Identity Over Time and Mr. Potato Head

In philosophy, there is a discussion that has been occurring for thousands of years about the persistence of identity. It is easily summed up through the classic example of the Ship of Theseus:

This is a puzzle that has been around since antiquity, probably later than Heraclitus, but not much later. It first surfaces in print in Plutarch (Vita Thesei, 22-23):

“The ship wherein Theseus and the youth of Athens returned had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their place, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same. "Plutarch tells us that the ship was exhibited during the time [i.e., lifetime] of Demetrius Phalereus, which means ca. 350-280 BCE. (Demetrius was a well-known Athenian and a member of the Peripatetic school, i.e., a student of Aristotle. He wrote some 45 books, and was also a politician).

The original puzzle is this: over the years, the Athenians replaced each plank in the original ship of Theseus as it decayed, thereby keeping it in good repair. Eventually, there was not a single plank left of the original ship. So, did the Athenians still have one and the same ship that used to belong to Theseus?

This is even more important when it comes to ourselves: as we are replaced by new cells (or even organs or limbs), are we still the same person?

But rather than focus on such serious examples, let's think about Mr. Potato Head. Specifically, let's focus on the Mr. Potato Head of the Toy Story films. Mr. Potato Head can exchange his parts and yet he is clearly the same person: switching in his angry eyes or even using his eyes remotely and yet he's still the same curmudgeon. After watching *Toy Story 3 *my wife and I realized that Mr. Potato Head is even more persistent than we thought: he can replace his body with a tortilla and still maintain his identity (similar to how the original toy needed a real potato for the parts). Clearly, Pixar has sewn this problem up neatly, at least for toys. When it comes to Mr. Potato Head, his identity is something amorphous and hard-to-define: in the absence of his body, or his body parts, he still remains Mr. Potato Head. The Mr. Potato Head of Pixar seems to be imbued with a plastic soul.

It turns out that I am not the only one who has thought about these issues. Julia Galef, of Rationally Speaking, has thought about this as well, and in much greater detail, even recognizing certain additional complications:

Do you see where I'm going with this? The fact that this physical communication between Mr. Potato Head's body parts was necessary reveals that the separate parts aren't being controlled centrally by a single mind. The only conclusion left for us to draw is that each part is controlled by an autonomous mind. Which then raises the question: when Mr. Potato Head's parts are all assembled as per usual in his potato-body, does he have one mind, or does he consist of a complex collaboration between independent minds?

So what is the answer to all of this? We already have toy problems to highlight issues in philosophy; we now need more toy philosophy.

Top image:Sam Howzit/Flickr/CC