 Lewis’s is the most developed version of possibilist realism based on possible worlds. As a result, discussion of possibilist realism almost always focuses exclusively on Lewis’s version. There are, however, other versions of possible-worlds-based possibilist realism, and one of them deserves a brief mention. Assume that the universe is spread out in three-dimensional space and persists through one-dimensional time. The non-Lewisian version of possibilist realism in question may then be called ‘modal–dimensionalism’. It says that in addition to the four physical (spatiotemporal) dimensions, the universe has modal dimensions. Possible worlds are points in modal space as defined by the modal axes just as physical spatiotemporal points are points in physical spacetime as defined by the four physical spatiotemporal axes, and possible objects “persist” through possible worlds. A version of modal–dimensionalism is what W. V. Quine argued against when he took himself to be arguing against a typical possibilist realism (Quine 1976), and it is arguably the view many possible-worlds theorists adumbrated, however vaguely and inchoately, as the representative possibilist realist theory before Lewis forcefully articulated his own version.