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RWDevCon Inspiration Talk – Identity by Alexis Gallagher

Alexis shares his thoughts on identity, taking ideas from moral philosopy and programming and examining them through the lens of his own experiences.


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Note from Ray: At our recent RWDevCon tutorial conference, in addition to hands-on tutorials, we also had a number of “inspiration talks” – non-technical talks with the goal of giving you a new idea, some battle-won advice, and leaving you excited and energized.

We recorded these talks so that you can enjoy them, even if you didn’t get to attend the conference. Here’s our next talk – Identity by Alexis Gallagher – I hope you enjoy!


“I enter the teletransporter. I’ve been to Mars before, but only by the old method: a spaceship journey taking several weeks. This machine will send me at the speed of light. I merely need to push the green button.”


“Like others, I’m nervous. Will it work? I remind myself what I have been told to expect. When I push the button, the scanner here on Earth will destroy my brain and body while exactly recording the state of all my cells. It will transmit this information by radio.”

“Traveling at the speed of light, the message will take about an hour to reach Mars where the replicator will create out of new matter, a brain and body exactly like mine. It’s in this body that I will awake.”

“I believe this is what will happen, but still I hesitate, but then I remember my wife grinning this morning when I confessed to her my hesitation about it. She reminded me she has often been teletransported, and there is nothing wrong with her.”

“I press the green button. As predicted, I lose consciousness and seem a moment later to regain consciousness, but in a different cubicle. Examining my body, I can find no change at all. Even the cut on my upper lip where I was shaving this morning is still the same.” (Taken from Reasons and Persons by Derek Parfit.)

Hi, I’m Alexis. I haven’t actually been to a teletransporter, but I think it’s a really interesting to discuss a parallel that I noticed. In this talk, I want to tell you about that parallel, and then I also wanted to offer what’s really a personal reflection on it.

Some of this is a bit philosophical. Some of it is a bit personal. I hope some part of it speaks to you.

Derek Parfit Defines The Transporter Problem

Derek Parfit wrote the passage I just read, which begins a discussion of the transporter problem. He wrote this in a book called Reasons and Persons in a chapter called “What We Believe Ourselves To Be.”

Attribution: Wikipedia.org

Attribution: Wikipedia.org

Parfit worked on that book for 15 years, and when it came out, everyone loved it. Philosophers have said that it’s the most significant work in moral philosophy since 1837.

I first heard Parfit lecturing about 20 years ago, and in-person he has exactly the sort of unworldly air you would expect from a legendary moral philosopher. He has dramatic white hair. You could say he’s sort of an alpha nerd in the world of moral philosophy.

Screen Shot 2015-06-21 at 9.37.04 PM

The transporter problem is intended to clarify ideas about personal identity. Remember, the transporter consists of a scanner and a replicator. The scanner destroys your brain and body, turning it all into information. Basically, it’s like NSCoding, but for your body.

The question is, how do you feel about NSCoding for your body? When you walk into the transporter, do you hesitate before you push the green button, or is that something you are happy to do?

Do you feel like the transporter is killing you and creating a new person, or do you feel a transporter is just moving you by moving your body? Is it the same you coming out of the transporter?

Defining Terms To Help Us Understand The Problem

That comes down to what makes two persons the same person. To consider this, Parfit distinguishes between two ways that any two things can be the same.

One way things can be the same is if they are qualitatively identical. This is a piece of jargon from analytical philosophy. This just means that things are exactly alike. They are alike in their observable qualities.

  • One example would be mass production. If I have a factory making ping pong balls, and two ping pong balls come out, they are going to be qualitatively identical.
  • Another example is identical twins. If two identical twins are atom for atom or cell for cell identical with each other, you could say they are qualitatively identical, but that doesn’t make them the same person. Fred Weasley is not the same person as George Weasley, even if they look exactly the same, even if they are physically the same.

There’s a sense in which they are identical, qualitatively identical, but there’s another sense in which they are not. That other sense is called numerically identical. We say two things are numerically identical if they are actually one and the same thing.

  • Imagine your factory with mass production of ping pong balls. It’s spitting out 100 a minute. If you looked at one of them and just followed it with your finger to keep track of it, you always know that one is the same as itself.
  • Another example, thinking again of twins, you are always the same as yourself through time. One thing is always the same as itself. Fred Weasley at 10 is the same as Fred Weasley at 20. It’s the same entity.

This idea, with this distinction in-hand, we can restate the transporter problem. Remember, by definition, the transporter preserves the exact state of all your cells. By definition, the person leaving the transporter is qualitatively identical to you. That’s what the transporter does.

That leaves the big question. The big question is, is it the same person walking out? Is that person numerically identical to you?

Am I The Same Me?

That’s really a question about what kind of thing a person is. From inside, I feel like it’s the same me through time.

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I feel like it’s the same me who is trying to pick up the pumpkin. It’s the same me who was in college with an umbrella indoors for some reason. I feel like it’s the same me as the me right now, that all of these are the same entity.

That’s the feeling, but what makes that feeling true? Is it just about physical continuity through time, like the same criterion that you would apply to a rock, or is it continuity of my memories? This is what John Locke believed, that what makes us the same person through time is you can form a chain of memories going back all the way to as soon as you started having memories.

Parfit considers many theories. I’m not going to review them all here. I just want to get to showing you the parallel that I promised.

Clojure Defines An Identity As Having Many States

Rich Hickey is the creator of Clojure, which is a very cool Lisp dialect that runs on the JVM. As you can see, like Parfit, he has very dramatic hair. I guess you could say that Rich Hickey is an alpha nerd in the world of somewhat esoteric programming languages.


I was reminded of Rich Hickey and of Parfit’s discussion of identity when I heard Hickey talking about this:

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This is Clojure’s model of time. It’s used to model change in the language. Hickey, I think he’s the only person that does this, defines identity as a noun to mean any continuously existing thing in the world, like a person, for example.

Every identity has a state that changes through time. A value, in the language, a value captures a snapshot of the state at some moment. The identity is that loop you can use to see the sequence of values that moves through time.

One of those values is a state. A value is just like the record captured by the scanner here on earth. It’s a snapshot of a moment.

Screen Shot 2015-06-21 at 9.40.03 PM

People wonder what value types are for in Swift. Quick parentheses. You can think of value types as things that are really good for expressing values.

If you were going to use the Clojure model, use a reference type to describe an entity, like a person, but then that entity holds a value. It’s quality is right there at that moment in time, and that value can change, but that value, that snapshot, is always sort of mutable.

This is the parallel I noticed.

Screen Shot 2015-06-21 at 9.40.27 PM

Numerically identical is to qualitatively identical just as same identity is to equal value.

So What Is Identity?

Later I learned that the Clojure model is actually echoing earlier work, I think.

This gentleman here is Eric Evans. He wrote a nice book called Domain-Driven Design around 2005.

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He talks about the distinction between entities and value objects. It’s a very similar distinction. I think in retrospect, it’s not too surprising. You arrive at this kind of distinction between an entity and a value or a snapshot of it as soon as you try to specify exactly what is staying the same about something that might be completely changing.

What’s the answer? What is staying the same about something that might be completely changing? To be honest, I don’t know.

I think the Clojure model and Parfit’s model and what Evans have to say, I understand exactly what they are saying when they are talking about the snapshots, when they are talking about values or moments or qualities, but I feel like all of these models get slippery and tricky exactly when they try to nail down conceptually what identity is.

One of my takeaways is that identity is a fundamentally subtle and slightly problematic concept. When I was looking into this, I found the Stanford Encyclopedia of Philosophy has 10,000 words just defining “identity” in general, and then another 10,000 before it handles the special case of identity as it concerns people.

That’s why this parallel speaks to me because what it suggests is that the niggling puzzles that we encounter when we are trying to do data modeling in our applications are not trivialities. They are actually the protruding, tiny edge of much more profound, subtle issues under the surface that people can wrestle with and have thought about for a long time.

From My Own Experience

Let me offer my personal perspective on this also. This is a picture of San Francisco, specifically these are The Painted Ladies.

Screen Shot 2015-06-21 at 10.53.44 PM

They are Victorian houses that people probably know from the opening of Full House.

This is near Alamo Park, which is not far from where I live. I grew up in San Francisco. Then I moved away, and after about 20 years, I moved back. That was about a year and a half ago.

When I moved back, for months, I had the eerie sort of spooky feeling that I was not in the real San Francisco anymore. In other words, it seemed like someone had created a perfect replica of San Francisco.

Screen Shot 2015-06-21 at 10.54.02 PM

The old and new San Franciscos seemed to be equal, but not the same. It seemed like the new San Francisco was qualitatively identical. The streets hadn’t changed that much, but it wasn’t numerically identical, like the essence of San Francisco somehow was gone from it, like it was a perfect replica.

I think this is not an uncommon experience. We often have it connected to places that were really powerful early in our lives, like our home from childhood or a place where we had powerful friendships that really touched us.

I think it’s because of a feeling that was in us, at that age, and then when we get older, our feelings change and we come back and our feelings don’t match the place anymore. Then the place seems like its soul is missing.

It seems eerie, like you are meeting a familiar friend and they don’t recognize you anymore. When we visit the place again, our own emotions are different, and so there’s no fit. It’s nostalgic, and it can be unpleasant, like the place doesn’t recognize you.

My Childhood Identity

It’s not just about places. When I was walking around San Francisco having this feeling, I also had the feeling that I wasn’t myself anymore. I had the feeling that I wasn’t the real Alexis, almost as if I had been replicated.

Screen Shot 2015-06-21 at 10.54.20 PM

Like it wasn’t me; like I was the ghost of myself. It kind of sucked. Why was I feeling that way?

Before I say that, let me show one more gentleman. Does anyone recognize this man?

Screen Shot 2015-06-21 at 9.38.34 PM

Yeah, I see nods. This is Richard Feynman, the Nobel prize-winning physicist. He also wrote a very nice book of anecdotes which made him very popular. Lots of people read it.

Of course, he’s a canonical alpha nerd with dramatic hair. He won a Nobel prize. You can’t get more alpha nerd than that. Pretty good hair!

I think the reason I was having the feelings I was is because the last time I lived in San Francisco, I was graduating high school, and at that time, I was 100% obsessed with theoretical physics. Maybe I was 200% obsessed with theoretical physics.

In my mind, I thought Feynman was the coolest thing in the world. San Francisco, for me, for 20 years, had been captured in wax as a place that had these emotions of child Alexis, really interested in physics, wanting to be a physicist. Now I was coming back, and I was grown man Alexis with a family making software.

It was that mismatch that felt disturbing. It was that mismatch that made me feel like this wasn’t the real me. This wasn’t how things were imagined at some point.

Is Your Identity Destroyed Or Just Changed?

I’m going to quote for Derek Parfit once more, when he’s discussing different kinds of identity. He describes one possible notion here: “Suppose that an artist paints a self-portrait, and then by repainting turns this into a portrait of this father. Even though these portraits are more similar than a caterpillar and a butterfly, they are not stages in the continued existence of a single painting.”

“The self-portrait is a painting that the artist destroyed. In a general discussion of identity, we would need to explain why the requirements of physical continuity differs in such ways for different kinds of things.”

Parfit dismisses that notion of identity. He raises it just to blow it off as being irrelevant for people, because he’s got this very philosophical thing he’s trying to get to, a person as a kind of object, and what does that mean?

Actually, that description strikes me as a very evocative description of the normal process of aging and moving through life. Your story about yourself changes. You erase pieces of yourself.

If the changes are big enough, you are likely to feel that you have become a new kind of thing at some point. Are you being turned into a butterfly, or are you being destroyed?

Or, is it the same thing? How do you know?

These are CT scans of a caterpillar in its chrysalis.

Screen Shot 2015-06-21 at 9.35.32 PM

I think if you asked a caterpillar if it wanted to do this before the process started, it would probably say, “No thank you.” It would say, “This looks like what you are describing is severe damage to my internal organs over ten days. This is a bad idea.”

To be honest, frustration and disappointment is also part of this story, part of how we interpret these things. I’m sure if had been walking around San Francisco and I met my 16-year-old self, his reaction would be, “What? You’re not a physicist? What happened?”

At the same time, he’d also think iPhones were pretty cool. iPhones didn’t exist when I was 16. It really doesn’t seem like he had all the information necessary to make all the decisions about how my life was supposed to go and how the world is supposed to be.

I Feel Like An Impostor

This also reminds me of discussions you see about impostor syndrome.

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This usually comes up in the context of groups that are under-represented in technology, but of course, it’s a universal experience of the human condition:

  • feelings of self-alienation
  • feelings of personal frustration
  • feelings of people not understanding you
  • feelings of the context not being right for you in some way

These feelings are available to everybody.

For me, personally, I could tell you that roughly every four to six months I have this experience. I am working on something and I have the feeling when I’m working with software that I have no idea what I’m doing because I discover something where I realize it was very basic, and I should have known it, and somehow I never managed to learn it so far. At those moments, I have feelings of paranoia and frustration and anger with myself that I still don’t know how to do this stuff right.

Then I reflect that every four to six months I’m doing something substantially new, so I’m always operating in an area where, to some extent, I don’t know what I’m doing. It’s a big world. That’s part of it.

That doesn’t change the feeling. I just need to notice the feeling and not take it too seriously and remind myself that there are other reasons to believe I’m not an idiot, even though I feel like I’m an idiot at those points.

Part of me still wonders, would I feel more real, would I not have these feelings, if I had dramatic hair and was an alpha nerd in a black and white photo? The alpha nerd snapshots don’t feel what it feels like inside the snapshot.

Even Feynman in his books writes about periods of feeling like an impostor when he was starting his teaching responsibilities for the first time and was also trying to do research and was developing a curriculum. He writes about running away into the library and reading fairy tales of One Thousand And One Nights because he was too stressed out by it all.

Three Claims To Assist In Moving Forward

What does all this add up to? Let me try to wrap it up with three claims I can offer.

  • Claim #1: Identity is a perspective. It’s a slippery concept. It’s surprisingly hard to pin down in any objective way. In the world, we impose identity on things by deciding to see them as connected through time. It’s not that different in our hearts. We tell stories about ourselves to tie our lives together into one thing. We feel about as coherent about as ourselves as we decide to feel.
  • Claim #2: Reality is the moments. However you end up defining identity, the brute fact that you are working with, the little atoms or values that you are tying together, or the snapshots, the moments; this is what’s actually there. This is what we can be certain of.

    So don’t waste time feeling like an impostor. If at this moment, you are doing the work, then you are actually doing the work. It’s as simple as that.

  • Claim #3: Time is a transporter. Whatever your wishes, whatever your plans for yourself, you will change along the road. You will change a lot. Eventually you will die, which is a very big change.

    There’s no use resisting change because it’s still happening. Every moment, the cells inside you are being modified and recycled and some are dying. The matter that are constituted of, some of that you are shedding. You are taking in new matter as you eat.

    You are being destroyed and re-created moment-to-moment even if you are just standing still. Even if you do not step into the transporter, time is a transporter. It’s destroying and re-creating you.

My advice, and I realize this sounds very cheesy, but I believe it, is to embrace that. Step into the transporter, press the green button, go somewhere new. Go to Mars.

Screen Shot 2015-06-21 at 10.55.31 PM

You don’t have a choice because you are moving forward anyway.

That’s my thought on identity.

Note from Ray: Did you enjoy this inspiration talk? If so, sign up to our RWDevCon newsletter to be notified when RWDevCon 2016 tickets go on sale!


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