Bri Ehrler
Metaphysics
Feb 5 2014

The problem of change and identity can often be explained with the story of the ship of Theseus. In this story, a man named Theseus docked his ship and over time, he and the ship, grew old and weak. Over time, the ship started to fall apart and needed new parts until eventually all the original parts were replaced with new ones. This newly renovated ship is the first ship to consider. There is also a second ship that was reconstructed from all the original pieces of the old ship that had been set into a separate warehouse and put back together. We now have two ships: the renovated ship (created by replacing the old parts with new) and the reconstructed ship (created by reassembling the original pieces that had been removed). The question is: Which ship, the renovated or the reconstructed, is the original ship of Theseus? Whenever one makes an identity claim, such that two things are the same and share all the same properties, one usually uses two different descriptions to explain such phenomena. For example, "Mark Twain is Samuel Clemmons". Mark Twain is the author that most people know for writing The Adventure of Tom Sawyer, but this was his pen name, not his actual name; thus, making Mark Twain a descriptive name, but nevertheless having the same identity as Samuel Clemmons. Back to the ship of Theseus, the problem lies when trying to differentiate which ship is the original ship based on the principle of identity. Are the two ships the same as the original ship with only different descriptions? Is one the original ship while the other is not? Or, are both not the original ship? For this paper I will analyze the idea that the reconstructed ship is the original ship. According to Leibniz's Law: X is the same as Y if, and only if, X and Y have all the same properties and relations; thus, whatever is true of X is also true of Y, and vice-versa. If we apply this law to the ship of Theseus, it can be said that the reconstructed ship has the same properties as the original ship due to fact that every piece that makes up the reconstructed ship belonged to the original ship. One problem with this argument could be that when we remove each piece from the original ship, it still seems to be intuitively the same ship. It would seem radical to say that once we remove one screw from the ship, it is no longer the same ship. This idea leans toward mereological essentialism such that every part is essential to the whole. If we accept this claim, then we must accept that nothing ever changes, but rather they exist and don't exist and are in constant destruction. If we remove one screw from the original ship and replace it with the exact same screw with the exact same dimensions and color, then an argument could be said that it is still the same ship. But, if we remove, say, all the masts and boards and perhaps more, then it can be said that because of the removal of one or more essential part, that is a part that defines something as a whole, then it is no longer the same ship. For example, if I need to replace an original engine to a '56 Chevy, then most car enthusiasts will say that it is a good looking car, but not considered to be the original car since an essential part was replaced. In conclusion, the original ship was no longer the original ship once an essential part of the ship was replaced with a new part and later became the original ship again once all the original pieces were put back together, using Leibniz's Law of identity.