Epistemology, as generally understood by philosophers of science, is rather remote from the history of science and from historical concerns in general. Rheinberger shows that, from the late nineteenth through the late twentieth century, a parallel, alternative discourse sought to come to terms with the rather fundamental experience of the thoroughgoing scientific changes brought on by the revolution in physics. Philosophers of science and historians of science alike contributed their share to what this essay describes as an ongoing quest to historicize epistemology. Historical epistemology, in this sense, is not so concerned with the knowing subject and its mental capacities. Rather, it envisages science as an ongoing cultural endeavor and tries to assess the conditions under which the sciences in all their diversity take shape and change over time. Throughout the book, Rheinberger traces the themes of historical contingency, the role of technology, and the plurality of the sciences. These themes are well familiar from Rheinberger's own version of historical epistemology as presented inTowards a History of Epistemic Things. On Historicizing Epistemologythus gives us a helpful overview over those thinkers and positions that are central for Rheinberger's own systematic thinking. In this small book, Rheinberger proposes the highly interesting thesis that the history of the discipline of the history of science has been animated, above all, by an inquiry into the historical dimension of knowledge and of scientific inquiry.On Historicizing Epistemologyis a wonderful introduction to the history of the sciences, but also to the conception of a 'historical epistemology,' which is Rheinberger's most valuable contribution to the development and rethinking of the discipline. Hans-J?rg Rheinberger is Director of the Max Planck Institute for the History of Science in Berlin. He is the author ofToward a History of Epistemic Things: Synthesizing Proteins in the TlS‹