# Transcript - Light board

Hi my name is Ryan and this is a light board example, for my example I'm gonna be talking about the Ship of Theseus, this is also known as Theseus Paradox but it's actually more of a thought experiment than a paradox.

It was developed by an ancient Greek philosopher called Plutarch and the basic formulation of it is this. If you have a ship made up of exactly 100 pieces of wood, that's my plank of wood and then you remove a piece of wood let's say every week. You replace that piece of wood with a brand new piece of wood so you bring along a new piece of wood and then all you're doing is replacing one of those each week so that what's happening is after 100 weeks no piece of wood on the ship is the same as what was originally there.

So the ship of Theseus is now made up entirely of new wood the question is then is that the same ship, is it still the ship Theseus keeping in mind we replaced it one piece at a time. So after week one we have only one piece of wood on that ship that's been replaced, and I think it's fair to say it's still the ship Theseus we've just replaced one plank but following that logic we keep going we keep replacing pieces of wood until there is none of the old pieces left and we end up with this second ship. Is it still the ship Theseus I mean we were using it the same way, traveling back and forth over all those weeks and we've replaced it gradually one at a time. Is it still the same ship, that's a question I'm not gonna answer for you it still hasn't been properly answered but it takes another turn here so whether or not you think that that is still the same ship as the earlier one.

Thomas Hobs another famous philosopher later came up with a next step in this logic problem, he said what happens if we take these 100 pieces of wood here and actually reconstruct the ship the original ship, so we've still irreplaced those pieces we've pulled all off we've put them in a pile and we've ended up with the ship made whole of new wood and then we've taken all the old wood and we've made the ship again. So if back here as we were gradually replacing the pieces of wood you said nah no it's still the same ship we've just made it out of new wood. We've maintained it using new wood, then what happens when u build this one if you said this is the real ship ,what happens when you reconstruct all the old wood into the same ship they look exactly the same for all intensive purposes.

It's just that this is the original wood and that's new wood, are they both the ship Theseus, now this problem takes a final turn. If we consider that the human body, so this is a human body is made up of lots of little cells basic anatomy then hopefully if you've studied anatomy you might know that these cells get replaced on a regular basis, our cells die they regenerate so at some point in time every human being is no longer made up of the cells we were originally made of at birth.

So depending on what logic you could use for the ship Theseus problem thus far your question is then finally if you said that this ship is not the original ship that this ship we've ended up is no longer the ship Theseus and we consider that every cell in the human body gradually regenerates until no cell is the same are you the same person you were when you were born, that's it I hope you've enjoyed the example.

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