Nietzsche is a pragmatist with strong resonances with the American pragmatists; this is not a new claim. Renè Berthelot, for instance, termed Nietzsche “a German pragmatist” and emphasized the resemblance between Nietzsche’s perspectivism and the pragmatist theory of truth. The resemblance between Nietzsche and the American pragmatists  is made especial note of in Arthur Danto‘s Nietzsche as Philosopher, which bids us examine The Gay Science. There, as Danto notes, Nietzsche claims that “we `know’…just as much as may be useful in the interest of the human herd” and that our primary epistemic concern is “how far a belief furthers and supports life, maintains and disciplines a species.” Nietzsche’s epistemological strategy has clear entailments for his ontology: what we believe exists is a function of how useful that belief is; metaphysics and epistemology are inseparable. Questions of ontology for Nietzsche are questions of human interests; they do not address the ‘ultimate nature of being,’ to anything unconditioned, to “something which would be true, absolutely and unconditionally, outside of all temporal and perspectival conditions.”
For Nietzsche, perspectives, interpretations, constitute our epistemological relationships with the world completely, rendering talk of distortions of reality unintelligible. Thus, marking the beginning point for pragmatic evaluations of theoretical formulations, our dominant perspective and its attendant ontology are the most “useful and necessary.” Morality and our moral theories too, allow a life-preserving way of living and interacting with this world. Morality becomes one of our many perspectives; but there are no moral phenomena or facts—all we have are “moralistic interpretations of phenomena.” Nietzsche thus dismisses the fact-value distinction—as a pragmatist might—because there are no facts, only interpretations guided by our interest-driven values. Such values come to constitute our sense of ourselves for “evaluation is creation.”
As Danto notes, Nietzsche claims there is “an inescapable tendency on our part to posit entities—to think in terms of things—and to regard the world as characterized by ‘unity, identity, permanence, substance, cause [and effect], thinghood and being.” This positing tendency, the hallmark of theory construction, leads to perspectives which speak of, and manipulate these entities in their claims; these perspectives are sustained by their success in helping achieve our ends; utilizing these concepts ‘works for us’ in furthering our collectively determined ends.
Nietzsche’s perspectivism entails all terms are theoretical. The supposed contrast between theoretical terms and constructs and the objects of ‘common sense’ now vanishes; the solid object we bump up against is a theoretical posit within the perspective termed ‘common sense.’ We construct a world and its attendant reality—for ourselves, the theory’s proponents—by constructing a theoretical world indispensable for the forms of life we lead. The acceptance of these ‘articles of faith’ and their indispensability hints at the theoretical resilience of these entities. Nietzsche thus urges a pragmatic understanding of concepts like ‘cause’ and ‘effect’ as “conventional fictions.” Concepts are creative, ways by which we can fashion a new being, a new form of life.
Nietzsche’s perspectivism—human needs constitute the world for us—rejects metaphysical realism, preferring a view in which a dynamic always-becoming world is theorized into a form suited to our purposes. Perspectives are interpretations; they make some statements true and not others but none is privileged–absolutely–above the others. In Nietzsche’s ontological view “the world is a mere fiction, constructed of fictitious entities” (The Will to Power, 568); these entities are invented to suit our ends. The entities Nietzsche considers ‘fictitious’ includes “substance, soul, (ego, philosophical subject), synchronic and diachronic identity, being, thing, cause and effect, duration, and materiality.” Our language—a theory with its theoretical terms, its ‘fictions’—is a function of our means and ends and interests and bears the mark of our social activities and organizations, its service of particular ends and ways of life. Those forms of life determine the metaphysics the language necessitates. (For instance, the view that “the self is a substance that is identical over time and is that which acts and is the agent of moral responsibility” is ‘required’ by law and adopted in its ontology. )
For Nietzsche ‘things’ do not exist independent of perspectives; objects—the members of an ontology—exist within theories; they do not have character independent of them. Our concepts carve up the world according to our interests; they give us a lens through which we may categorize and make comprehensible the world. Our interests dominate our theoretical presumptions; we assess explanations by their consonance with those interests and our values.
 Resonances with the pragmatist theory of truth may also be found in In Truth and Lies in a Nonmoral Sense.
 (Danto, 86)
 (Danto, 60-61)