Medieval art is ventriloquy. It distracts an audience, fully aware that the true voice is elsewhere, into believing that the oracle is actually present. The fourteen essays in Visible Truth focus on the ventriloquist's techniques. Among many topics, they discuss the consequences for art of Christianity's defining the ?people of the book? as strict adherents to the Second Commandment's prohibition of material representation, a strategy for appropriating Hebrew Scripture and reinterpreting to support physical images. Even though Jewish art also flourished during the Middle Ages, Christian came particularly to focus on materiality, artifice, experience, and emotional response to representations of Christ, whose own dual nature conducted provided a paradigm. They also attended to theories of vision and mechanisms of seeing ?mirrors, telescopes, surveyors' tools? as means for showing God to humans, whose sight, they believed, Adam's sin had weakened. As the essays in this volume argue, however, the line of sight art provided remained asymptotic to the Ineffable, who remained inapprehensible with the senses of the body, but glimpsed only through oculos mentis.