanges with literary and rhetorical practices. Payne’s study also highlights the place of the architectural treatise in the text-based culture of the period and of architectural discourse in Renaissance thought.