Sunday, November 29, 2009

The Boat Paradox

Imagine you build a wooden boat. As time goes on, you find that part of the boat needs to be repaired, and you replace it with another piece of wood. This process continues until each of the original parts has been replaced by another. Now the question: is this the same boat? If not, at what point did it become a different boat?

This problem has significant implications for our view of the human mind. Each of the body's cells (and indeed, each physical part) is constantly replaced by new ones. Yet, it is surely the case that I am the same person today I was three months ago. Does this suggest an immaterial aspect of humanity?

4 comments:

  1. There are certain cells that are not replaceable, and the DNA of the cells in your body remains the same set of DNA from when you were an embryo...

    In regards to the boat, it is the same boat because you simply replaced the parts of the boat. You didn't construct and entirely different one.

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  2. "In regards to the boat, it is the same boat because you simply replaced the parts of the boat. You didn't construct and entirely different one."


    Right. All of the parts were replaced with new parts. But what makes it the same boat?

    Consider this: if all of those replaced parts were put back together, then we'd have another boat. But would we have the same boat? There'd be two boats, and yet you declared the boat with the new parts to be the original boat. Surely, they cannot both be the same boat and yet numerically distinct.

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    Replies
    1. and whose boat would the reconstructed boat be?

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