“So it isn’t the original building?” I had asked my Japanese guide.
“But yes, of course it is,” he insisted, rather surprised at my question.
“But it’s been burned down?”
“Of course. It is an important and historic building.”
“With completely new materials.”
“But of course. It was burned down.”
“So how can it be the same building?”
“It is always the same building.”
Last Chance to See, Douglas Adams
This thought process is called The Ship of Theseus.
The version that has been most interesting to me in the past is the one concerning personal identity: Do you share a continuity or even an identity with the person you were a decade ago? I like to make use of the concepts of Past Me and Future Me a bit for decision making, so in one sense I’m accepting a continuity in time and identity. At the same time, those concepts always feel very artificial, useful as they may be. My current answer is a shrug, trying to convey “Maybe? Who cares, really, time is going to pass regardless of my thoughts, and I’ll deal with it as best I can. Go ask a philosopher.” – it’s a very expressive shrug.
That doesn’t mean that I’m finished with the question, thought. Recently, a more practically relevant version has been on my mind: How about groups of people? How long, and why do they maintain an identity? The question is not really that different from the individual identity question, I know, but it feels way more fun to reason about.
If you have a semi-regular meeting with friends, to play games or cook or exercise or debate, that will be a continuous group in your mind. How does it change when somebody misses a meeting? You’ll probably still see it as the same group, only with changed social currents. (But would you do the same if the person missing is usually a main reason for social cohesion?) Would you still see it as the same group if one person stops attending meetings completely? How about when a new person joins, either for a single meeting or regularly?
How does the answer change with group size? A political party has an obvious continuity even when a lot of people join or leave. (But maybe your smaller groups would have the same, if you could invest a lot of resources into signalling who you are, so that nobody will doubt or forget?) A school class is still the same class if some people are missing, get removed permanently, or new people join. (But maybe your smaller groups would follow that pattern, if you gave yourself a team name and an outside force made sure that you could not leave it behind.)
How does the answer change over time? The most tangible and relevant part of that question, to me, is family: Am I part of the same family as I was ten years ago? Is this the same family that I knew as a kid? I knew my great-grandparents, but is this still the same family? Is it the same family as 150 years ago? Would the answer change if my family cared less about cohesion? Would the answer change if I was part of a family with centuries of traditions?
Intuitively, labels and purpose are important to how this plays out. If you have a core purpose that group members generally agree on, the group retains its identity through more changes (in time and membership). Even though the group will feel differently, and its dynamics will differ, there will also be a feeling of continuity. The same goes for strong labels/corporate identity: If we meet for occasional football matches, the group will feel less “the same” over time or changing memberships than if we come up with a silly name and declare ourselves a team. If my family has a terribly old name and is proud of its ancestry, it will confer a default group cohesion bonus.
In some ways, good labels can replace some parts of a group purpose, because both help to answer the question “Who are we?”. Labels are the shortcuts that sooner or later develop if you have a shared purpose, but you can of course skip the purpose as much as possible and proceed to labels directly. Much easier, but also less stable, because if things get difficult, you’ll have to pour increasingly more effort into your presentation of identity (war propaganda, anybody?).
Last scattered thought: Being in a group where you are required for its identity can be a great feeling, but its also a huge responsibility, and for me often feels draining. At the same time, being part of a group where you are irrelevant to the group identity can be relaxing, but also depressing if you are only in groups like that. Balancing the two seems like a good idea, and how you do that depends a lot on your answers to the questions above.