In this blog post, we will consider whether the nature of things can be maintained even as they change through the “Ship of Theseus” paradox.
Among the heroes of Greek and Roman mythology is Theseus, who defeated the famous Minotaur. There is a ship that Theseus rode to defeat the Minotaur, and people decided to preserve the ship to honor his achievement. The ship was later called “Theseus’s Ship.” However, as time passed, the ship gradually became worn out, and the worn-out parts were replaced with new planks. As a result, the ship was left without a single original plank. So, can we still call this ship the “Teseus’s Ship”? This debate is called the Teseus’s Ship Paradox. This debate raises the question of whether the judgment of an object can change depending on the changes in the object. There are many similar debates in the world, and the judgment of these debates varies depending on the case. What defines an object is its meaning. If there has been a change in the meaning to the extent that it is damaged, the object becomes something else, and if it still retains its original meaning, the object can be considered as the same object.
Let’s think about this problem in more depth using the example of a bicycle. What is the meaning of a bicycle? A bicycle is a vehicle that a person rides and moves by turning the wheels with the power of their legs. Suppose we change the frame of the bicycle, replace the saddle, and change various parts. At this point, although the bicycle itself has undergone many changes, it can still be called a bicycle as long as the meaning of a vehicle that uses two legs to turn the wheels via pedals is not compromised. However, if a motor is attached to the bicycle, it is no longer a bicycle because there is no need to turn the wheels with the legs, and it becomes a motorcycle or a two-wheeled vehicle. This situation is more pronounced when the meaning of an object is strongly symbolic.
Let’s take the Blue House in South Korea as an example. The word “Blue House” itself means a building made of blue tiles. However, the Blue House has a symbolic meaning as the official residence of the President of South Korea. Therefore, even if the Blue House changes its appearance through construction, it will still be called the “Blue House” and will retain its meaning as the official residence of the President.
The definition of things as meaning is not limited to objects. It can also be applied to people. For example, let’s say there is a person named Friend A. If A loses his leg in an accident and has to wear a prosthetic leg, A will have changed, but the meaning of him being a close friend will not change. Meaning is a subjective thing that is applied differently to different people, so different judgments are often made. If the meaning of being a friend includes external factors, and a person with a prosthetic leg is no longer in that meaning, then A may no longer consider him or her a friend.
Let’s consider a slightly different situation. B and C are friends. To B, a friend is someone who is close to him, has shared memories with him, and has a similar personality. If C has an artificial brain, and if that artificial brain preserves all of his previous memories and if his personality remains the same, then C will still be a friend to B. This is because it fits the meaning of C being a friend of B. On the other hand, if C, who has an artificial brain, is no longer considered a person and cannot be accepted as a friend, it is because the meaning of friend includes the condition of “person.” However, if the meaning of friend for B does not include the condition of “person,” C will still be B’s friend regardless of whether C is a person or not.
It may seem strange that the meaning of a friend does not include the condition of “being a person,” but think back to when you were a child. We considered robots and dolls we played with to be our friends. They could not speak, were not human, and were not living things, but we considered them to be our friends. We may no longer consider them to be our friends now. This is simply because the meaning of what defines a friend has changed as we have grown up. The same goes for pets like dogs and cats. They are not people, but they can become friends with some people. The reason for this is that the meaning we give to something determines how we judge it.
The meaning I give to the “Teseus’ Ship” right now is to remind people of the fact that “Teseus defeated the Minotaur on this ship” and to honor his achievement. Therefore, I do not think that the ship’s planks have changed and it is no longer the “Teseus Ship.” That is why I think it is important to maintain the ship. If you make a model of the “Teseus Ship,” it will only be a “Teseus Ship model,” and it will not be the “Teseus Ship.”
Also, the person with the artificial brain I mentioned above is still the person I know. For me, what defines my relationship with that person is his way of thinking and the events we share. As long as these things don’t change, that person will still be seen as the same person. But this is just my current opinion, and if my definition changes, my judgment may also change.
Every object, including things and people, has its own way of being defined by each person. That definition may vary depending on the time and place. However, the meaning always exists at any given point in time, so judgment at that point can be made sufficiently. Even the thoughts of each individual can change from time to time, and the thoughts of many people cannot be the same. And since standards are also different for each person, even if the perspectives are slightly different, they can reach different conclusions. This is why there may be endless debates like the “Teseus’s Ship” paradox.
