Martin → chrisaldrich Yes, Chris, I even came across this site. Porstmanns Karteikunde was actually the publication that inspired my early Zettelkasten activities back when I was still a schoolboy, nearly half a century ago. And of course, Luhmann would have learned this kind of administrative practice in his first job, since it was widely used in offices at the time. I’ve always wondered whether he ever taught anything about it while working in Speyer.

eaving the civil service in 1962, he lectured at the national Deutsche Hochschule für Verwaltungswissenschaften (University for Administrative Sciences) in Speyer, Germany.[6]