Time passes, and the inexorability of its passing has deep emotional significance. One of the main themes of this thesis involves an investigation into the metaphysical nature of the passage of time. What sort of metaphysical account of passage should be given? And do our emotional responses to temporal passage have metaphysical implications? The other main theme of the thesis is the issue of the metaphysics of persistence. When a thing is present at more than one time, what is the (...) metaphysical underpinning of its persistence? Some subsidiary issues, which are nevertheless important in their own right, are also discussed. There are interesting connections between the issues of persistence and these further issues, which include the nature of vagueness, and the distinction between intrinsic and extrinsic properties. (shrink)