Thought experiment: The ship of Theseus

The origins of this thought experiment are not completely clear, but according to Marc Cohen (2004), it was first expressed in writing by Plutarch in the Vita Thesei.

There exists a ship owned by Theseus, who was a brave warrior. Theseus’ ship was decided to be kept and maintained by the Greeks as a memorial of his life. However, over time the parts of the ship would decay and would require replacement. After a long time, every single part of the original ship of Theseus had been replaced by new parts.

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The question we need to answer is: Is this is ship still the ship of Theseus?

If you answer yes, why? If no, when did it cease to be Theseus’ ship?

After you consider your answer to the first thought experiment, consider this next thought experiment, which comes from Richard Swinburne (2010):

Imagine I die due to a brain haemorrhage that is incurable today. My body is cryogenically frozen until a cure is discovered. During my time being frozen, an earthquake at the facility results in parts of my brain being broken apart, with some parts of my brain being lost forever. In the future, I am unfrozen, cured, and had all missing parts replaced and broken parts mended. When I wake up, I behave just as I did when I was previously alive.

The question Swinburne asks us is: have I come back to life again?

After considering your answer, think about whether these two thought experiments are comparable. Or are there too many relevant differences?

Published by

Andrew Tulloch

I have a Bachelor of Arts majoring in Philosophy and Sociology, with a Political Science minor. I also have an honours degree in Philosophy. I am currently studying for my PhD in Philosophy.

4 thoughts on “Thought experiment: The ship of Theseus”

  1. Is the ship still the ship of Theseus? Ha ha! I am inclined to say neither yes or no, if you consider the notion that nothing really ‘is’ or ‘is not’. Things are constantly coming in and out of existence. That is to say that depending on the conditions that arise, a variety of things may potentially come into existence, whereas if the prior conditions do not come into play, then neither can the resulting outcomes. No body of water, no need for a ship to sail in so to speak. Therefore every artifact of man is temporary in motion, as long as the ecosystem supports it. If you happen to be living in a time when a piece of technology is in operation, then you could say that it exists for pragmatic purposes but if you live in a time when it doesn’t, you better brace yourself for attack if you say something exists but other minds are too shallow to detect it.

    Another option is to pick yes. For all intents and purposes the Ship of Theseus remains the same. How so? It’s unlikely that the government will expect you to register it as a new ship if you gradually repair it top to bottom.

    On that note, what about the Parliament of Australia? Would the Senate or the House of Representatives cease to exist just because all the former members have passed away? Of course not. Even if you tear down the physical premises, its function or ideal remains the same, even if the elected members meet up in a church basement.

    Another option is no. Imagine yourself as an aboriginal person who belongs to a tribe that does not believe in private property. The notion of a ship belonging to Theseus, or any other man for that matter, would seem absurd. It may also be difficult to understand the concept of a ship if no one in the tribe ever heard of it.

    As for the Swinburne experiment we could go either way or into multiple directions. The fact that the body regenerates all its cells several times throughout a life time and yet we remain the same person, supports the notion that we would remain the same person once unthawed in the future.

    On the other hand we could say that we are not the same person because there are foreign parts added to us. The fact that people take on personality traits of an organ donor lends support to this. In other words there are cases that suggest that if you receive someone else’s liver, then you may take on new behavioural tendencies that were not present before you received that organ. So in this sense, as well as in other senses, we could say that we would not be the same person once brought back to life in the future.

    In another sense we could no longer be the same person if we remove all former conditions from our environment. The fact that Andrew is in the process of attaining an academic discipline and is also a father, largely shapes his personality and character, therefore without these relationships, the Andrew that is would no longer be the same man.

    Furthermore, both experiments in question could also be compared and contrasted until the cows come home and give birth to horses. In other words dichotomy has no end and yet it is very useful in regards to extending our thought. So we could say that they are comparable in that they demonstrate that there is no permanency to anything in life, including human consciousness, or we could say the experiments differ in that one deals with the complexity of being human and the other with becoming a thing, and therefore they can’t be adequately compared.

    All in all what each individual may find in this exploration is some kind of mirror reflecting back their own bias and limitations. In other words there is no escaping duality but we can use it to avoid the extremes. That is we can learn to lessen the confusion and suffering of ignorance if we avoid going down dead end pathways. Once we get too fixated on a particular position, it somehow comes back and kicks us in our arses. Like some of the ancient philosophers, perhaps it is wiser to neither affirm nor deny anything, unless of course it is one’s desire to go back into the cave to get shackled.

    Liked by 1 person

    1. Thanks Jason,

      Yes I find this thought experiment interesting as, unlike many thought experiments, its aim is to put forward an answer that is far from obvious. As I think you raise in your well thought out comment, a major issue can be the socially constructed nature of concepts. And identity is no exception. There is a philosophical discipline that you may be interested in regarding your neither affirming or denying comment, which is Pyrrhonean skepticism. Pyrrhonean skeptics apply such skepticism to philosophical problems. My honors thesis was on a method by Walter Sinnott-Armstrong called Contrastivism. He responds to philosophical problems by putting them into contrast classes, but takes a Pyrrhonean skeptic position on which one is ‘really relevant’.

      Liked by 1 person

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