This article offers an exposition of McTaggart’s paradox and examines several influential interpretations of it. Its principal aim is to reconsider the argument of John Ellis McTaggart, the prominent early twentieth-century metaphysician, for the unreality of time as articulated through a fundamental opposition between two ideas: “absolute reality” and “tensed reality,” and to draw from this opposition a number of conclusions relevant to contemporary philosophical debates concerning the nature of time. To this end, it reconstructs, with close attention to McTaggart’s own formulation, the structure of his argument—an argument intended to demonstrate that time involves a contradiction and therefore cannot be real. It then analyzes and assesses several alternative interpretations of the paradox: Heather Dyke’s account of the contradiction of tense, Huw Price’s view regarding the tension between inclusivity and exclusivity, and, most notably, Michael Dummett’s interpretation. Dummett maintains that the success of McTaggart’s paradox depends upon the acceptance of a substantive philosophical presupposition, namely, that a complete description of reality is, in principle, possible. Finally, the article argues that understanding McTaggart’s paradox within this framework has significant implications for assessing the legitimacy of the philosophical dispute between the A-theory and the B-theory of time. In particular, appeals to naturalistic arguments—that is, those invoking physical theories—in support of the B-theory rely upon a specific philosophical presupposition concerning the possibility of an absolute description of reality and are therefore vulnerable to the charge of begging the question.