A similar thought experiment spurs the same style of thinking using a different metaphor. Donald Davidson’s “swamp man” is also about identity. It goes like this: a man is traveling through a swamp and is struck dead by lightning. At the very same instant the lighting also strikes the molecules in the swamp and rearranges them into an exact physical replica of the man, who then continues to live the first man’s life (did we mention how painfully contrived thought experiments can sometimes be?)
The question is about the nature of the swamp man’s mind. What kind of mind would he have, given that everything about him is physically the same as the first man? Davidson claimed that the swamp man would not actually be a person, since he would have no history and no memory; he is not a genuine being and anything he said would have no real meaning. He would appear to be interacting in all the normal ways, but he has no “causal history” and nothing to remember, since he never experienced it in the first place. He is just something that rose from the swamp and happens to resemble you…in every single way. But does that mean that you are nothing but your physical manifestation? No, probably not.
This is akin to saying that a new ship built out of bits and pieces of the old ship is not really the old ship, since it has no sense of history, context or continuity. Even if all the parts are the same, the first ship might have had a long history that the new one simply lacks. Does that mean that we are only our experiences and neuronal connections? No, probably not.
This swamp man looks like you, is conscious, and for all intents and purposes is you on a physical level. But is he you?
We can understand the swamp man as something of an addendum to Theseus’ ship, which acts as evidence that the identity of a whole is so much more than its components. It’s essentially asking what happens to the ship’s personality, history, memory and experience. With inanimate objects, we tend to think in terms of structure, function and components. But with humans, we are clearly made of more than our physical parts, which the swamp man experiment shows quite clearly.
In fact, this train of thought makes it quite obvious what we consider to be our identity—t’s not about our bodies, it’s about our personalities, experiences, and patterns of thought. If we cut out our brains and put them into host bodies, we would probably still consider that organism to be us.
What this thought experiment teaches us is to whittle down our suppositions and theories to really arrive at what we believe, what we claim, and what we assume. This thought experiment is like a refinement of Theseus’ ship, acting like a scalpel to further narrow down the question: What is a person?
Beam Me Up, Scotty
A simpler version is to ask whether the people who go through the “transporter” in Star Trek (dissembled and reassembled on an atomic level) are still the same people or entirely new, different ones. The difference here is that the person is somehow transported with all their memories and ideas intact. Would you consider the swamp man fundamentally different from a person that has gone through a transporter? (A related question—how on earth could a transporter transport people’s memory and experience? Where are they, if not in the cells and atoms of the body?)
This thought experiment is also called “Parfit’s transporter” (sci-fi and speculative philosophy are close friends with a long and tangled history). It doesn’t matter that transporters aren’t real—yet. The creators of Google have frequently claimed they were inspired by Star Trek’s gadgetry, as though sci-fi paved the way for regular sci to follow. What matters is what they can show us.
Asking these questions allows us to have more robust and sophisticated answers to questions like what happens to “us” after we die, whether we’d be the same people following a coma or traumatic brain injury, or whether we’re going to be the same people at the end of life as we were at the beginning.
When you chew over these questions long enough, you start to see that the question of identity is one of continuity from the past to now—of something that persists despite change and movement through this thing we call time. Thought experiments can help us better understand this continuity, what it is and isn’t.
You might decide that identity is a bodily phenomenon, a question of continuity of the literal parts making up an entity. Then you would be faced with certain consequences: that at some point you didn’t have an identity, and you will cease to have one at some point, too (i.e. after your parts disassemble and you die.)
You might instead say that continuity in soul or spirit constitutes identity. But then you would have to figure out exactly what this invisible, intangible substance really was, that somehow inhabited the physical form—and there are problems with this too, to say the least!
You could say that continuous identity is about stable patterns of behavior and personality, and that the emergent properties of your constituent parts acting as a whole are what amounts to your personality. But even people who believe this still make room for the fact that personalities, beliefs and ideas still do change, leaving us back at square one.
You could say that the idea of identity is itself a falsehood, or a trick of language, a little like you could argue that inches, degrees Celsius or the border of Mexico don’t really exist, we merely behave as if they do.
The question here is not which perspective is correct, but rather to give ourselves the chance to explore the consequences of adopting one or the other viewpoint. If you behaved as though you were a collection of physical parts animated by a spirit that persisted after your physical body died, you might take different risks, interpret life events differently, have different goals, deal with adversity differently, seek out a different occupation, and fear different things. In short, the way you think about yourself has the most profound of implications—it draws the limits and bounds of how you live.
Knowing what you know about Theseus’ ship, about the transporter analogies or the swamp man story, what would you like to use going forward, and why? Practice a little deliberate, conscious self-determination and try on the thoughts and mental schemes that you wish to inhabit, rather than merely occupying whatever model you’ve found yourself in by habit or accident.
Thought experiments like this can seem pointless or unconnected to any real-world phenomena, but they are more ubiquitous than you think. Take a look at the following questions, and ask yourself what your answers tell you about your working models and beliefs:
Where does life begin? It could be at conception, at the first detectable heartbeat, or the moment a baby is born. But then, when is a baby a full human being? When does it have personhood—is this something it was born with, or will it grow into it?
On the other end of life, when does a person officially die, in your opinion? It may be once they stop breathing, thinking or having a heartbeat. But why these signs of life and not others?
Do people have souls? What about personalities? Is there any difference between a soul and a personality, and if so, what is it?
Can people fundamentally change who they are?
Have you changed since this morning? What about over the course of a week, month or year? What does all this say about the potential for personal development?
If someone experienced a traumatic event, the trauma essentially follows them precisely because they feel as though they are the same person as the one who experienced the trauma. The event is passed. What carries into the present, however, is the identity the person retains of being a victim or survivor.
As a practical example of how identity thought experiments can enrich our world, consider two people who have undergone a trauma. One conceives of their identity as fluid, up for negotiation, and constantly evolving. The other sees themselves as fixed and non-negotiable. After a trauma, the former is more likely to say, “I’ve moved on; I’m a different person now” while the latter is more likely to say, “I’ll always be a victim of such-and-such injustice and nothing I can do can change that. It’s who I am.”
Thinking deliberately of identity also gives you the chance to enter into a “growth mindset”—i.e., conducting yourself as though you can always learn, develop and change. This means you can admit when you’re wrong and actually improve, which is much harder to do if you sincerely believe your personality is fixed and spells a destiny that you can never really change. Depending on how you answered the questions above, your self-belief could pave the way for freedom or apathy, for being proactive or passive, resigned or open-minded and curious. Isn’t it true that people only live within the limits they first set for themselves?
The way you think about yourself affects how you process risk, adversity or opportunity. It tells you how to interpret your experience, how to plan for the future, how to talk about the past. There are arguably as many ways of conceiving of the self as there are selves.
The question is, which way of thinking about yourself offers you the most control, optimism, understanding, beauty, insight? Which one feels best? Makes the most sense? Matches with the world you actually perceive in front of you? Is there perhaps another way of conceiving of the entire endeavor that strikes you as preferable? These are all realms of questioning you might not have explored without the original poke from a few seemingly silly thought experiments!