Abstract: This book concerns the nature of time. It shows how presentism, the view that only the present exists, can be defended. Part I of the book shows how presentism is the only viable alternative to the tenseless theory of time. It then develops a framework for solving problems traditionally associated with the position, such as finding truthmakers for past-tensed statements; McTaggart's argument; the need for other times other than the present time; how to give the proper semantics for future contingent statements; how to deal with transtemporal relations between the past and the present; how we can meaningfully talk about past individuals; and how accounts of causation relations can be formulated. Part I concludes with a discussion of the direction of time and causation, the decision-theoretic problem known as ‘Newcomb's problem’, and the possibility of time travel and causal loops. Part II focuses on the problems for presentism raised by relativity theory. It begins by giving a self-contained exposition of the concepts of special relativity and its philosophical implications. The last two chapters focus on certain cosmological models of general relativity: namely, the expanding universes, and Gödel's infamous model. The necessary physics is explained, with the aid of diagrams.

Keywords: time, presentism, truthmakers, McTaggart, future contingents, transtemporal relations, causation, Newcomb's problem, relativity, expanding universe, Gödel