Abstract

Recently, Judith Jarvis Thomson has offered a definition of the constitution relation against the backdrop of a robust ontology of objects she calls all‐fusions. Despite finding her reasons to believe in all manner of all‐fusions intriguing, in this paper I note an unsatisfactory consequence of her position for constitution‐theorists. I argue that an unrestricted commitmentto all‐fusions should lead the constitution‐theorist to reject her definitionof the constitution relation, on the grounds that by choosing our all‐fusionscarefully, we can secure the unpalatable result that two different all‐fusionsconstitute (or are constituted by) the same thing, even though neither one ofthem constitutes the other.