 It should be mentioned, however, that David Lewis has argued that the reconciliation of identity through change over time with Leibniz’s Law suggested above is oversimplified, and gives rise to a ‘problem of temporary intrinsics’ that can be solved only by treating a persisting thing that changes over time as composed of temporal parts that do not change their intrinsic properties. (See Lewis 1986, 202–204, and for discussion and further references, Hawley 2001; Sider 2001; Lowe 2002; Haslanger 2003.) In addition, it is partly because Lewis regards the analogous account of transworld identity in terms of modal parts as an unacceptable solution to an analogous ‘problem of accidental intrinsics’ that Lewis rejects transworld identity in favour of counterpart theory (Lewis 1986, 199–220; cf. Section 1.2 above).