Chapter 1: The Implications of General Covariance for the Ontology and Ideology of Spacetime

It generally agreed that the requirement of formal general covariance (i.e. the demand that laws be written in a form that is covariant under arbitrary coordinate transformation) is a condition of the well-formedness of a spacetime theory and not a restriction on its content. Physicists commonly take the substantive requirement of general covariance to mean that the laws exhibit diffeomorphism invariance and that this invariance is a gauge symmetry. This latter requirement does place restrictions on the content of a spacetime theory. The present paper explores the implications of these restrictions for interpreting the ideology and ontology of classical general relativity theory and loop quantum gravity