I recently downloaded Hans Blumenberg, Quellen, Ströme, Eisberge as an ePUB publication (ISBN 9783518795804) from World of Digitals. It can only be read with Adobe Digital Editions and its restrictive license (no copying and no printing). Don't know whether I can recommend this format, aber "in der Not, frisst der Teufel Fliegen" ...
In any case, I don't want to comment on the format of the book, but on the Postscript and especially some information in the section on "The Syncretism of Slip boxes (Zettelkästen)" which describes Blumenberg's "workflow"—I hate that word—and his notes on Luhmann's "Communication with Slip Boxes." Apparently, he first carefully read a text, underlining important passages with a pen and a ruler. In some books he also included an index card with information when he read the book, how far he read it at a time, and when he continued reading it. He also had a notebook in which he noted the titles of books he read in chronological order. Quotes he found especially important he would transcribe to Index cards in the DinA 5 format, that is, the same format Luhmann used. However he used card stock, not paper sleeps, and he often typed the information. Using a stamp with continuous numbers, he would stamp each card as he finished it. Early on he would note that number at the appropriate place in the book itself. In addition to this, he listed every card numerically in separate lists (on separate cards?). Later, he abandoned this kind of meta-documentation. In addition to this, he noted what projects the notes were intended for.
Apparently, Blumenberg began his card index at the beginning of the the nineteen-forties. The editors conclude this on the basis of the condition of some of the cards and Blumenberg's own note in his copy of Luhmann's paper. More specifically he put the number "40" besides Luhmann's claim that he had already worked for 26 years on his slip box in 1981 (207).
He ended up with 30.000 cards. The cards with quotations he had used were marked by red slashes at the top and by dates (month and year) on the back. When a manuscript was finished, the used cards were put into marked envelopes marked "erl. KK"or or "finished index cards." Apparently the index cards formed "points of crystallization" or "Kristallisationskerne" (210). They often led to one-page manuscripts as an intermediate stage. He dictated many of his texts, having the index cards in front of him.
He also noted what he wrote in separate notebooks, thus tracing "input" and "output" (Blumenberg's own terms).
Blumenberg had to re-order his cards several times, depending on the purposes he had at a certain time. Luhmann never did. Whether that was an advantage may be doubted because repeated interaction with the material is more likely to stimulate revisions and growth over time. While Luhmann's work often is repetitious and not very elegantly formulated, Blumenberg's work is much more polished. However, both their texts reveal how they were put together, i.e. that they are accretions of more basic units. In some of his later books (and in the posthumous books) this shortcoming has become a virtue because Blumenberg now seems to write in aphorisms. In some sense, he always did.
Should anyone be interested, my slip box (in ConnectedText) has only 10.000 items or "topics" (with another 10.000 items in other projects), but I had a much later start. Nor will I ever have as much "output" as either Luhmann or Blumenberg, not to say anything about the importance.
1. The book also contains pictures of the various types of index cards Blumenberg used. The Marbach catalog (see next post) has more illustrations that show how he worked with the cards.