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The Ship of Theseus is an ancient puzzle: if every plank of a ship is replaced, one by one, over the years, is it still the same ship? Philosophers use it to ask what makes anything stay itself over time.

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The story behind the card

The story comes from the Greek writer Plutarch, around AD 100. Theseus, the legendary king of Athens who killed the Minotaur on Crete, sailed home in a 30-oared ship, and the Athenians preserved it for centuries, until about 300 BC, replacing rotten timbers with new ones. Plutarch says philosophers already argued over whether it was still the same ship. In 1655 the English philosopher Thomas Hobbes added a twist: if someone kept the old planks and rebuilt them into a ship, which one would be the real Ship of Theseus? Everyday versions include 'grandfather's axe', with a new head and a new handle, and Trigger's broom in the British sitcom Only Fools and Horses. The question matters for restored ships and buildings, and for how we think about people who change over a lifetime.

Türkçe oku
Theseus'un Gemisi, Antik Yunan'dan kalma bir düşünce bulmacasıdır: Bir geminin bütün tahtaları yıllar içinde teker teker değiştirilirse, geriye kalan hâlâ aynı gemi midir? Filozoflar bu soruyla, bir şeyin zamanla değişse de nasıl “aynı şey” kalabildiğini tartışır.

Hikâye, MS 100 dolaylarında yazan Yunan yazar Plutarkhos'tan gelir. Girit'te Minotor'u öldüren efsanevi Atina kralı Theseus, yurduna otuz kürekli bir gemiyle dönmüştü. Atinalılar bu gemiyi yüzyıllar boyunca, MÖ 300 dolaylarına kadar, çürüyen tahtalarını yenileriyle değiştirerek korudu. Plutarkhos, filozofların daha o zaman bunun hâlâ aynı gemi olup olmadığını tartıştığını yazar. 1655'te İngiliz filozof Thomas Hobbes soruyu bir adım öteye taşıdı: Biri sökülen eski tahtaları saklayıp onlardan yeniden bir gemi yapsa, gerçek Theseus'un Gemisi hangisi olur? Soru gündelik örneklerde de karşımıza çıkar: Başı da sapı da yenilenmiş “dedenin baltası” ya da İngiliz komedi dizisi Only Fools and Horses'ta Trigger'ın süpürgesi. Trigger aynı süpürgeyi yıllardır kullandığını söyler, oysa başı da sapı da defalarca değişmiştir. Bu bulmaca, onarılan gemiler ve binalar için de, bir ömür boyunca değişen insanlar için de önemlidir.

Sources and further reading

Background reading: Ship of Theseus
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