 These issues concerning the nature of metaphysics are further connected with issues about the epistemic status of various metaphysical theories. Aristotle and most of the Medievals took it for granted that, at least in its most fundamental aspects, the ordinary person's picture of the world is “correct as far as it goes”. But many post-Medieval metaphysicians have refused to take this for granted. Some of them, in fact, have been willing to defend the thesis that the world is very different from, perhaps radically different from, the way people thought it was before they began to reason philosophically. For example, in response to the puzzles of coincidence considered in Section 3.3, some metaphysicians have maintained that there are no objects with proper parts. This entails that composite objects—tables, chairs, cats, and so on—do not exist, a somewhat startling view. And as we saw in Section 3.1, other metaphysicians have been happy to postulate the reality of concrete merely possible worlds if this posit makes for a simpler and more explanatorily powerful theory of modality. Perhaps this contemporary openness to “revisionary” metaphysics is simply a recovery of or a reversion to a pre-Aristotelian conception of a “permissible metaphysical conclusion”, a conception that is illustrated by Zeno's arguments against the reality of motion and Plato's Allegory of the Cave. But no matter how we classify it, the surprising nature of many contemporary metaphysical claims puts additional pressure on practioners to explain just what they are up to. They raise questions of the methodology of metaphysics.