After decades of neglect philosophers of physics have discovered gauge theories--arguably the paradigm of modern field physics--as a genuine topic for foundational and philosophical research. Incidentally, in the last couple of years interest from the philosophy of physics in structural realism--in the eyes of its proponents the best suited realist position towards modern physics--has also raised. This paper tries to connect both topics and aims to show that structural realism gains further credence from an ontological analysis of gauge theories--in particular (...) U(1) gauge theory. In the first part of the paper the framework of fiber bundle gauge theories is briefly presented and the interpretation of local gauge symmetry will be examined. In the second part, an ontological underdetermination of gauge theories is carved out by considering the various kinds of non-locality involved in such typical effects as the Aharonov-Bohm effect. The analysis shows that the peculiar form of non-separability figuring in gauge theories is a variant of spatiotemporal holism and can be distinguished from quantum theoretic holism. In the last part of the paper the arguments for a gauge theoretic support of structural realism are laid out and discussed. (shrink)

(2000). CASSIRER, SCHLICK AND ‘STRUCTURAL’ REALISM: THE PHILOSOPHY OF THE EXACT SCIENCES IN THE BACKGROUND TO EARLY LOGICAL EMPIRICISM. British Journal for the History of Philosophy: Vol. 8, No. 1, pp. 71-106.

We outline Ladyman's 'metaphysical' or 'ontic' form of structuralrealism and defend it against various objections. Cao, in particular, has questioned theview of ontology presupposed by this approach and we argue that by reconceptualisingobjects in structural terms it offers the best hope for the realist in thecontext of modern physics.

This paper argues for a metaphysics of relations based on a characterization of quantum entanglement in terms of non-separability, thereby regarding entanglement as a sort of holism. By contrast to a radical metaphysics of relations, the position set out in this paper recognizes things that stand in the relations, but claims that, as far as the relations are concerned, there is no need for these things to have qualitative intrinsic properties underlying the relations. This position thus opposes a metaphysics of (...) individual things that are characterized by intrinsic properties. A principal problem of the latter position is that it seems that we cannot gain any knowledge of these properties insofar as they are intrinsic. Against this background, the rationale behind a metaphysics of relations is to avoid a gap between epistemology and metaphysics. (shrink)

This paper argues for a metaphysics of relations based on a characterization of quantum entanglement in terms of non-separability, thereby regarding entanglement as a sort of holism. By contrast to a radical metaphysics of relations, the position set out in this paper recognizes things that stand in the relations, but claims that, as far as the relations are concerned, there is no need for these things to have qualitative intrinsic properties underlying the relations. This position thus opposes a metaphysics of (...) individual things that are characterized by intrinsic properties. A principal problem of the latter position is that it seems that we cannot gain any knowledge of these properties insofar as they are intrinsic. Against this background, the rationale behind a metaphysics of relations is to avoid a gap between epistemology and metaphysics. (shrink)

In der Debatte um den wissenschaftlichen Realismus gewinnt zunehmend der Strukturenrealismus - dessen Auffassung zufolge der Realgehalt wissenschaftlicher Theorien in deren mathematisch-logischer Struktur liegt - an Bedeutung. Die vorliegende Arbeit untersucht diese These anhand der in unserer fundamentalen Physik bedeutsamsten Klasse von Theorien, den Eichtheorien, die durch spezielle lokale Symmetriestrukturen gekennzeichnet sind. Die Arbeit bietet dem Leser in ihren ersten Kapiteln einen Einstieg in die zentralen Themen Symmetrien, wissenschaftlicher Realismus und Eichtheorien. In den im Mittelteil durchgeführten Analysen werden Quanten- und (...) Gravitations-Eichtheorien in konzeptioneller Hinsicht - vor allem bezüglich der zugrundeliegenden Prinzipien - und ontologischer Hinsicht - mit Blick auf die Unterbestimmtheit der Entitäten und verschiedener Lokalitätsannahmen - im Detail untersucht. Resultierend ergibt sich eine Stützung des Strukturenrealismus, jedoch nicht in dessen radikaler ontischer Variante, sondern in der moderateren epistemischen oder allenfalls intermediären Spielart, bei der sowohl Strukturen als auch deren Träger existieren, wobei letzterer jedoch amorph und und mithin epistemisch unverfügbar ist. (shrink)