Realization, Completers, and Ceteris Paribus Laws in Psychology

I defend Jerry Fodor’s ([1991]) account of the semantics of ceteris paribus laws against an objection raised by Peter Mott ([1992]). In doing so, I clarify certain issues regarding the nature of realization. I argue that not all things that realize a state or property are realizers of that state or property: the relation x realizes y tolerates the inclusion of gratuitous elements in x—elements that play no particular role in the realization of y—whereas the relation x is a realizer of y does not. I then criticize a rejoinder that, in effect, builds such gratuitous elements into the antecedents of the laws of a science of the realized properties.