Imagine that a Grecian museum has preserved the famous Ship of Theseus, the mythical king of Athens. The ship has been in their care for hundreds of years and, one by one, the wooden parts that make up the ship have each rotted and been replaced to preserve the ship. Eventually, the entire ship is made of new wood. Not a single piece of the original ship actually remains.
The captain’s bed, the sails, the ropes, the rudder — all of it has been replaced with new, identical, versions.
Is this ship still “The Ship of Theseus”?
So goes the famous philosophical thought experiment proposed by Thomas Hobbes and borrowed from ancient philosophers such as Plutarch, who wondered if you could ever step in the “same” river twice. The scenario raises questions of identity, sameness, and permanence.
Can this new, identical, ship really be called “The Ship of Theseus” when the king himself has not touched or ridden upon a single piece of this vessel?
If it is a new ship, at what point did it become a quantifiably different object? When one piece was replaced? When all were replaced? Or perhaps when the majority were replaced?
The paradox of The Ship of Theseus raises questions beyond the ethics of museum curation. As living beings whose cells are constantly replaced, human beings can be seen as partially restored ships. Humans, however, take their identity much more seriously than that of a ship.
If the very cells of our body are regularly restored, how can we be sure we’re the same people we were ten years ago? What about 10 months ago? Or 10 minutes?
The hair on our scalp is totally replaced every 2–7 years. Our fingernails regrow every eight months. Stomach cells, which are exposed to high acidity, are reborn quickly, every 2–9 days. Skin cells are rejuvenated every 2–4 weeks.
Some parts are more hardy, needing to be restored less often. Skeletons are replaced every 10 years, muscles every 15, and fat cells every 25.
Still, some of our parts will remain constant from the moment they are formed. We are born with most of the neurons in our brain that we will ever have. The core lens of our eyes, through which we see and experience the world (or don’t), is formed in utero and is never replaced.
With most of our parts being constantly replaced, but a few key cells remaining constant, it begs the question: Am I still the same ship?
In L. Frank Baum’s original The Wonderful Wizard of Oz, the Tin Woodsman was born as a human named Nick Chopper. The unfortunate Woodsman was cursed by the Wicked Witch, and piece by piece his flesh and blood parts were chopped off by his own ax and replaced by tin. All, that is, except his heart.
In The Tin Woodsman of Oz, the Tin Man contemplates what this means for his identity, eventually declaring he is the same person after all:
“No one can ever be killed. A man with a wooden leg or a tin leg is still the same man; and, as I lost parts of my meat body by degrees, I always remained the same person as in the beginning, even though in the end I was all tin and no meat.”
- The Tin Woodsman of Oz, by L. Frank Baum
While the Tin Man’s story is mystical, his tale rings true to those who have watched themselves change over the years, perhaps becoming someone unrecognizable.
Ten years ago, I would have described myself as weak, needy, and overly emotional. I was a teenager with low self-esteem in an abusive relationship with a man who once described me as a puppy.
“It doesn’t matter how many times you kick a puppy,” he said, “They keep coming back because they just want to be loved.”
Knowing him, he was probably actually was kicking puppies to test this theory.
Now, that weak teenage girl who couldn’t stand up for herself is unrecognizable to me. In fact, nearly all of my former weakness have become my current strengths.
I thought I was too weak, so I got strong and learned how to defend myself, my loved ones, and my beliefs.
I was told I was too needy, so I learned to be independent. Although I live with my current partner, I always maintain my own money, job, and resources. I will never be trapped out of need again. I’m the one who takes care of things.
I was perceived as too emotional, so I went to therapy and learned skills to handle my strong emotions. I may still feel things strongly, but most people wouldn’t know it. I stay cool and measured in a crisis.
Each of my parts has been replaced and restored — creating a better, shinier, healthier, new ship.
Most of the people who knew me ten years would hardly recognize the person I am today (in a good way, I hope). I’ve worked hard to get here. It’s clear, though, how the person I was shaped who I became. Likely, who I am today will shape who I am in another ten years. I’m a ship in progress.
My experience is not rare. A 2008 study in Current Directions in Psychological Science found that most people experience similar personality changes as they age:
“People show increased self-confidence, warmth, self-control, and emotional stability with age. These changes predominate in young adulthood (age 20–40).”
Some research suggests that people are actually able to intentionally change their Big Five personality traits (agreeableness, extraversion, neuroticism, conscientiousness, and openness) through intentional goal-setting over a period as short as four months.
A 2013 study in The Journal of Personality even suggests that living a happy, fulfilling life actually makes people more likely to experience positive changes to their personality (rather than the common assumption that a positive personality creates a positive life and those with negative personalities are doomed).
All of this suggests that there is a lot of hope for positive change. But if both our bodies and personalities are constantly changing, what does that mean for our individual identities?
Psychologist Erik Erikson’s theory of psychosocial development considers the formation of “ego identity” to be the key accomplishment of adolescence. Teens in this stage form their sense of self through comparisons to others, life experiences, and experimentation. Resolving this development crisis requires commitment to an identity. This can come in the form of developing interests, deciding on a career path, creating a sense of personal style, or choosing the social group with which to associate.
This stable sense of identity is necessary for success in Erikson’s next stage of life: “intimacy versus isolation.”
Erikson’s theory has been criticized for claiming that identity formation doesn’t end at adolescence, but failing to provide any details on the impacts of changing identities throughout adulthood. Research into Erikson’s theories has demonstrated that only about half of individuals reach “identity achievement” (the final stage of identity formation) by age 36. Most of us, it seems, are still working it out.
Finding a stable sense of self amongst the paradox of our ever-changing minds and bodies may feel impossible for some. But, perhaps, being open to and accepting of change and growth can be an identity in an of itself.
The Ship of Theseus defined itself by what it once was, and the Tin Man defined himself by who he became. I, however, choose to define myself by my ability to change. Whether it’s every seven years or every seven weeks, I consider having the chance to start over a blessing and accept change as a part of my identity.
M. K. is a feminist writer and activist with a background in mental health advocacy. Subscribe to get her latest posts directly in your inbox.