A series of targeted sorties into the source material

 

"The earliest depiction of spectacles [eyeglasses] in a painted work of art occurs in a series of frescoes dated 1352 by Tommaso da Modena in the Chapter House of the Seminario attached to the Basilica San NicoloOffsite Link in Treviso, north of Venice. Cardinal Hugo of Provence [Hugh de St. Cher] is shown at his writing desk wearing a pair of rivet spectacles that appear to stay in place on the nose without additional support. The Cardinal actually died in the 1260s and could never have worn spectacles! link

From "Index, History of"

[Bishop of London, Glbert Foliot speaks in a lecture].  Foliot begins with an analogy: Christ is like a stone. To illustrate the point, Foliot proceeds to run through a list of biblical stones, from Psalm 118 ('The stone which the builders refused is become the headstone of the corner") and the stone that Jacob uses as a pillow (Genesis 28:10-22) to the stone that smashes the false gods in Nebuchadnezzer's dream (Daniel 2:34-35).  At each stage, Foliot pauses, drawing out the metaphorical implications of these different instances, using each toto shine a new light on his opening analogy, enriching it by viewing it from a variety of angles....

When Peter of Cornwall heard Foliot speak, he was so inspired that he began to compile his own immense collection of distinctiones as an aid for preachers. At around a million words in length, Peter's Pantheologus may look like a daunting read today, but it would be wrong to imagine that this would have been the case for its earliest users.... distinctiones implicitly say something further about reading; they expect us to read other books in extract form as well. Far from the deliberate monotony of the monastic reading drill, of a lifetime spent patiently working and reworking one's way through the Bible, each distinctio sends its user on a series of targeted sorties into the source material - a phrase from the Psalms; maybe an image from one of the Gospels; a moment in Genesis....

The distinctio-collection, then, is evidence of a a type of reading that might be thought of as indexical.  A table of contents, as we saw in the Introduction, respects and reflects the order of the book to come. If you read from start to finish, it says, this is what you weill encounter and when you will encounter it.  The index, on the other hand, has nothing to say about orderly reading.  In fact, if we wanted to reconstruct a book's sequencing from its index, we would need a spreadsheet and an awful lot of patience...

...

Amounting to roughly 600 entries and running in alphabetical order from Abel to Zelus, Peter's collection explodes each of its topics into a sort of primite tree diagram. Take, for example, the topic Abyssus, meaning (depth). Here the rubricated headword gives onto five wavy lines, each one leading to a distinct sense in which the term might be understood -- the depth of God's justice, or the depth of men's hearts -- follwed by the gobbet of scripture from which this particular sense is drawn: 'He layeth up the depth [abyssos] in storehouses' (Psalms 33:7), 'Deep [abyssus] calleth unto deep [abyssum]' (Psalm 42:7), and so on.  It is not hard to imagine this as a preaching aid for a sermon like Foliot's: a visual aid, more memorable than a paragraph of text.