ABSTRACT
The account just given of public time depends on a distinction between the instants that mark the beginning and end of isochronous intervals and the intervals that lie between these instants. The distinction between instants and intervals is one that is difficult to draw clearly. It is dangerously easy to suppose that instants must be extremely short intervals, and that intervals must be composed of a large number of instants. Ideally, instants are like points; they have no extension or magnitude. An instant corresponds to a real number; a temporal interval corresponds to an interval of real numbers. This chapter discusses the St Augustine's argument of the ever-shrinking present, as the one to which the distinction between instants and intervals is most immediately relevant. Denseness established, Dedekind's argument will be deployed to give a formal proof that we need to ascribe to public time, as well as to private time.
