Philosophers have usually highlighted how the weakness and paucity of historical evidence underdetermine the choice between rival historical explanations. Focusing underdetermination on the link between theory and evidence comes, I argue, with three assumptions: competing hypotheses are easy to generate, investigators agree on the constitution and interpretation of the evidence and a plurality of hypotheses is a useful evil to reach consensus. The last assumption implies that the sustained coexistence of incompatible hypotheses is considered as a scientific failure. I argue (...) that this negative vision of sustained disagreement has monistic undertones. By drawing from a case study in evolutionary biology, this paper defends a form of scientific pluralism. Firstly, I show that underdetermination is not only found at the inferential level but also at the level of the constitution and interpretation of the evidence, on the choice of investigative scaffolds and when interpreting background theories. Because of that, competing hypotheses exhibit a degree of methodological incommensurability. While catastrophic from a monistic standpoint, I defend that scientific pluralism gives a different, and I think richer, account of such situations. On the plus side, competing approaches benefit from their sustained coexistence and interaction. I argue that this generates direct and indirect epistemic goods independently of whether the controversy is solved. Scientific pluralism also shifts our attention from achieving consensus to managing disagreement. The challenge becomes to maintain the conditions for fruitful interactions in a community with incommensurable approaches and heterogeneous expertise. (shrink)

(Recipient of the 2020 Everett Mendelsohn Prize.) This article revisits the development of the protoplasm concept as it originally arose from critiques of the cell theory, and examines how the term “protoplasm” transformed from a botanical term of art in the 1840s to the so-called “living substance” and “the physical basis of life” two decades later. I show that there were two major shifts in biological materialism that needed to occur before protoplasm theory could be elevated to have equal status (...) with cell theory in the nineteenth century. First, I argue that biologists had to accept that life could inhere in matter alone, regardless of form. Second, I argue that in the 1840s, ideas of what formless, biological matter was capable of dramatically changed: going from a “coagulation paradigm” that had existed since Theophrastus, to a more robust conception of matter that was itself capable of movement and self-maintenance. In addition to revisiting Schleiden and Schwann’s original writings on cell theory, this article looks especially closely at Hugo von Mohl’s definition of the protoplasm concept in 1846, how it differed from his primordial utricle theory of cell structure two years earlier. This article draws on Lakoff and Johnson’s theory of “ontological metaphors” to show that the cell, primordial utricle, and protoplasm can be understood as material container, object, and substance, and that these overlapping distinctions help explain the chaotic and confusing early history of cell theory. (shrink)

The question ‘what is life?’ has long been a source of philosophical debate and in recent years has taken on increasing scientific importance. The most popular approach among both philosophers and scientists for answering this question is to provide a “definition” of life. In this article I explore a variety of different definitional approaches, both traditional and non-traditional, that have been used to “define” life. I argue that all of them are deeply flawed. It is my contention that a scientifically (...) compelling understanding of the nature of life presupposes an empirically adequate scientific theory (vs. definition) of life; as I argue, scientific theories are not the sort of thing that can be encapsulated in definitions. Unfortunately, as I also discuss, scientists are currently in no position to formulate even a tentative version of such a theory. Recent discoveries in biology and biochemistry have revealed that familiar Earth life represents a single example that may not be representative of life. If this is the case, life on Earth today provides an empirically inadequate foundation for theorizing about life considered generally. I sketch a strategy for procuring the needed additional examples of life without the guidance of a definition or theory of life, and close with an application to NASA’s fledgling search for extraterrestrial life. (shrink)