The aim of this article is to make a case for the pertinence of a biographical approach to the history of scientific objects. I first lay out the rationale of that approach by revisiting and extending my earlier work on the topic. I consider the characteristics of scientific objects that motivate the biographical metaphor, and I indicate its virtues and limitations by bringing out the positive and negative analogies between biographies of scientific objects and ordinary biographies. I then point out various ways in which scientific objects may pass away and argue that their demise should be conceptualized as a process. Finally, I sketch the history of the concept of “ether” in nineteenth and early twentieth century physics and suggest that it lends itself particularly well to a biographical treatment. To that effect, I discuss the identity, heuristic character, and recalcitrance of the ether and examine the reasons that may have led to its passing.

In this paper, we employ Ian Hacking’s insight that ‘‘unity’’ has a double meaning, singleness and harmonious integration, to revisit a major episode from the recent history of CERN: the UA1 and UA2 experiments in the early 1980s, which led to the discovery of the W and Z bosons. CERN is a complex institution, where diverse groups are called upon to cooperate. We argue that this lack of unity, in the first sense of the term, is counterbalanced by specific mechanisms of integration, so that CERN achieves its standing as a unified organization. The UA1/UA2 episode highlights this interplay between unity and disunity. The UA2 experiment was designed and carried out in order to confirm the validity of the results obtained by UA1. The two experimental teams, working independently and with different mentalities, built separate detectors and refrained from systematically sharing their data. This gave rise to strong antagonisms and diametrically opposed opinions over what conclusions could legitimately be drawn from the resulting data. Our analysis focuses on the mechanisms which compensated for that disunity and eventually led to a unified consensus between UA1 and UA2.

In this paper we attempt a critical appraisal of the relation between history of science and philosophy of science in Ian Hacking’s styles of scientific reasoning project. In our analysis, we employ a distinction between “historical philosophy of science” and “philosophical history of science”: the former aims at addressing philosophical issues, while the latter aims at telling stories about the scientific past that are informed by philosophical considerations. We argue that Hacking practices historical philosophy of science; discuss how his approach is differentiated from the so-called confrontation model; and show that he opts for a strong integration between history and philosophy of science. Finally, we discuss the historiographical implications of his approach and suggest that his aim to maintain a middle position, on the one hand, between contingency and inevitabilism, and, on the other, between internalism and externalism in the explanation of the stability of scientific knowledge, is compromised by his philosophical commitments.