The Ship of Theseus is a quite old thought exercise. At that time, science and philosophy were not as separated as today. Actually, after reading the nice comic

The Ship of Theseus is a quite old thought exercise. At that time, science and philosophy were not as separated as today. Actually, after reading the nice comic book Logicomix [0], I learned that the philosophical thought exercise of Wittgenstein, Russel and others, on trying to rationalize the world at the beginning of the 20th century, is actually what lead to a fundamental axiomatic redefinition of mathematics themselves. So it seems far stretch to call philosophical thought experiment not scientific. I agree that it is not scientific in the modern sense, after Karl Popper introduced the concept of falsifiability in 1935 [1], shortly after Hilbert advocated for rigorous proofs in mathematics in 1917 [2]. Although at that point, it is mostly a matter of vocabulary, thought experiments seem necessary for the advance of science. [0]: https://en.wikipedia.org/wiki/Logicomix https://en.wikipedia.org/wiki/Logicomix [1]: https://en.wikipedia.org/wiki/Bold_hypothesis https://en.wikipedia.org/wiki/Bold_hypothesis [2]: https://en.wikipedia.org/wiki/Hilbert%27s_program https://en.wikipedia.org/wiki/Hilbert%27s_program