Book excerpt: The contributions to the "Thirty Years Volume" represented in this volume reflect the historical focus of the ProtoSociology project. Colleagues are represented who contributed to the focus. This is also true thematically, as contributions on language theory, the philosophy of the mental, and the sociology of contemporary societies are represented. The contributions to the "Thirty Years Volume" are definitely evidence that they address central research problems of ProtoSociology, regardless of their particular epistemological interests.