In this season of rebirth, as we attend annual celebrations and ceremonies that can seem at once familiar and strange, I’m reminded of an ancient paradox: the Ship of Theseus.

It’s said that the Athenians, keen to preserve the famous ship of the hero Theseus for future generations, took away the old planks as they decayed and replaced them with new ones. In this way, every board in the entire ship was eventually replaced with an identical copy.

This posed an intractable problem to the philosophers of the day: after all the work was done, and every board had been replaced, would it still be the ship of Theseus?

The answer, of course, is “yes and no.” The renovated ship preserved the design of the original — its “form,” if you will — down to the last detail. But none of the original materials survived, so in that sense, the new ship wasn’t actually the one Theseus sailed.

In the essay, “Theseus,” which was written around 75 A.D., Plutarch put it this way:

“…the 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.”

The persistence of meaning, despite physical evidence to the contrary, was a deep problem for early philosophers and remains one to the present, although these days we characterize it in terms of linguistics or the philosophy of language.

For example, we know intuitively what we mean when we use words like “grocery store,” but that first intuition doesn’t survive much scrutiny. Take the sentence, “The grocery store burned down, so they moved it across the street.” I know exactly what that sentence means, and so do you. But at the same time, it describes something literally impossible. A building burns to the ground and is then magically reconstituted across the street. The store itself is gone, reduced to rubble; nevertheless, it is now in a new location.

When we say “grocery store,” it seems we’re referring to two things at once: a physical place, yes, but even more importantly, the idea of that place — the “form” of it. The form is what survives the fire and can be moved across the street, unlike the physical part, the bricks and mortar.

There are some linguists, Noam Chomsky most prominent among them, who hold that words like “river,” “tree,” and “grocery store” may not actually have a physical component at all. In the Chomskian view, there’s no such thing as a river — outside of the concept we impose on an ever-changing, meandering body of water between two banks. Just like “grocery store,” “river” is a name we assign to an idea, not to an independent physical reality.

This is counterintuitive. The field of linguistics was built on the premise that we learn language by association. A mother points to a cow in a field and says to her baby, “Look, there’s a cow!” The baby sees a cow; he hears the word “cow;” the association is formed; and from then on, he knows what “cow” means.

Chomsky argues that language is far too complex — virtually infinite, in fact — for it to be learned by association. There has to be a innate human capacity for generating meaning, one that operates by form and not physical traits.

While it may be true that a child comes to associate the word “cow” with the big animal in the field, there’s something deeper going on, too. Let’s say you read that same child a bedtime story about a cow that has been changed into a stone by an evil witch. The cow spends most of the story, up until the last page, trapped in the form of a stone. Even so, the child on your lap will have no trouble looking at that picture of a stone on the page and believing — in fact, knowing — that it’s not a stone at all; instead, it’s actually the poor, bewitched cow!

Apparently, even very young children have the ability to keep the “form” of a thing in mind, and will adamantly call a stone a “cow,” despite all physical evidence to the contrary.

But there are limits to the mind’s ability to contain this kind of paradox. In the seventeenth century, the philosopher Thomas Hobbes proposed an addendum to the Ship of Theseus: what if, Hobbes wondered, the replacement of the rotting boards took place at sea while the hero was sailing home? As Theseus’ carpenter replaced each board, the old one would be tossed to the waves. And what if, by chance, the ocean currents cast all of the discarded boards onto the shore of a deserted island, and some shipwrecked carpenter assembled a ship out of all of the boards that washed up? Would that be the true ship of Theseus? Or would it be the nearly identical ship Theseus was sailing somewhere out in the ocean? Both? Neither?

These are questions beyond human understanding.

As one year ends and we replace old days with new days, rebuilding the ship of our lives with new materials, let me leave you with a few words that also pass all understanding, and invite you to join me in considering the unchanging and eternal truth they represent: starlight, birth, loving-kindness, peace.