This double volume includes the indexes of the "Ferdinand Tönnies Study Edition" (table of contents, subject index, list of persons, etc.) as well as additional information about the underlying editorial principles, errata, the target audience, the relationship to the "Ferdinand Tönnies Complete Edition," and more.

The study edition was created as part of the documentation "Materials of the Ferdinand Tönnies Research Center" at the Alpen-Adria University Klagenfurt. It represents the more extensive main part of these materials: volumes 13 to 50. The first 12 volumes include preliminary work on this. Among other things, they contain considerations on possible design principles for the edition of a sociological collected works (relevance or chronology principle, target audience, intended function, etc.) as well as timely results from Tönnies research, some of which were later included in the book series "Tönnies in Conversation" if they had lasting relevance.

The Klagenfurt "Ferdinand Tönnies Study Edition" follows the relevance principle, meaning it is content-oriented around thematic focuses, such as in the "Political Writings" on the topic of World War I or in the "Writings on Thomas Hobbes" on his work, and consolidates them in one volume or across several volumes. In parallel, the chronologically oriented Kiel "Ferdinand Tönnies Complete Edition," published by the society of the same name, appears. Its volumes cover specific time periods, subdivided into monographs, writings, and reviews. Volume 7, for example, includes texts by Tönnies that he published in 1905 and 1906. Both editions cater to very different reading interests and can thus complement each other in various ways.