This article is intended to contribute to the discussion of the topicality and historical and theoretical limitations of Koselleck’s theory. The concept of acceleration, which has a special meaning for Koselleck, both in terms of conceptual history and social theory, will serve as a guide to this investigation. Since it is a socio- and temporal-analytical concept, the current thesis, that we have entered a post-Koselleckian culture, should be amenable to testing on the basis of this concept, which this article will (...) consider in some detail. The examination is divided into three parts: The first part addresses the concept of acceleration and its implications for Koselleck. On the basis of the results of the first part, the second part discusses issues and problems that go beyond Koselleck’s approach, and/or show it’s theoretical or methodological limits. Finally, the third part summarizes the conclusions of the foregoing examination, and emphasizes the problem-historical continuity with Koselleck’s inquiry into a socio-historically informed history of concepts. (shrink)