In general, contemporary metaphysics is deeply sceptical of the familiar objects in which common sense believes. It is far more ready to attribute reality to entities that are much smaller – to the particles and wave packets and strings which microphysics treats as real, or to the “mereological simples” for which philosophical reflection provides some support. Any such view must find some way of explaining why there appear to be familiar medium-sized objects in the world. Many metaphysicians suppose that we can do just that. We can explain why it appears that the microparticles of the world compose familiar objects, why it appears that these objects persist across careers in which they lose and gain component microparticles, and why it appears that these objects have and exercise causal powers. The main business of this book is to argue that leading examples of such reductive explanations fail. For time and again such explanations project downwards, onto the small entities of the preferred ontology, structures and relations and features that properly belong to familiar objects. Such projection is harmless so long as one allows that there also are, in addition to the small entities, the familiar objects that form the starting point of the projection. But if – as is generally the case – the aim is to expunge familiar objects from ontology, the invocation of such structures and relations and features is illegitimate.