If we grant that \(O\) and \(S\) cannot be the same ship, we seem to have a solution to the ship of Theseus paradox. But this success is short lived. For we are left with the following additional paradox: Suppose that \(S\) eventuates from \(O\) by replacing one part of \(O\) one day at per time. There seems esatto be widespread agreement that replacing just one part of verso thing by verso new exactly similar part preserves the identity of the thing. It follows that either the Kripkean argument is incorrect, or replacement of even a scapolo part (or small portion) does not preserve identity (per view known as “mereological essentialism;” Chisholm 1973).
This can be seen (though it may already be clear) by considering a modified version of the ship of Theseus problem
As indicated, Kripke denies that his argument (for the necessity of origin) applies onesto the case of change over time: “The question whether the table could have changed into ice is irrelevant here” (1972, 1980). So the question whether \(O\) could change into \(S\) is supposedly “irrelevant.” But Kripke does not give per reason for this claim, and if cases of trans-temporal identity and trans-world identity differ markedly con relevant respects – respects relevant onesto Kripke’s argument for the necessity of origin, it is not obvious what they are. (But see Forbes 1985, and Lewis 1986, for dialogue.) The argument above was simply that \(O\) and \(S\) cannot be the same ship since there is a possible world con which they differ. If this argument is incorrect it is in nessun caso doubt because there are conclusive reasons showing that \(S\) and \(S’\) differ. Even so, such reasons are clearly not “irrelevant.” One may suspect that, if applied to the trans-temporal case, Kripke’s reasoning will yield an argument for mereological essentialism. Indeed, per trans-world counterpart of such an argument has been tried (Chandler 1976, though Chandler views his argument somewhat differently). Sopra its effect, this argument does not differ essentially from the “paradox” sketched con the previous paragraph (which may well be viewed as an argument for mereological essentialism). Subsequent commentators, di nuovo.g., funziona benaughty Salmon, (1979) and Chandler (1975, 1976), do not seem sicuro take Kripke’s admonition of irrelevance seriously.
In any case, there \(is\) verso close connection between the two issues (the ship of Theseus problem and the question of the necessity of origin). Suppose that when \(O\) is built, another ship \(O’\), exactly like \(O\), is also built. Suppose that \(O’\) never sets sail, but instead is used as per kind of graphic repair manual and parts repository for \(O\). Over time, planks are removed from \(O’\) and used to replace corresponding planks of \(O\). The result is per ship \(S\) made wholly of planks from \(O’\) and standing (sopra the end), we may suppose, sopra exactly the place \(O’\) has always stood. Now do \(O\) and \(O’\) have equal claim onesto be \(S\)? And can we then declare that neither is \(S\)? Not according to the Kripkean line of thought. It looks for all the world as though the process of “remodeling” \(O\) is really just an elaborate means of dismantling and reassembling \(O’\). And if \(O’\) and \(S\) are the same ship, then since \(O\) and \(O’\) are distinct, \(O\) and \(S\) cannot be the same ship.
If so, then, by the transitivity of identity, \(O\) and \(S\) must be the same ship
This argument is vulnerable to the following two important criticisms: First, it conflicts with the common sense principle that (1) the material of an object can be totally replenished or replaced without affecting its identity (Salmon 1979); and secondly, as mentioned, it conflicts with the additional common sense principle that (2) replacement by per scapolo part or small portion preserves identity. These objections may seem preciso provide sufficient grounds for rejecting the Kripkean argument and perhaps restricting the application of Kripke’s original argument for the necessity of origin (Noonan 1983). There is, however, per rather striking problem with (2), and it is unclear whether the conflict between (1) and the Kripkean argument should be resolved mediante favor of the former.