Melinda Bonnie Fagan

This essay examines the role of social interactions in the search for blood stem cells, in a recent episode of biomedical research. Linked to mid-20th century cell biology, genetics and radiation research, the search for blood stem cells coalesced in the 1960s and took a developmental turn in the late 1980s, with significant ramifications for immunology, stem cell and cancer biology. Like much contemporary biomedical research, this line of inquiry exhibits a complex social structure and includes several prominent scientific successes, recognized as such by participating researchers. I use personal interviews and the published record to trace the social interactions crucial for scientific success in this episode. All recognized successes in this episode have two aspects: improved models of blood cell development, and new interfaces with other lines of research. The narrative of the search for blood stem cells thus yields a robust account of scientific success in practice, which generalizes to other scientific episodes and lends itself to expansion to include wider social contexts

In this paper, I propose a new way to integrate historical accounts of social interaction in scientific practice with philosophical examination of scientific knowledge. The relation between descriptive accounts of scientific practice, on the one hand, and normative accounts of scientific knowledge, on the other, is a vexed one. This vexatiousness is one instance of the gap between normative and descriptive domains. The general problem of the normative/descriptive divide takes striking and problematic form in the case of social aspects of scientific knowledge. With respect to this issue, history and philosophy of science appear starkly incompatible. I show how this dualism can be overcome, drawing on social action theory and the recent history of cellular immunology.

This review surveys three central issues in philosophy of stem cell biology: the nature of stem cells, stem cell experiments, and explanations of stem cell capacities. First, I argue that the fundamental question ‘what is a stem cell?’ has no single substantive answer. Instead, the core idea is explicated via an abstract model, which accounts for many features of stem cell experiments. The second part of this essay examines several of these features: uncertainty, model organisms, and manipulability. The results shed light on the form of our emerging knowledge of stem cells: mechanistic explanations. The third part of the essay sketches some key features of these explanations, which are constructed by a collaborative experimenting community

Epistemology of science is currently polarized. Descriptive accounts of the social aspects of science coexist uneasily with normative accounts of scientific knowledge. This tension leads students of science to privilege one of these important aspects over the other. I use an episode of recent immunology research to develop an integrative account of scientific inquiry that resolves the tension between sociality and epistemic success. The search for the hematopoietic stem cell (HSC) by members of Irving Weissman’s laboratory at Stanford University Medical Center exhibits both the goal-oriented character of contemporary immunology and the importance of social interactions in successful achievement of those goals. This episode includes three kinds of epistemic success: characterization of HSC, formation of new interdisciplinary interfaces, and reconciliation of apparently incompatible models. All three depend on coordinating the work of diverse participants via social interactions. Together, they reveal the crucial role of social interactions within and between research groups in producing epistemic success. These features of the search for the HSC generalize to immunology as a whole, and plausibly to other disciplines. This account thus resolves the polarizing tension in epistemology of science, and complements individualistic accounts of scientific knowledge and rationality.

This paper examines a case of failed interdisciplinary collaboration, between experimental stem cell research and theoretical systems biology. Recently, two groups of theoretical biologists have proposed dynamical systems models as a basis for understanding stem cells and their distinctive capacities. Experimental stem cell biologists, whose work focuses on manipulation of concrete cells, tissues and organisms, have largely ignored these proposals. I argue that ‘failure to communicate’ in this case is rooted in divergent views of explanation: the theoretically-inclined modelers are committed to a version of the covering-law view, while experimental stem cell biologists aim at mechanistic explanations. I propose a way to reconcile these two explanatory approaches to cell development, and discuss the significance of this result for interdisciplinary collaboration in systems biology and beyond