What is the Ship of Theseus paradox?

Alright, no problem. This is a very interesting question, let's discuss it.

What is the Ship of Theseus Paradox?

Hey friend! This question might sound profound, but it's actually very relatable. Let me give you an analogy, and I promise you'll understand it instantly.

Imagine you have a bicycle you absolutely love, one your dad gave you when you were a kid. You named it "Little Wind."

You rode it for many years. "Little Wind's" seat eventually wore out, so you replaced it with a new one. Is "Little Wind" still "Little Wind" then? Of course it is.

Some more time passed, and the handlebars rusted, so you replaced those too. Is it still "Little Wind"? Absolutely.

Day by day, due to parts aging or getting damaged, you gradually replaced "Little Wind's" wheels, pedals, chain, frame... Until one day you suddenly realized that not a single part on this bicycle was the one you originally received from your dad.

So, here's the question:

Is this bike still the original "Little Wind"?

This is the core idea of the Ship of Theseus Paradox.

The name comes from an ancient Greek legend. After the hero Theseus defeated a monster, the ship he sailed on was preserved by the Athenians as a keepsake. To ensure the ship could be displayed for a long time, people continuously replaced its rotting old planks. Over time, all the planks of the entire ship had been replaced with new ones.

Thus, philosophers began to debate:

One side argues: Of course it is! Although its parts (planks) have all been replaced, its "identity," its design, its name, and the history and memories it carried, all remain. It has always been here, continuously maintained, and its existence is continuous.
The other side argues: Definitely not! Come on, a ship is made of planks. Now, not a single original plank remains; it's just another ship assembled from new wood, simply looking like the original.

The "Upgraded" Paradox That Makes Things Even More Complicated

Just as you're pondering this, someone proposes an even more mind-boggling scenario:

Suppose there's a collector who gathered all the old parts you replaced—the old seat, old handlebars, old wheels, old frame. Then, he used these original old parts to reassemble a bicycle.

Now you have two bicycles in front of you:

Bike A: The one you've been riding, gradually replaced with new parts.
Bike B: The one reassembled from all the original old parts.

So, which one is the real "Little Wind"?

Bike A possesses a continuous history and your memories.
Bike B is composed of 100% original materials.

This leaves you completely stumped.

This Isn't Just a Story About a Ship or a Bicycle

This paradox is so classic because it touches upon many fundamental questions in our lives:

About "You" Yourself: Science tells us that the cells in our bodies are constantly undergoing metabolism. Approximately every seven years, all the cells in your body are completely replaced. So, seven years from now, materially speaking, you will be completely different from who you were seven years ago. But are you still you? Of course. Why? Is it because of your memories? Your thoughts? Or your DNA (the blueprint that hasn't changed)?
About Organizations and Groups: If a band's founding members gradually leave, and new members join and continue to perform under the original name, is it still the same band? If all the players and coaches of a sports team are replaced, is it still the home team we support?

What is the Core of the Paradox?

It actually forces us to ponder an ultimate question:

What exactly determines something 'is itself'?

Is it its material composition? (All the planks, all the cells)
Is it its form/structure/memory? (Its design blueprint, your memories, the band's style)
Is it its historical continuity? (It has always existed, without interruption)

Therefore, the Ship of Theseus Paradox has no "standard answer." It's more like a thought tool, a wrench, used to pry open our preconceived notions about concepts like "identity" and "existence," making us think about the interesting logical puzzles hidden behind things we usually take for granted.