In this paper, I provide an argument for the assumption that contents supervene on vehicles, which is based on the explanatory role of representations in the cognitive sciences. I then show that the supervenience thesis together with the explanatory role imply that the individuation criteria for contents and vehicles are tightly bound together, such that content internalism (externalism) is in effect equivalent to vehicle internalism (externalism). In the remainder of the paper, I argue that some of the different positions in the debate stem from different research questions, namely the question about the acquisition conditions and the question about the entertaining conditions for mental representation. Finally, I argue that the thesis of externalism is much more interesting if understood as a claim about how mental representation works in our world as opposed to how they work in all metaphysically possible worlds. In particular, I argue that this ?nomological? understanding of the thesis is able to explain how and why the experimental methods used in contemporary cognitive sciences are able to provide insight into behavior generation.