Good questions raised.
I would say that the ships could not be identical, for the simple reason that they occupy different positions in space. That makes them similar. With a single object, there is identity when the difference produced is regarded as not substantial. If it is regarded as substantial, then there is continuity, but not identity. An object that seems identical in the short term may, when regarded in a longer time frame, be regarded as merely continuous, because change is gradual but substantial. In the event that there is a reconstruction, for example, an historic building burns but is replaced, it can only claim similarity. When there is no similarity, identity, or continuity, there is destruction.
In the case of human beings, the claim to identity rests primarily on the idea of experience belonging to one actor. In a sense, people change substantially over time, but in another sense, they remain the subjects of their accumulated history, which is why there may be unresolved issues from childhood still haunting persons of substantial age. |
