Book excerpt: Thinking about space is thinking about spatial things. The table is on the carpet; hence the carpet is under the table. The vase is in the box; hence the box is not in the vase. But what does it mean for an object to be somewhere? How are objects tied to the space they occupy? In this book Roberto Casati and Achille C. Varzi address some of the fundamental issues in the philosophy of spatial representation. Their starting point is an analysis of the interplay betwen mereology (the study of part/whole relations), topology (the study of spatial continuity and comapctness) and the theory of spatial location proper. This leads to a unified framework for spatial representation understood quite broadly as a theory of the representation of spatial entities. The framework is then tested against some classical metaphysical questions such as: Are parts essential to their whole? Is spatial co-location a sufficient criterion of identity? What (if anything) distinguishes material objects from events and other spatial entities? The concluding chapters deal with applications to topics as diverse as the logical analysis of movement and the semantics of maps.