At the heart of my pragmatic theory of truth and ontology is a view of the relation between language and reality which I term internal justification: a way of explaining how sentences may have truth-values which we cannot discover without invoking the need for the mystery of a correspondence relation. The epistemology upon which the theory depend~ is fallibilist and holistic (chapter 2); places heavy reliance on modal idioms (chapter 4); and leads to the conclusion that current versions of realism and anti-realism are deficient (chapter 5). Just as my theory avoids the need for an epistemic 'given', it avoids the need for a metaphysical 'given' or 'joints'. I offer a view of the nature of philosophy and what it can properly achieve with respect to ontological questions (chapter 3); since those views lead me to believe that philosophical discussion about what exists should be restricted to 'entities' discussed in non-philosophical contexts, my views on how we should understand claims made about the existence of middle-sized physical objects (chapters 2 and 6), theoretical entities in science (chapter 6), and abstract entities in mathematics (chapter 7), give the thesis a schematic completeness. My theory leads me to a conception of inquiry which defends the cognitive status of moral statements whilst being critical of Kantian and utilitarian approaches to morality (chapter 8). Chapter 1 explores the views of my closest philosophical allies: William James and Nelson Goodman.