Abstract

I present a new theory of the composition of material objects. An important component of it is the claim that objects have non-concrete objects as parts. A non-concrete object is an object that lacks many of the features that concrete objects typically have—size, shape, mass, location, causal abilities, etc.—but yet is unlike typical abstract objects since a non-concrete object could have those features. This is an ontology defended by Timothy Williamson, but I employ it in a new manner to solve problems in the metaphysics of material objects. Specifically, I think it allows us to improve upon the Worm Theory, which claims that objects persist through time by having temporal parts. One main argument for Worm Theory is that it can preserve the principle that no two objects can share all the same proper parts. This is a principle that I think is intuitively gripping, but that I also argue for. Worm Theory therefore is to be preferred to the more ‘commonsensical’ Endurantist view on which objects are ‘wholly present’ at each moment at which they exist; the reason being that Endurantism gives the result that objects—like a statue and the clay it’s made out of—share all the same proper parts. By instead claiming that such objects also have temporal parts, Worm Theory manages to avoid this bad result for particular cases. The problem, however, is that it can’t avoid that result for all cases. We can easily imagine cases in which a statue and the clay from which it is made come into and out of existence at the exact same times. Thus the objects would not differ even with respect to their temporal parts. The view that I advance instead claims that objects must have something like modal parts. Thus we could say that since there is a possible world in which the clay exists without the statue, they do not completely overlap with respect to their modal parts. And so we avoid the bad result for all cases. The problem, however, is that there are no such things as objects that don’t actually exist. Hence, there couldn’t be such modal parts. Nonetheless, we can get something like modal parts by holding that such things actually exist, but are simply not actually concrete. Thus, the ‘pieces of clay in other worlds’ do actually exist, but they are not actually pieces of clay. They are non-concrete objects that could be pieces of clay. So even in a case where the clay and statue are created and destroyed at the same times, they differ with respect to their non-concrete parts. I call this the LED Theory because objects resemble LED display boards: just as the board is composed of numerous lights, each of which can be on or off, so objects are composed of numerous parts, each of which can be concrete or non-concrete. The paper provides further defense of this view and response to objections.