 In the first section we briefly looked at one argument, the so-called modal argument for the necessity of identities, for denying that there could be temporary identities. Some philosophers have responded to some of the diachronic identity puzzles by maintaining that there could be indeterminate identities. An argument with a similar structure to the modal argument has been deployed to rule out indeterminate identities. Give their implications for identity across time the modal argument and the argument against indeterminate identities are set out in more detail in the next section.