Let's say we have a wooden ship. We replace each plank on the ship, one by one, until none of the original planks are part of the ship. Is it the same ship now? If not, when did it stop being the same ship? Now we take all those extra planks and put them together in the exact same way they were before. Are either of these ships the same ship as before, and which one?
This was the sort of question which made me hate philosophy.
However, Zeno Ferox just gave me an idea to solve this paradox once and for all. Supposedly, you only need to bless a rosary once--further blessings do not increase its blessedness. And if you replace, say, 20% of the beads, you don't really need to bless it again, because the blessing is integral to the rosary itself. Aha, so we know that it's still the same rosary even when 20% is replaced!
So, here's the experiment:
- Bless a rosary.
- Replace one bead.
- Ask the priest whether it is still blessed.
- Repeat steps 2 and 3 until all beads are replaced.
- Use the original beads to make another rosary.
- Ask the priest if the rosary is blessed.
I wouldn't have thought Theseus's Paradox to be a scientific question, but clearly I was wrong.