In one of the most iconic scenes in British television comedy, Trigger, the butt of so many ‘Only Fools and Horses’ jokes, proudly reveals that he has used the same road sweeping brush for his entire career. “This old broom”, he says “ has had 17 new heads and 14 new handles”. We, the audience, are laughing at his apparent stupidity long before Sid points out “how the hell is it the same bloody broom then?”
But, on closer examination, Trigger is maybe not quite as daft as a brush (pardon the pun) after all.
When Roman writer Plutarch published his ‘Life of Theseus’, he described how the Athenians had maintained the ship of their famous king in the harbour as a museum piece. Every year, Plutarch tells us, rotten planks were replaced with new ones such that, over time, every part of the ship had been replaced. So, was it still Theseus’s ship? (Yes, according to Trigger and, indeed, the Athenians!) If not, at what point did it cease to be his ship? It was, said Plutarch, a philosophical problem that had divided thinkers for generations.
In my mind, a similar question arises in relation to the Cutty Sark which had to undergo major restoration work following a serious fire in 2007. How much of the original fabric of the ship would have to be replaced before it ceases to be the Cutty Sark or will it always be the Cutty Sark regardless of how much of it is replaced, like Trigger’s Broom?
While I have got you thinking, I will leave you with this thought experiment posed by the Philosophy Foundation : if every wooden piece of Theseus’s ship had gradually been replaced over time by a metal part, could it ever be said that the eventual 100% metal ship was still Theseus’s?
I’m not going to attempt to answer this myself – the Philosophy Foundation does a far better job of outlining the possible solutions than I ever could.