The Ship of Theseus as an Example of the No-Persistence Theory

I choose to defend the Temporal Part Theory instead of the other two theories, but before we go into further detail about why I chose to defend this theory, we must know what Persistence is through time and Qualitative change. Persistence through time is when an event seems to exist in more than one place throughout time. For e.g., a runner is running (which is the event) at time t1, and the same runner is still running at time t2.

So the runner persists through time. As for Qualitative Change, you have the same event persisting through time, but that event undergoes some changes, but we have to make sure that the changes are applied to the accidental properties of an event rather than the essential properties, for e.g., the same runner was running at time t1 but at time t2 he was taking a rest.

Amongst the three theories we have studied so far pertaining to Persistence and qualitative change, I will go ahead and support Temporal Parts Theory, also known as Perdurantism. We will start off with are temporal parts. Temporal Parts is that at any point in time, you are not the whole self, but instead, you are just a part of yourself. The temporal part takes time as another dimension, like space, and claims that individuals have temporal parts as well as spatial ones. For perdurantists, nothing is wholly present, but rather “objects are four-dimensional”1. The only problem that perdurantists face is the fact that, for perdurantists, an object might not change over time. For e.g., a person who has short hair at time t1, another part of an individual has long hair at time t2. This position might seem counterintuitive, but it may seem to solve many problems of identity over time.

Now we talk about our very first opposition, the Standard View, or some would call it the Endurantist. In this case, objects do not have temporal parts like the Perdurantists, but instead, one is wholly persisting through time; for this very reason, you do experience change because you, as a person, notice hair growth. But explaining the idea of change gets a bit trickier over here. For e.g., if we consider a group of people who are going through an experiment, all of them got their hair to grow for the experiment over a period of four months; now, after the span of four months, all of them have long hair. How can all of them have long hair at the same time and have short hair a few months back? That seems to break the law of contradiction, which states that “x cannot be both P and Not-P”2.

The Endurantist might try to come up with a solution by reverting to Prior’s theory of Presentism, which claims that only the present exists. But you might again face problems with this theory because not everything exists in the present.

The Endurantist will not give up and come back with another solution which is time. For e.g., all the people in the experiment took more time than others to get that certain length of hair growth, while some took less. So “time-indexing”3 seems to solve the problem, but some philosophers fail to comply with this solution because it is just made up, or a better word to describe it would be “ad hoc”4.

It doesn’t end over here; this theory faces yet another problem which we discussed earlier in our first paper, that is the multiple location problem for universals which states that “if a universal is in each thing that instantiates it, the property will be (wholly) in more than one place simultaneously.”5 In our case, for Standard View, it would be incorrect to say that an “individual or an object can exist in its entirety at more than one time”6, because how can one thing exist in its entireness in more than one place.

Last, of all, we come across the last No-Persistence theory by Arnauld and Nicole. Which simply says that nothing can ever persist at all, even if it undergoes a qualitative change. All that change does, is that it involves a new object. Taking our very simple example of an individual who grows his hair. At time t1, that individual had short hair, but after some time at t2, he had long hair. According to the no-persistence theory, that individual is not one but two individuals. This is simply an absurd theory and, as my professor would say, “ontologically annoying.”7

The best explanation of this theory would be the Ship of Theseus, which is that the ship had all its planks replaced and was completely a different ship compared to what it was 1000 years ago with all its ancient planks. Those old planks were then used to build a complete replica of the old ship. So now you have two ships, one which has the new planks installed and one with the original 1000-year-old planks on it. This example is similar to the BODY WORLDS exhibition, where you see dissected human bodies and other anatomical structures of the body that have been preserved through the process of plastination. According to my perspective, this is Persistence over time because the ship was destined or determined (Theory of Determinism) to go through this process in the future, which is the present right now, and that is why we still call the Ship of Theseus, the Ship of Theseus and not something else and “that is what prevents the mind from the perceiving the distinction of these subjects”8. Suppose you ever get the chance to visit the BODY WORLDS exhibition. In that case, you will notice that the names of the people who are still mentioned, whose bodies were donated for plastination, are displayed in that exhibition.

To sum this up, in the paragraphs above, we discussed the temporal parts theory over the other two theories because we consider the subject as different parts when it goes through different stages at times t1, t2, and t3, respectively. But those stages or time slices belong to the same thing. The only objection we faced was that this theory doesn’t explain change properly. Per the Standard View, the subject exists fully at each moment. We could say for this theory that we experience qualitative change, unlike Temporal Part theory, but it had some problems, and that is why Standard View wasn’t our choice as it had problems like the multiple location problem for universals; the logic problems that we discussed above and etc. instead of only one problem of change which we faced in the Temporal Part Theory. Finally, the No-persistence theory explicitly mentions that the subject that entails a qualitative change, that subject is no longer the same subject and is now a new subject after the change. That is the only reason I chose not to support No-Persistence Theory.

Did you like this example?

298

12