One of Leonardo da Vinci's most famous and most debated paintings is his late 15th century fresco "The Last Supper." Placed throughout the composition are various symbols with meanings that remain controversial and uncertain to this day. For centuries, scholars and art historians alike have tried to uncover what exactly Leonardo was trying to say to his audience in this exceptional work. In this first installment of Patheos' new series on Art and Religion, we look at...