What things count as individuals, and how do we individuate them? It is a classic philosophical question often tackled from the perspective of analytic metaphysics. This volume proposes that there is another channel by which to approach individuation - from that of scientific practices. From this perspective, the question then becomes: How do scientists individuate things and, therefore, count them as individuals? This volume collects the work of philosophers of science to engage with this central philosophical conundrum from a new angle, highlighting the crucial topic of experimental individuation and building upon recent, pioneering work in the philosophy of science. An introductory chapter foregrounds the problem of individuation, arguing it should be considered prior to the topic of individuality. The following chapters address individuation and individuality from a variety of perspectives, with prominent themes being the importance of experimentation, individuation as a process, and pluralism in individuation's criteria. Contributions examine individuation in a wide range of sciences, including stem cell biology, particle physics, and community ecology. Other chapters examine the metaphysics of individuation, its bearing on realism/antirealism debates, and interrogate epistemic aspects of individuation in scientific practice. In exploring individuation from the philosophy of biology, physics, and other scientific subjects, this volume ultimately argues for the possibility of several criteria of individuation, upending the tenets of traditional metaphysics. It provides insights for philosophers of science, but also for scientists interested in the conceptual foundations of their work.

What is a stem cell? The answer is seemingly obvious: a cell that is also a stem, or point of origin, for something else. Upon closer examination, however, this combination of ideas leads directly to fundamental questions about biological development. A cell is a basic category of living thing; a fundamental 'unit of life.' A stem is a site of growth; an active source that supports or gives rise to something else. Both concepts are deeply rooted in biological thought, with rich and complex histories. The idea of a stem cell unites them, but the union is neither simple nor straightforward. This book traces the origins of the stem cell concept, its use in stem cell research today, and implications of the idea for stem cell experiments, their concrete results, and hoped-for clinical advances.