In other cases of empirically discovered property identities, such as heat and kinetic energy, there is a story that explains the co-referential convergence.

However, others contend that the appeal to type-type identity does not so obviously void the need for explanation (Levine 2001). Even if two descriptions or concepts in fact refer to one and the same property, one may still reasonably expect some explanation of that convergence, some account of how they pick out one and the same thing despite not initially or intuitively seeming to do so. In other cases of empirically discovered property identities, such as that of heat and kinetic energy, there