What is it for an object to persist through time? Do things have essences? What is the relation between an object and its parts? Are objects more real than their parts, or vice versa? Could there be spatio-temporally coincident objects? Do we need an ontology of truth-makers? These interrelated questions reflect the central concerns of contemporary metaphysics, which in recent years has seen an intensification of interest in ontological issues. They are the focus of the essays collected in this volume, which arose from the Being: Developments in Contemporary Metaphysics conference held at the University of Leeds in September, 2006.