There is a description of the old Georg Wilhelm Friedrich Hegel, which says that he "sat at a very broad writing desk, and presently dug around impatiently in an disorderly stacked and scrambled heap of books and papers. Not the picture of "the most systematic of the post-Kantian idealists" that one might expect, though in some sense perhaps really more representative of the systematicity of of his system than this quote from the Stanford Encyclopedia of Philosophy. There is a difference between intent and finished or unfinished product—whatever the case may be.
It appears that part of the problem was that Hegel never settled on one unified system of note-taking, as someone like Luhmann clearly did. At times, Hegel used the method of note-books or "wastebooks," as they were called in the eighteenth and early nineteenth century. So there are "Aphorisms from the Wastebook." He also used interleaved books, that is, books bound with empty pages on which to write. We know this about at least about one of his own books. And he also used the manuscripts for his lectures for further notes.
But, most interestingly, he had—early in his life—developed a system of note-taking, which is described by his own sister as follows: "He approached his reading as follows: Everything that seemed remarkable to him he wrote on a separate sheet of paper, which he identified at the top by a general label under which the particular content had to be subsumed. In the center of the upper edge he then wrote in large letters—not infrequently using Fraktur letters—the keyword of the article. These pages he ordered alphabetically ... and thus could by means of this simple method use his excerpts at any moment. During all his moves, he kept these incunables of his education partly in maps, partly in writing folders, on whose spines he glued labels for orientation.
Some people have described this as a Zettelkasten. But this is clearly misleading. They represent a system of maps as described by someone like Blumenbach, for instance.
Even if Hegel's Phenomenology has sometimes the appearance of a Zettelkasten, it was probably based on the system of maps. Too bad Hegel did not stay with this system, for it appears to me that the Phenomenology is his strongest book.
1. "Er saß vor einem breiten Schreibtische und wühlte soeben in ungeduldig in unordentlich übereinandergeschichteten, durcheinandergeworfenenen Büchern und Papieren."
2. See also the so-called "Frankfurter Notizen," for instance.
3. "Bei seiner Lektüre ging er nun folgendermaßen zu Werke: Alles, was ihm bemerkenswert schien, schrieb er auf ein einezlnes Blatt, welches er oberhalb mit einer allgemeinen Rubrik bezeichnete, unter welchen der besondere Inhalt subsumiert werden mußte. In die Mitte des oberen Randes schrieb er dann mit großen buchstaben, nicht selten mit Frakturschrift das Stichwort des Artikels. Diese Blätter ornete er für sich wieder nach dem alphabet und war mittelst dieser einfachen Vorrichtung im stande, seine Exzerpte jeden Augenblick zu benutzen. Bei allem Umherziehn hat er diese Inkunabeln seiner Bildung immer aufbewahrt. Sie liegen teils in Mappen, teils in Schreibfutteralen, denen auf dem Rücken eine orientierende Etikette aufgeklebt ist." Joh. Hoffmeister, Dokumente zu Hegels Entwicklung, 1936, p. 398.