 As noted above, Lewis’s account fails to provide an account of the standard notion of intrinsicality (which is identity interiority), and at best provides an analysis of duplication preservation. Marshall has recently provided an account in terms of perfect naturalness that, if successful, instead provides an analysis of identity interiority. If Marshall’s account works, then it can also be modified to provide successful analyses of the other notions of intrinsicality described in section  2.4.