Van Fraassen’s view that many philosophical positions should be understood as stances rather than factual beliefs with propositional content, has become increasingly popular. But the precise relation between a philosophical stance, and the factual beliefs that typically accompany it, is an unresolved issue. It is widely accepted that no factual belief is sufficient for holding a particular stance, but some have argued that holding certain factual beliefs is nonetheless necessary for adopting a given stance. I argue against this claim, along (...) with the weaker claim that while there are no beliefs that are necessary for adopting a particular stance, those who share a stance must share some characteristic belief(s) in common. I outline and defend an alternative ‘cluster’ account, according to which, in order to accept a stance, one must hold some minimal subset of the set of theoretical beliefs characteristic of the stance in question. This view can accommodate the intuitions motivating those who defend the stronger necessity claims, while crucially allowing for the flexibility of a stance vis-à-vis the relevant factual beliefs, and its relative independence from those beliefs, which is central to van Fraassen’s main examples of stances and their nature. (shrink)

It is widely acknowledged that metaphysical assumptions, commitments and presuppositions play an important role in science. Yet according to the empiricist there is no place for metaphysics as traditionally understood in the scientific enterprise. In this paper I aim to take a first step towards reconciling these seemingly irreconcilable claims. In the first part of the paper I outline a conception of metaphysics and its relation to science that should be congenial to empiricists, motivated by van Fraassen’s work on ‘stances’. (...) There has been a considerable amount of recent work devoted to van Fraassen’s ‘stance’ view, but it has not on the whole been noticed that the view has the potential to motivate a general empiricist conception of the relation between science and metaphysics. In the second and third sections I discuss two examples from biology to illustrate this conception: metaphysical punctuationism, and its relation to and influence on the thesis of punctuated equilibrium; and dialectical biology as defended by Levins and Lewontin. (shrink)

Creationists have long argued that evolutionary science is committed to a dogmatic metaphysics of naturalism and materialism, which is based on faith or ideology rather than evidence. The standard response to this has been to insist that science is not committed to any such metaphysical doctrine, but only to a methodological version of naturalism, according to which science may only appeal to natural entities and processes. But this whole debate presupposes that there is a clear distinction between the natural and (...) the supernatural, and thus that naturalism is a meaningful doctrine. I argue that this assumption is false. The concepts of the natural and the supernatural are in fact hopelessly obscure, such that the claim that science is committed to methodological naturalism cannot be made good. This is no victory for anti-naturalists however; explicitly supernaturalist theories, such as Creationism, can be ruled out of scientific consideration as a priori incoherent, given that they presuppose for their intelligibility that there is a meaningful natural-supernatural distinction. This is not the case for standard scientific theories however, as they are not explicitly naturalistic theories; they do not postulate natural or physical entities or processes as such. (shrink)

Contemporary biology has inherited two key assumptions from the Modern Synthesis about the nature of population lineages: sexual reproduction is the exemplar for how individuals in population lineages inherit traits from their parents, and random mating is the exemplar for reproductive interaction. While these assumptions have been extremely fruitful for a number of fields, such as population genetics and phylogenetics, they are increasingly unviable for studying the full diversity and evolution of life. I introduce the “mixture” account of population lineages (...) that escapes these assumptions by dissolving the Modern Synthesis’s sharp line separating reproduction and development and characterizing reproductive integration in population lineages by the ephemerality of isolated subgroups rather than random mating. The mixture account provides a single criterion for reproductive integration that accommodates both sexual and asexual reproduction, unifying their treatment under Kevin de Queiroz’s generalized lineage concept of species. The account also provides a new basis for empirically assessing the effect of random mating as an idealization on the empirical adequacy of population genetic models. (shrink)