1 Ian Hacking’s Metahistory of Science Manolis Simos and Theodore Arabatzis Department of History and Philosophy of Science National and Kapodistrian University of Athens 1. Introduction This paper aims at a critical appraisal of the relation between history of science and philosophy of science in Ian Hacking’s work. Specifically, we focus on the series of essays that comprise his styles of scientific reasoning project and examine his theoretical reflections on that relation. In these essays, Hacking provides us with elaborate metahistorical reflections: theoretical reflections on the relation between philosophy and history, and on his own philosophical and historical practice, that is, on his own way of practicing philosophy and history, or, better, philosophy cum history. Our approach to these reflections is guided by three closely interrelated research questions. First, we focus on Hacking’s theoretical stance on the relation between history of science and philosophy of science. This question takes the form of an inquiry concerning whether Hacking’s approach constitutes a ‘historical philosophy of science’ or ‘a philosophical history of science’. The former aims at elucidating or taking a stance on philosophical issues by drawing upon historical material, while the latter aims at telling stories about the scientific past that are informed by conceptual and philosophical considerations. 1 In discussing this question, providing textual evidence and interpretative justification, we argue that Hacking self- reflectively practices ‘historical philosophy of science’; that is, he articulates a philosophical stance in response to philosophical issues and he argues for it historically. 2 Second, we argue that Hacking is differentiated from the so-called confrontation model in history and philosophy of science (HPS), and we sketch the alternative integrative approach he suggests. As we discuss in the next section, after the critique of logical positivism in the 1960s and 1970s, the resulting turn to a 1 See Arabatzis 2017. 2 For a different approach to how Hacking understands the relation between history and philosophy, see Kindi 2014.