Is Scientific Theory-Commitment Doxastic or Practical?

Associated with Bayesianism is the claim that insofar as there is anything like scientific theory-commitment, it is not a doxastic commitment to the truth of the theory or any proposition involving the theory, but is rather an essentially practical commitment to behaving in accordance with a theory. While there are a number of a priori reasons to think that this should be true, there is strong a posteriori reason to think that it is not in fact true of current scientific practice. After outlining a feature that distinguishes doxastic from practical commitment, I present empirical evidence that suggests that, like perhaps all other theoretical commitment, scientific theory-commitment is doxastic. Scientific communities are defined by the general subject matter of the theories that they research and defend in their publications. It is to some set of these theories that the members of a community are committed. Commitment to contentful entities like theories can be either (i) a doxastic commitment to the truth of the theory or to some proposition about the theory, or (ii) a practical commitment to behaving in accordance with the theory. Which best characterizes an individual scientist’s or scientific community’s commitment? The contention in this paper is that there is some reason to think that it is contingently true that scientific theory commitment is generally a species of doxastic commitment. When an individual or community commits to a theory, that individual or the individuals that make up that community generally adopt a doxastic state. Much is at stake here. First, science is an extremely important institution to us, and one common and plausible view of its importance is that science is a good source of beliefs. We look to scientific experts to inform us about what the world is like with respect to many central aspects of our lives. We believe the theories to which scientists commit themselves, and we think that our beliefs are in better shape because of this.1 If it were to turn out that scientists do not themselves believe the theories that they accept, then our tendency to believe their commitments is in danger of being an inappropriate use of science. Secondly, the nature of theory-commitment affects those of us who study science as philosophers, historians, and sociologists. In what is no doubt a reflection of the previous point, the central issue of concern in the study of science is the nature of the processes that lead up to scientific theory-commitment. We spend our time studying the processes leading up Synthese 137: 325–344, 2003. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.