“…This becomes apparent especially in connection with qualitative reasoning about space and time: here mereology proves useful to account for certain basic relationships among things or events; but one needs topology to account, say, for the fact that two objects or events can be continuous with each other, or for the relation of something being inside, abutting, or surrounding something else. (My present concern will be with the mereotopology of spatial structures; I have explored eventive and other temporal structures in joint work with Fabio Pianesi [25,26,27]. )…”