 Since Hartmann organized his bulky books into short chapters, subdivided into sections usually no longer than two or three pages, we follow his method of internal referencing by indicating the relevant chapters and sections. The following abbreviations will be used: ME = Grundzüge einer Metaphysik der Erkenntnis; S = “Systematische Philosophie in eigener Darstellung”; ET1 = Ethics (Volume 1: Moral Phenomena); ET2 = Ethics (Volume 2: Moral Values); ET3 = Ethics (Volume 3: Moral Freedom); P = Problem des geistigen Seins; OLF = Ontology: Laying the Foundations; PA = Possibility and Actuality; A = Der Aufbau der realen Welt; N = Philosophie der Natur; ELO = “Erkenntnis im Lichte der Ontologie”; NW = New Ways of Ontology; and AE = Aesthetics. The chapters of various Introductions will be referred to as “Intro”. For example, “NIntro5” and “N3c” will respectively refer to Section 5 of the Introduction and Chapter 3, Section c of the Philosophy of Nature. (These abbreviations are also included before the bibliography below.)