Abstract

Commonsense metaphysics populates the world with an enormous variety of macroscopic objects, conceived as being capable of persisting through time and undergoing various changes in their properties and relations to one another. Many of these objects fall under J. L. Austin’s memorable description, “moderate-sized specimens of dry goods.” More broadly, they include, for instance, all of those old favourites of philosophers too idle to think of more interesting examples—tables, books, rocks, apples, cats, and statues. Some of them are natural objects, such as rocks, apples, and cats. Some are artefacts, such as tables, books, and statues. Some are living things, such as apples and cats. Some are inanimate things, such as tables, books, rocks, and statues. To such a list we could add much larger natural objects, such as planets and stars, as well as much smaller ones barely visible to the naked eye, such as mites and pollen grains. Telescopes and microscopes enable us to extend the scale further in both directions, to include such things as galaxies and microbes. To call into question the existence of all or any of these things would appear to be an extravagance of the sort that only a philosopher could indulge. Until fairly recently in the history of philosophy, however, the only way in which their existence would have been called into question was in the context of the debate between realism and idealism. Idealism calls their existence into question by questioning the existence of an “external world” as such, proposing instead that only minds and their experiences exist. What is much more recent is the suggestion that, although there is an external world of entities existing in space and time, it is not in fact populated by most, or perhaps even by any, of the objects recognized by common sense. Instead, it is suggested, the world is populated by submicroscopic entities of a highly esoteric kind best understood by theoretical physicists—entities which may not even qualify as “objects” in anything like the familiar sense because, quite possibly, they should not be thought of as having precise spatiotemporal locations or as persisting over time and through processes of qualitative change. Let us call these putative entities ‘atoms’, without prejudice as to whether they conform to the descriptions currently favoured by physicists in speaking of what they call ‘atoms’. In other words, let us use ‘atom’ as a place-holder for whatever kind or kinds of entities an ideal or completed physics would postulate as the “ultimate” constituents, as opposed to infinitely descending levels of ever more fine-grained physical structure, but let us set aside dispute over these alternatives for the time being, if only because we have little idea as to how to settle it.