 How could insisting on the relativity of the answer to an identity question to a kind help with the diachronic identity puzzle posed by Cup and Tcup? Here is one way that it could. Suppose that nothing is a cup when it is a proper part of a cup. Then Tcup fails to qualify as a cup at t when it is a proper part of Cup. In that case a relative identity theorist can say the following. At the later time t′ Cup is the same cup as Tcup. Since Tcup is not a cup at the earlier time t, neither Cup not Tcup at t′ is the same cup as Tcup at t. Moreover, for any kind K, Cup is not the same K as Tcup at t. Identifying Cup with Tcup as the same cup at t′ places us under no constraint to identify Cup with one of its proper parts, Tcup, at t.