This is Suger of Saint-Denis's great work on the decoration of the church; it survives only in fragments, but what we have is fascinating:
On What Was Done in His Administration
Suger of Saint-Denis, by the way, was the person who succeeded the abbot of Saint-Denis who appears as a villain in Abelard's story (whose name was Adam, if I remember correctly). When Suger became abbot, he began an extensive set of reforms, of which the projects mentioned in the above fragment were a part. Suger's administration was of massive importance for the history of architecture; the first rise of a clearly Gothic design appears to have been his re-construction of the abbey church. Some elements of Gothic pre-date it; some elements came later; but the basic approach is fully developed here. Readers of Umberto Eco's The Name of the Rose will find Section XXIII somewhat familiar: the discussion of gems by the abbot in Eco's book is a cynical modification of the thought of this section. But Suger, unlike Eco's abbot, seems to take very seriously the anagogy of decoration, the means by which the beauty of the Church is intended to be an earthly echo reminding people of the glory of heaven. Eco's abbot, of course, seems to use it merely as an excuse for fleshly indulgence, and it's an obvious danger in what Suger was doing. But it's also clear that there is something to this doctrine of anagogy.
You can see some of Suger's windows (discussed in Section XXXIV) here. Here is a chalice acquired by him.
