 According to conceptual pluralists, there can no more be an answer to the question “What is the structure of the world?” outside of some scheme for classifying entities than there can be an answer to the question of whether two events \(A\) and \(B\) are simultaneous outside of some inertial frame for dating those events. The objects that exist are the objects some conceptual scheme says exists—‘mesons exist’ really means ‘mesons exist relative to the conceptual scheme of current physics’.