 Before we plunge into arguments about whether temporal parts exist, it’s worth clarifying some terminology. First: perdurance theory is sometimes called ‘worm theory’, especially when it is contrasted with stage theory. This is because perduring objects stretch out through time just as (we all agree) earthworms stretch out through space. Worm theory has nothing to do with wormholes, and, sadly, people don’t usually describe themselves as ‘worm theorists’. Second: ‘four-dimensionalism’ is sometimes used as an umbrella term for perdurance theory and stage theory, and ‘three-dimensionalism’ as a name for endurance theory. This is because perduring objects (and sums of stages) are four-dimensional, whereas enduring objects are three-dimensional, wholly present at each moment. But some non-standard views of persistence, including ‘mixed’ views, do not fall neatly into either category. And beware: other authors use ‘four-dimensionalism’ and ‘three-dimensionalism’ as names for different theories of time, rather than different theories of things in time. Third: ‘continuant’ is sometimes used as a neutral term for any ordinary persisting thing. In this sense, we can ask whether continuants endure or perdure. But the label ‘continuant’ is more commonly reserved for enduring, three-dimensional objects. This marks a contrast with processes or events, and carries the implication that perdurantists foolishly identify material objects with events. So it tends only to be endurantists who use the term ‘continuant’.