 One might complain that the version of the tolerance principle cited above is too lenient. Perhaps it is not true that the bicycle could have come into existence with just two thirds of its original components: perhaps a threshold of, say, 90% or more is required. However, the simple argument given above can be adapted to generate a contradiction between the restriction principle and any tolerance principle that permits some difference in the bicycle’s original composition, simply by introducing a longer chain of possible worlds. Thus the transitivity argument appears to force the proponent of transworld identity to choose between two implausible claims: that an object such as a bicycle has all of its original parts essentially (thus denying any version of the tolerance principle) and that an object such as a bicycle could have come into existence with few (if any) of its original parts (thus denying any (non-trivial) version of the restriction principle). Moreover, it is clear that the problem can be generalized to any object to which versions of the tolerance principle and the restriction principle concerning its original material composition have application, which appears to include all artefacts, if not biological organisms.