The Model Kit

In the physical sciences, experiments are designed to potentially falsify some hypothesis, which is an educated guess about some state of affairs in the physical world. Philosophy, in contrast, proceeds by way of thought experiments. A thought experiment is some imagined situation or puzzle that is designed to test the boundaries of a definition, a concept, or a system of ideas.

In classical antiquity, one of the most enduring thought experiments is known as the Ship of Theseus. In ancient Greece, the story goes, a ship meant to commemorate the voyage of the mythological hero Theseus was maintained by the people for a long period of time. Whenever some of the oak planks started to rot, they were replaced by new wood, and so after some years, very little of the original material of the ship remained. The question is, if every part of the ship has been replaced, is it still the same ship that made that first famous voyage? Or is it at this point a new and completely different ship?

This thought experiment is interesting because the parts of the ship are replaced little by little. If the original ship was just burned one day, and afterwards a brand-new ship just like the original was constructed, we would call that new ship a mere replica. It’s the gradual replacement of parts that makes this question something worth thinking about, because it mirrors the human condition. We are all changing little by little, and yet we consider ourselves to have a stable personal identity over time. This isn’t just about character growth or metaphorical change either, we are physically changing. The cells, biomolecules and fluids of the human body are constantly being changed out and refreshed. It is likely that relatively very few of the atoms currently making up your body have been there from early on. We are, all of us, walking and breathing Ships of Theseus.

Are we then completely different people then we were in the past? Sometimes when editing a video essay, rather than re-record to fix a mistake, the creator will add a voice over, joking “Hey, this is future me. I just wanted to correct the record on something that past me said right here.” And people often seriously say things like “I’m a completely different person now.” But it’s clear that we don’t really believe this. For one thing, you may have grown and changed as a person since you were younger, but “present you” still feels entitled to the returns of an investment that “past you” made twenty years ago. I may cringe at some of my old artwork as I improve over time, but if I hung a painting on the wall two years ago, I still want to be able to say that I, and not some other person who no longer exists, am the artist. Similarly, we hold each other accountable and make amends for wrongs we committed in the past. Perhaps we can say that we remain the same person on some level, but it is in the nature of people to change over time by incorporating little pieces of their environment into themselves through the simple steady process of living.

A final note on thermodynamics. There are three classifications of systems: open, closed, and isolated. All living things are open systems, meaning that we exchange both matter and energy with our surroundings. In truth, any ‘system’ is a construct, something that we define by separating it from the rest of the universe, which we define as the “surroundings”. Ultimately, there is but one isolated system: the universe in its entirety. The changes that we experience could be viewed as nothing more than the rearrangement of some small parts of this all-encompassing oneness. As Parmenides might say to Heraclitus (or Heraclitus to Parmenides), the more things change, the more they stay the same.