Mereological destruction and relativized parthood: a reply to costa and calosi

Metaphysicians of various stripes claim that a single object can have more than one exact location in space or time – e.g. endurantists claim that an object persists by being ‘all there’ at different moments in time. Antony Eagle has developed a formal theory of location which is prima facie consistent with multi-location, but Damiano Costa and Claudio Calosi argue that the theory is unattractive to multi-location theorists on other grounds. I examine their charge that Eagle’s theory won’t allow an endurantist to account for certain cases of mereological change. I argue that the charge sticks, but not for the reasons Costa and Calosi think. Along the way, I explore an issue which is underexplored in their paper, namely, how an endurantist might modify Eagle’s theory to incorporate a parthood relation which obtains, not absolutely, but only relative to times.