 Options (i) and (ii) seem intolerably arbitrary, since the mended ship and reconstructed ship seem to have equal claim to being Theseus II. Option (iii) is out as well. If Theseus II is identical to both ships, then (by the transitivity of identity) they must be identical to one another; but they cannot be identical because they have different properties (e.g., the one but not the other is composed of the original planks). Option (iv) is problematic as well. The history of maintenance by itself would have sufficed for the persistence of Theseus II; the preservation and reassembly of the original parts by itself would likewise have sufficed for the persistence of Theseus II; and here we have managed to secure both. As Parfit (1971: 5) would say, “How could a double success be a failure?” Thus, we get (v) from argument by elimination.  Fitting.[30]