The employment of diagrams in religious education gained impetus from the new exegetical methods being developed in cathedral and monastic schools during the eleventh and twelfth centuries. Biblical exegesis was evolving from the simple historical/allegorical division established by such early Christian thinkers as Clement of Alexandria and Origen to analysis that had three and even four levels. The complexity of teaching these systems made the diagrammatic presentation of material desirable. Visual depictions transcended the limitations of textual learning. When the student viewed a diagram, he was able to take in all meanings attributed to it in one glance. Thus, he was liberated from the temporality of text, where what had already been read was past and what was to come was still unknown. Diagrammatic presentation unified the exegetical process, enabling the viewer to learn more quickly and more assuredly the three or four levels being presented in the lesson.
In the books produced to teach the new exegesis, images began to take on an increasingly significant role. While in some cases a visual representation preceded an exegetical text as a summary of what was being taught, at other times it was the primary focus, with the text merely serving as an introduction for that which was taught via the image and its inscriptions.
The twelfth-century Parisian master Hugh of St. Victor seems to have been a particular advocate of diagrammatic pedagogy, and some scholars believe that his works treating the meanings of Noah's Ark were rooted in a figure that is now lost to us. For Hugh the image was closer to the thing itself because it was a direct depiction of reality. On the other hand, written words were translations of experiential data into a set of signs visually dissimilar from physical phenomena encountered by the eyes. Thus, the diagram was not an abstract representation of a set of truths but rather an approximation of its concrete manifestation.
Hugh believed that the visual representation was purified of its gross physical being in the imagination before being passed on to the soul. With this transference, the essence of the image, its relationship to the truths of God, could be assessed rationally and reflected upon ethically. In visual exegesis image perception was refined into spiritual understanding, enabling the viewer to climb from the corporeal to God and divine things.