Views from the Abyss #55: The Ship of Theseus

Q. I was watching some classic British comedy, and it got me thinking. If I had a broom, and I replaced the head 17 times and the shaft 14 times, would it still be the same broom?

A. Yes.

Q. Really? It's that simple?

A. Yes, it really is that simple.

Q. But... None of the constituent parts of the original broom are part of it anymore. How can it still be the same broom?

A. When you attempt to apply objective standards to conceptual reality, you will often come across these pseudo-paradoxes. Put simply, a 'broom' is a conceptual identity, and is considerably more than the sum of its physical parts.

If we were to approach the question objectively, we could say that if so much as a single atom had changed, it would no longer be the same. However, it would also not be a 'broom'. It would be a bunch of atoms floating about in the ether, together with all the other atoms in the entirety of the universe. In fact, even that description is partially conceptual—the reality is much more depressing.

Objective reality is not meaningful to us, and that is why we apply our own meanings. A 'broom' cannot exist objectively—it can only exist as an application of conceptual identity, and that means it comes as part of a package: it has a name, a form, a history, a function, an assignment of ownership, and sometimes even sentimental value.

Changing any individual facet does not affect its conceptual whole, providing too many changes are not made simultaneously. So for example:

• Calling it a '箒' instead of a broom
• Never using it for its intended purpose
• Giving the broom to somebody else (changing its ownership)
• Swapping out a physical constituent part with another part that is conceptually equivalent

Every time an individual facet is changed, the identity of the broom adapts to accommodate the change. It does not become a different broom, because the bulk of its identity remains unchanged from the previous instance. As such, it can claim to maintain continuity over time.

* Now, if you were to take the original discarded shaft and the original discarded head and reassembled them, then that would be a new broom (of presumably limited value). I don't make the rules...

This is of course a rationalisation of an emotionally based claim. It doesn't matter though: objective criteria do not apply, because conceptual reality is whatever we collectively agree that it is.