I just found a radio interview (German) with André Kieserling, the professor who succeeded Luhmann, and who only recently opened the “Zettelkasten” for the first time after Luhmann’s death (link from the site of Daniel Lüdecke):

http://ondemand-mp3.dradio.de/podcast/2007/12/03/drk_20071203_1610_f40c7008.mp3

Some facts from this interview:

He describes the Zettelkasten as 6 boxes with 4 drawers each. They first tried to find with the help of an index, where certain slips are, and
that worked fine.

In parts the Zettelkasten can be read like a manuscript. There are
groups of “Zettel” that are not only next to eachother, but also share a common topic. There are slips to practically everything that later became a book. E.g. Luhmann has written a lot about organisations, and there are larger groups of slips that deal only with organisations. Other groups deal with religion, there are groups on many subjects, starting early in his carreer.

There are “Zettel” with whole sentences, and ones with notes in a few words. There are ones that are only drafts on topics he wants to research, and there are ones with whole sentences and paragraphs for several pages. There are e.g. 20 sheets on the leader in organisations, 30 on the role of the teacher, 15 about tests in schools.

The hanwriting can be read very easily, they just needed some time to get accustomed to it.

The reporter asks what Luhmann writes on the teacher in his Zettelkasten, and Kieserling answers, that he found the same things that Luhmann wrote in his books. He says that Luhmann alwasy said that he “pulled” his books out of the Kasten. And the “feeding” of the Zettelkasten was almost more work than the writing of his books. The writing was mainly the work of typing, and the real work was the care of the Zettelkasten. Kieserling says that these statements of Luhmann are backed up by what he found in the box.

The thinking of Luhmann, as reflected in the Zettelkasten, is one of interdisciplinarity. He read books from various subjects, from different eras in history, and made notes on it. It is a thinking of abstractions, and a sociological thinking, that has to take empirical facts into account.

A surprise was that the Zettelkasten contained very early records. There are two Zettel with the “number one”. One when he was 28 that pointed towards his scientific work, and another one a few years older, on things he might have read when he was about 20 years old.

When the legal questions are finally settled, the Zettelkasten will be scanned, so that the original is not endangered by using it, and published.

Marvelous! Your translation really helps to understand the “Zettelkasten”.

Did you know PoIC is taking German blood? I included Watanabe’s book in the Reference of PoIC manual. Now Luhmann’s case is second “German index cards” for me. I would like to know much more! :)

I have not followed the Taking Note link, but as a native speaker of German I get the following impression, that is a bit different from what you describe above:

Sheets are not completely free form: He states that for the one example sheet he handles in the beginning: It is a note he took at university, that he wants to integrate into his system. On the one side of the sheet there are the bibliographical data (it is some notes about an essay or article he has read) on the other side of the sheet there are notes on the content/ideas. He says the notes are “aus Anlass dieses Aufsatzes”, i.e. “notes on the occasion of the lecture of this essay”, not necessarily just excerpts, but maybe also his own thoughts when reading this text.

He says he has to make “Zettel” from this note, so it seems these less formal notes from university are somehow processed. He reworks these notes to be included into the Zettelkasten. Not only the citations and text excerpts he would have to copy afterwards, but also his thoughts, in what contexts this is. The text in the example is about Artificial Intelligence, about problem schema, a decision theoretical analysis that is applied to the Philosophy of Science.

He has picked out the sheets that are in the subject of “Philosophy of Science”, that is always the number 7.25 (He seems to mark his sheets in some kind of decimal classification, like the Dewey system). He points to a corner of the sheet (seems he writes 7.25 in a corner?)

He has added what he noted on the one sheet he brought from university to the others on Philosophy of Science already in his Zettelkasten. This seems to be not only copying but also reworking, rephrasing. Afterwards it goes back into the Zettelkasten.

He stresses, that he always has to be careful to put them at the correct location, because once they are misplaced, the sheets can be found “by accident” only. He always checks afterwards, that he has put the sheets back at the right place, because that is the problem with his system, he says. While the voiceover starts he puts back another collection of Zettel he had taken out, because he originally. wanted to add his notes to another topic first.

Hope that helps, feel free to ask if you need any help with similar German videos or texts!

BTW Niklas Luhmann is a very highly regarded person of German cultural life. His theories (as also the voiceover says) are sometimes criticised as too conservative, but together with Jürgen Habermas he is certainly a central figure in Sociology, especially theory of society.