Steven French

Although much of its history has been neglected or misunderstood, a structuralist 'tendency' has re-emerged within the philosophy of science. Broadly speaking, it consists of two fundamental strands: on the one hand, there is the identification of structural commonalities between theories; on the other, there is the metaphysical decomposition of objects in structural terms. Both have been pressed into service for the realist cause: the former has been identified primarily with Worrall's 'epistemic' structural realism; the latter with Ladyman's 'ontic' form. And both raise important issues of general interest within the philosophy of science and metaphysics, respectively. The former invites questions regarding the identification and appropriate representation of these commonalities; the latter touches on different views regarding the nature of objects, the constitutive role of properties and the seat of causal powers. Both strands have recently come under critical fire. It is my intention to present a unified account of the 'structuralist tendency' which emphasizes the dual roles of structure as representational and constitutive, and to indicate how the more acute critical remarks can be dealt with

The current state of the relationship between metaphysics and the philosophy of science might appear to be one best described as ‘hostility on both sides’. In an attempt to bridge this gap, French and McKenzie have suggested a two fold strategy: on the one hand, if metaphysics is to be taken to have something direct to say about reality, the implications of physics need to be properly appreciated; on the other, one does not have to agree with the claim that a prioristic metaphysics should be dismissed or even discontinued, since we should value scientifically disinterested metaphysics as a ‘toolbox’ for philosophers of science. It is in the context of this strategy that I want to approach the issue of understanding the symmetry principles that feature in the Standard Model of modern physics. I shall suggest that the dispositional analysis of laws is incapable of accommodating such principles. However, there are other tools in the metaphysical toolbox that one can draw upon to help capture the nature of such symmetries corresponding to the second part of the above strategy.