Diagrams in English medieval manuscripts.
This thesis examines diagrams found in English medieval manuscripts dating from the ninth to
the fourteenth century. It is based upon a survey of diagrammatic material, the results of which
are presented in the catalogue raisonnee (Appendix A). The lack of adequate terms to define
diagrams is addressed, as is the lack of a consistent and coherent treatment of diagrams in
existing literature. A close critique of diagrams can be an aid in dating manuscripts and tracing
textual recensions, and therefore a well-defined yet flexible framework must be established in
order to further future research. The catalogue establishes standard types for particular
diagrams, which can be used for comparison and identification of examples in manuscripts.
The discussion of the thesis is largely structured on a chronological basis, studying the types of
diagrams which were in use in three periods; late Antiquity, the Dark Ages, and the twelfth to
fourteenth centuries. The main diagrammatic forms which were transmitted from late classical
commentaries in medieval manuscripts are analysed in terms of their content and technique.
These diagrams are still influenced by Greek learning. Changes and adaptations in these forms
and techniques are then observed. The degeneracy of learning in the Dark Ages is characterised
by diagrams based on cyclical rather than circular forms. The availability of translations of
Greek texts through Arab sources in the twelfth century leads again to precise diagrams which
accompany logical textual exposition.
Diagrams are finally viewed within the wider context of medieval art. Features of medieval
aesthetics are highlighted which make it possible to approach diagrams in the same way as
works of art. The importance of geometric structures to artistic composition is increased by the
symbolic meanings which are attached to certain shapes and proportions. Pictorial diagrams
themselves migrate into wall-paintings and floor-mosaics, and also eventually into literature