Conventional and Objective Invariance: Debs and Redhead on Symmetry

This review is a critical discussion of three main claims in Debs and Redhead’s thought-provoking book Objectivity, Invariance, and Convention. These claims are: (i) Social acts impinge upon formal aspects of scientific representation; (ii) symmetries introduce the need for conventional choice; (iii) perspectival symmetry is a necessary and sufficient condition for objectivity, while symmetry simpliciter fails to be necessary. Much work in the philosophy of science falls into one of two camps. On the one hand, we have the system builders. Often with the help of formal methods, these philosophers aim at a general account of theories and models, explanation and confirmation, scientific theory change, and so on. Here, examples from the sciences are at best illustrations of the philosophical claims in question. On the other hand, we find those philosophers who, dissatisfied by general accounts and often prompted by a close study of the history of science, present detailed accounts of very specific parts of science, without aiming at the development of a general account. If a general account of science is referred to at all, it is refuted (by a case study) or only used to describe a certain episode of scientific research. Although both of these approaches have their merits and limitations, very few research projects span the whole range of philosophy of science, such that results from general accounts are non-trivially applied to case studies of specific sciences. It is a virtue of Debs and Redhead’s book (2007, page numbers refer to this work) that they ∗Theoretical Philosophy Unit, Utrecht University, The Netherlands †Tilburg Center for Logic and Philosophy of Science, Tilburg University, The Netherlands