Ought a Four-Dimensionalist To Believe in Temporal Parts?

Abstract

I borrow the title of this paper, slightly amended, from Parsons’ recent ‘Must a Four-Dimensionalist Believe in Temporal Parts?’ Four-dimensionalism, as I use the term, is the view that persisting objects have four dimensions: they are four-dimensional ‘worms’ in space-time. This view is contrasted with three-dimensionalism, the view that persisting objects have three-dimensions and are wholly present at each moment at which they exist. The most common version of four-dimensionalism is perdurantism, according to which these four-dimensional objects are segmented into temporal parts — shorter lived objects that compose the four-dimensional whole in just the same way that the segments of real earth worms compose the whole worm.