This chapter discusses the epistemological, and ultimately metaphysical constitution of modern Science and its universal truth claim, as pointed out by philosophers like Robin George Collingwood, Richard Rorty and Nicholas Maxwell. Since representational and foundationist epistemologies led into the cul-de-sac of relativism, pragmatic approaches of Willard van Orman Quine, William James, and Charles Sanders Peirce are explored as possible alternatives to the attempt of legitimating truth claims on epistemological grounds. In absence of any sustainable epistemological argument for scientific universalism, the final section of the chapter analyses its core metaphysical suppositions and how and where these suppositions entail mechanisms for systematically devaluing and/or excluding other ways of knowing, labelling them as “unscientific” “beliefs”.