The aim of this volume is to collect papers that situate, discuss and critically asses David Armstrong's contributions. The book is organized in three parts. In Section I: Analytical Metaphysics and Its Methodology, certain basic principles of analytic metaphysics advocated by Armstrong and their consequences are critically examined. The articles of Section II: Laws of Nature, Dispositions, and Modality, study the constraints Armstrong's naturalism sets to his ontology of modality, laws and dispositions. Finally, the articles of Section III: Mind and Epistemology, study and critically evaluate Armstrong's contributions in epistemology, the philosophy of perception and color.