The anonymous Speculum de mysteriis ecclesiae from the 12th century abbey of St. Victor has often been associated with the tradition of medieval liturgical commentaries, but this dissertation proposes reading it primarily as a general treatise on the spiritual life. Its unique Victorine emphasis on the combination of intellect and affect suggests a particular theology of the sign: the real ontological status of the sign relying not on Dionysian hierarchy but on ecclesial contemplation. Through the newly developed sacramental understanding of res et sacramentum, the Speculum suggests that signs have enduring value as signs that goes beyond their function as signifiers. The attainment of the signified, in other words, is only part of their gift. Their “sweetness” is found in an appreciation of their mode of signification — a signification that, the Speculum suggests, endures somehow even in heaven as a non-necessary gracious source of delight. That is, external and visible things in the Church have value not merely because they point us to particular invisible things (what the signs “mean”) but because they teach us the Church’s economy of grace. The Church, then, and her sacramental economy, are central not just to the practical life of individual salvation, but to the meaningfulness of all creation.