In this chapter, Krifka proposes a mereotopological formal semantic theory, enriched with a temporal dimension (a spatiotemporal haptomereology) that can account for the individuation of objects and (portions of) substances over time in terms of an ontology that underlies our use of natural language in the sense of Bach’s (1981) natural language metaphysics. Krifka’s spatiotemporal haptomereology can model not only how entities in space are connected but also how entities in time are connected. This, in turn, allows for the definition of solids, liquids, gases, grains, and individuals. For example, a solid in an interval t, t’ is an entity whose interior parts touch the same parts between t and t′. With these theoretical developments, Krifka proposes an account of different types of individuation over time. For example, he proposes that material identity over time can be established via matter individuals: individuals that are understood as identifying the same matter over time. The re-identification of matter over time, it is proposed, is based on the mereotopological notion of maximally self-connected entities described by Grimm, and a haptomereological modeling of change over time.