A certain famous philosopher from the 19th century made an arrangement of a few hundred of his notebook writings that was intended to be the outline for a book. He didn't live long enough to actually write the book, but some scholars are interested in working out what form it might have taken. This is because the arrangement is incomplete: it lists a bunch of texts and numbers them, and assigns about 2/3 to one of the four main divisions in an accompanying table of contents, but it doesn't specify which subdivisions they belong in, or how they should be ordered. Hence the scholarly speculation.
I'm working on a web app that would allow scholars to work on arrangements of these texts: basically assign them to sections, order them, etc. All of the texts I'm using are taken from an online scholarly edition of the author's works. Now these texts were written almost 150 years ago, and I'm using them in the original language, not in English translation, so I'm not infringing on the copyright of a more recent translation.
However, the online edition I took the texts from is basically a digitized version of the standard scholarly print edition, funded by a few major organizations. Because the author's originals were notebook material, the editors of this standard edition had to distill them into printable texts, which were never set in print that way by the original author.
My question is: does the publisher of the standard edition hold the copyright for their print renditions of these texts, or are their renditions public domain because the texts themselves were written so long ago? The author has been dead for well over 100 years.