Externalism, Naturalism, Mathematics, Ontology, Personal Identity, Time and Tense, The Metaphysics of Reference, The Metaphysics of Properties, Conceivability, The Physical, and Theoretical Identity, and Actualism- these are some of the central issues addressed in the essays of this fifteenth volume devoted to metaphysics. * Essays discussing metaphysics from some of the foremost academics in philosophy. * Topics include Ontology, Personal Identity, the metaphysics of reference, and the metaphysics of properties.