Teleportation
Suppose a device is created which would vaporize the atoms and molecules that form your body, transport them to another place in the world, then reassemble them exactly the way they were. Let's call this procedure type-A teleportation (this is a distinction I am making up, and it will be clear later in this post why it is necessary). We sometimes see these kinds of teleportation devices depicted in science fiction and fantasy. They are also occasionally mentioned as a thought experiment in the philosophy of personal identity, which is the branch of philosophy that revolves around, among other things, the question, "What makes you the same person you are at another time?"
We might answer that we know we are the same person we were yesterday because we have the same memories as the person yesterday. Let's call this the psychological account of personal identity. The psychological account is worrisome because memories and human psychology are fickle things. Say you're at a party, and you get blackout drunk – you drink so much alcohol that your brain no longer creates new memories. When you wake up in the morning, you are sobered up, but you have no recollection of anything that happened while you were intoxicated. It is here where the philosophy of personal identity actually has a practical application: it is important in some contexts to know whether you are still morally or legally responsible for things you do not remember doing. If, for example, you committed DUI while you were blackout drunk, should you be charged with that crime if you don't remember doing it? If it is true that personal identity hinges upon memories, then a philosopher who subscribes to the psychological account of personal identity might argue at the extreme end that you should not be charged with the crime because you are not the same person as the person who committed DUI. However, in practice, in most jurisdictions (e.g. the United States) you are legally responsible for DUI even if you do not remember committing it.
We might instead answer that we know we are the same person we were yesterday because we have the same body we had yesterday. Let's call this the bodily account of personal identity. The bodily account opens the door to worries and objections such as the ship of Theseus thought experiment. Imagine you have a ship made out of wood, and over time, some of the planks that make up your ship start to decay, so you replace them. Eventually, perhaps over the course of a few decades, you reach a point where all of the planks in your ship have been replaced, such that none of the planks that currently make up your ship were present in the original version of your ship. The question posed by Greek philosopher Plutarch in the late first century was, "Is it still the same ship?" Similarly, given that over time cells in the body die and are replaced by newer cells, then by analogy to the ship of Theseus, are we the same person over time if the atoms and molecules that form our body have been replaced over the course of decades? We might be able to resolve this issue by introducing a notion of continuity: we know we are the same person we were yesterday because we can identify a continuous chain of bodies that connected our body yesterday to the one we have today.
Type-A teleportation challenges this notion of continuity. Say you have a wooden ship that you want to take from one side of a continent to another. There is no passable waterway that would allow the ship to cut directly through the continent to reach the other side; the only seaworthy solution is to take the boat completely around the continent. However, that costs a lot of time and money; it would be far more economical to take the ship apart and transport its pieces by land to the other side of the continent, then rebuild the ship there. This is similar to type-A teleportation, in which a device vaporizes the atoms and molecules – the pieces of the ship that is your body – and transports them to another location, where they are reassembled like a ship. What is your intuition here? Once the ship is rebuilt on the other side of the continent, is it still the same ship as it was on the beginning side of the continent?
If you say yes, then this situation is worrisome if you subscribe to the bodily account of personal identity with that notion of continuity. The act of taking the ship apart creates a break in that continuity. Some philosophers might argue that due to this break, the ship that is rebuilt on the other side of the continent is in fact not the same ship, even though it has all of the same parts arranged exactly in the way the ship at the beginning side of the continent had it arranged. However, if we accept this, then we should also accept that if we use a type-A teleportation device, the person that is formed by the device at the destination is not the same as the person at the source. (By all of the laws of physics we have observed thus far, we are pretty sure that we cannot transport information from one location in the universe to another instantaneously; there must be some amount of time where the continuity is broken in order for type-A teleportation to work. The fastest speed of information transport possible is the speed of light in a vacuum: 299,792,458 m/s. See my blog post on special relativity.)
Those who subscribe to the psychological account of personal identity might say they have a satisfactory solution: the person at the destination is the same person as the person at the source because the two persons have the same memories. However, this solution is problematic because if we reject entirely that bodies are relevant to personal identity, then we run into issues with doppelgängers. If we can create a teleportation device that perfectly reassembles a human being from its constituent parts, then we can imagine creating a similar device that assembles a duplicate of a human being from duplicate parts. This is similar to the ship example, but instead of taking the ship apart and transporting its parts to the other side, an alternative solution is to build a ship that is a perfect duplicate – squeaky planks and all – on the other side of the continent. I think our intuition is rather clear here that the new ship is not the same ship as the original ship on the beginning side of the continent. However, if we perfectly duplicate a human, then the duplicate would have the same memories as the original. If you subscribe to the psychological account of personal identity, then would you say that the two are, in fact, the same person? What if we construct a different kind of teleportation device that vaporizes the original copy of your body and constructs a duplicate at the destination point without actually transporting the particles that originally formed your body? They're just atoms and molecules, after all; the oxygen molecule that I am breathing in has nothing that would distinguish it from the oxygen molecule you are breathing. It doesn't matter which token molecule we use, just how we assemble them. Let's call this type-B teleportation.
Type-B teleportation is scary. I don't want to teleport myself if I think there might be a chance that the device will just kill me and have a doppelgänger live the rest of my life. In this sense, type-B teleportation forms a rather neat bridge between the philosophy of personal identity and the philosophy of death. Death is also scary. As Steve Jobs said in his 2005 Stanford commencement speech: "No one wants to die. Even people who want to go to heaven don’t want to die to get there." What makes death especially scary is the uncertainty of it all. We don't know for sure how it feels to die because no one has ever lived to tell us that. Some people have had near-death experiences; survivors of cardiac arrest, for example, can claim that they were "technically dead" for a certain period of time. In type-A teleportation, in that brief moment when the particles that form your body are cruising to your intended destination, you are "technically dead". Your body has been disintegrated into a state in which no biological processes are taking place, and you lack consciousness. For this reason, perhaps the feeling of undergoing type-A teleportation is similar to the feeling of surviving cardiac arrest. The reasoning seems to make sense; however, I would challenge that idea by taking a closer look at type-B teleportation.
What is terrifying about type-B teleportation is that even though outside observers can interact with the person at the destination as if they were the same person as the person at the source, outside observers cannot guarantee continuing consciousness for the person being teleported. What does this mean? Suppose you use a duplication device on me. The perfect duplicate that is formed will have atoms and molecules in the exact same arrangement as they were when I stepped into the duplication machine; he will look like me, have the same memories as me, behave like me, and believe that he is and was always me (until we prove to him that he is a duplicate, of course). However, there is no way for the consciousness of my original body to perceive the thoughts and feelings of the duplicate body. The brain of my original body is not feeding the duplicate body any information, nor is the duplicate body doing the same for my original body. The two duplicate bodies will have two separate and distinct consciousnesses, and if we kill one of the bodies, then the consciousness within one of the bodies will cease to exist. This is exactly the situation that a type-B teleportation device would create: the device would create a duplicate body at the destination while simultaneously destroying the original body at the source. The consciousness of the original body at the source will end, while the duplicate will have, by my intuition, a newly created consciousness that simply has the memories of the original body.
If you accept what I have written so far, then the question I pose to you now is this: how is type-A teleportation different from type-B teleporation? Once your body is disintegrated, what's left is a soup of your constituent atomic particles. A duplication device would construct a duplicate soup of atomic particles that is the same in every respect to the soup of your constituent particles, such that if someone had to choose between the two soups and identify which one has the particles that originally made up your body, there would be absolutely no distinguishing features that would enable a person to do so. What compels the teleportation devices to use the particles that originally formed your body over the particles that didn't form your body? The particles are exactly the same. It is here where we reach a stunning conclusion: there is no difference between type-A teleportation and type-B teleportation.
Even though the type-A teleportation device is transporting your original particles to your destination, the body that is created at the destination will be a different person from the body that was disintegrated at the source, even though the body is a perfect duplicate. If we accept our intuitions before from type-B teleportation, I claim that your consciousness will end (i.e. you will die) as soon as your body is disintegrated at the source, while the body constructed at the destination will have a newly created consciousness that simply has the memories and the particles of your original body. For those who believe in the bodily account of personal identity with a notion of continuity, I think this is a victory. It is the break in bodily continuity that ruptures the sense of identity because we cannot guarantee that a person's consciousness will survive that break.
A few disclaimers, however. Much of this post was informed by a cursory study of philosophy at The Ohio State University in the spring of 2017 while dual-enrolled there in my senior year of high school. My instructor was Professor Richard Samuels. I certainly have not read up on much of the philosophical literature that already exists on this subject, so I am clearly not an expert. What I will say is that when it comes to teleportation, I would very much prefer some kind of wormhole / spacetime-warping solution that preserves the continuity of my body, rather than any kind of disintegration. Chaos Control, anyone?
We might answer that we know we are the same person we were yesterday because we have the same memories as the person yesterday. Let's call this the psychological account of personal identity. The psychological account is worrisome because memories and human psychology are fickle things. Say you're at a party, and you get blackout drunk – you drink so much alcohol that your brain no longer creates new memories. When you wake up in the morning, you are sobered up, but you have no recollection of anything that happened while you were intoxicated. It is here where the philosophy of personal identity actually has a practical application: it is important in some contexts to know whether you are still morally or legally responsible for things you do not remember doing. If, for example, you committed DUI while you were blackout drunk, should you be charged with that crime if you don't remember doing it? If it is true that personal identity hinges upon memories, then a philosopher who subscribes to the psychological account of personal identity might argue at the extreme end that you should not be charged with the crime because you are not the same person as the person who committed DUI. However, in practice, in most jurisdictions (e.g. the United States) you are legally responsible for DUI even if you do not remember committing it.
We might instead answer that we know we are the same person we were yesterday because we have the same body we had yesterday. Let's call this the bodily account of personal identity. The bodily account opens the door to worries and objections such as the ship of Theseus thought experiment. Imagine you have a ship made out of wood, and over time, some of the planks that make up your ship start to decay, so you replace them. Eventually, perhaps over the course of a few decades, you reach a point where all of the planks in your ship have been replaced, such that none of the planks that currently make up your ship were present in the original version of your ship. The question posed by Greek philosopher Plutarch in the late first century was, "Is it still the same ship?" Similarly, given that over time cells in the body die and are replaced by newer cells, then by analogy to the ship of Theseus, are we the same person over time if the atoms and molecules that form our body have been replaced over the course of decades? We might be able to resolve this issue by introducing a notion of continuity: we know we are the same person we were yesterday because we can identify a continuous chain of bodies that connected our body yesterday to the one we have today.
Type-A teleportation challenges this notion of continuity. Say you have a wooden ship that you want to take from one side of a continent to another. There is no passable waterway that would allow the ship to cut directly through the continent to reach the other side; the only seaworthy solution is to take the boat completely around the continent. However, that costs a lot of time and money; it would be far more economical to take the ship apart and transport its pieces by land to the other side of the continent, then rebuild the ship there. This is similar to type-A teleportation, in which a device vaporizes the atoms and molecules – the pieces of the ship that is your body – and transports them to another location, where they are reassembled like a ship. What is your intuition here? Once the ship is rebuilt on the other side of the continent, is it still the same ship as it was on the beginning side of the continent?
If you say yes, then this situation is worrisome if you subscribe to the bodily account of personal identity with that notion of continuity. The act of taking the ship apart creates a break in that continuity. Some philosophers might argue that due to this break, the ship that is rebuilt on the other side of the continent is in fact not the same ship, even though it has all of the same parts arranged exactly in the way the ship at the beginning side of the continent had it arranged. However, if we accept this, then we should also accept that if we use a type-A teleportation device, the person that is formed by the device at the destination is not the same as the person at the source. (By all of the laws of physics we have observed thus far, we are pretty sure that we cannot transport information from one location in the universe to another instantaneously; there must be some amount of time where the continuity is broken in order for type-A teleportation to work. The fastest speed of information transport possible is the speed of light in a vacuum: 299,792,458 m/s. See my blog post on special relativity.)
Those who subscribe to the psychological account of personal identity might say they have a satisfactory solution: the person at the destination is the same person as the person at the source because the two persons have the same memories. However, this solution is problematic because if we reject entirely that bodies are relevant to personal identity, then we run into issues with doppelgängers. If we can create a teleportation device that perfectly reassembles a human being from its constituent parts, then we can imagine creating a similar device that assembles a duplicate of a human being from duplicate parts. This is similar to the ship example, but instead of taking the ship apart and transporting its parts to the other side, an alternative solution is to build a ship that is a perfect duplicate – squeaky planks and all – on the other side of the continent. I think our intuition is rather clear here that the new ship is not the same ship as the original ship on the beginning side of the continent. However, if we perfectly duplicate a human, then the duplicate would have the same memories as the original. If you subscribe to the psychological account of personal identity, then would you say that the two are, in fact, the same person? What if we construct a different kind of teleportation device that vaporizes the original copy of your body and constructs a duplicate at the destination point without actually transporting the particles that originally formed your body? They're just atoms and molecules, after all; the oxygen molecule that I am breathing in has nothing that would distinguish it from the oxygen molecule you are breathing. It doesn't matter which token molecule we use, just how we assemble them. Let's call this type-B teleportation.
Type-B teleportation is scary. I don't want to teleport myself if I think there might be a chance that the device will just kill me and have a doppelgänger live the rest of my life. In this sense, type-B teleportation forms a rather neat bridge between the philosophy of personal identity and the philosophy of death. Death is also scary. As Steve Jobs said in his 2005 Stanford commencement speech: "No one wants to die. Even people who want to go to heaven don’t want to die to get there." What makes death especially scary is the uncertainty of it all. We don't know for sure how it feels to die because no one has ever lived to tell us that. Some people have had near-death experiences; survivors of cardiac arrest, for example, can claim that they were "technically dead" for a certain period of time. In type-A teleportation, in that brief moment when the particles that form your body are cruising to your intended destination, you are "technically dead". Your body has been disintegrated into a state in which no biological processes are taking place, and you lack consciousness. For this reason, perhaps the feeling of undergoing type-A teleportation is similar to the feeling of surviving cardiac arrest. The reasoning seems to make sense; however, I would challenge that idea by taking a closer look at type-B teleportation.
What is terrifying about type-B teleportation is that even though outside observers can interact with the person at the destination as if they were the same person as the person at the source, outside observers cannot guarantee continuing consciousness for the person being teleported. What does this mean? Suppose you use a duplication device on me. The perfect duplicate that is formed will have atoms and molecules in the exact same arrangement as they were when I stepped into the duplication machine; he will look like me, have the same memories as me, behave like me, and believe that he is and was always me (until we prove to him that he is a duplicate, of course). However, there is no way for the consciousness of my original body to perceive the thoughts and feelings of the duplicate body. The brain of my original body is not feeding the duplicate body any information, nor is the duplicate body doing the same for my original body. The two duplicate bodies will have two separate and distinct consciousnesses, and if we kill one of the bodies, then the consciousness within one of the bodies will cease to exist. This is exactly the situation that a type-B teleportation device would create: the device would create a duplicate body at the destination while simultaneously destroying the original body at the source. The consciousness of the original body at the source will end, while the duplicate will have, by my intuition, a newly created consciousness that simply has the memories of the original body.
If you accept what I have written so far, then the question I pose to you now is this: how is type-A teleportation different from type-B teleporation? Once your body is disintegrated, what's left is a soup of your constituent atomic particles. A duplication device would construct a duplicate soup of atomic particles that is the same in every respect to the soup of your constituent particles, such that if someone had to choose between the two soups and identify which one has the particles that originally made up your body, there would be absolutely no distinguishing features that would enable a person to do so. What compels the teleportation devices to use the particles that originally formed your body over the particles that didn't form your body? The particles are exactly the same. It is here where we reach a stunning conclusion: there is no difference between type-A teleportation and type-B teleportation.
Even though the type-A teleportation device is transporting your original particles to your destination, the body that is created at the destination will be a different person from the body that was disintegrated at the source, even though the body is a perfect duplicate. If we accept our intuitions before from type-B teleportation, I claim that your consciousness will end (i.e. you will die) as soon as your body is disintegrated at the source, while the body constructed at the destination will have a newly created consciousness that simply has the memories and the particles of your original body. For those who believe in the bodily account of personal identity with a notion of continuity, I think this is a victory. It is the break in bodily continuity that ruptures the sense of identity because we cannot guarantee that a person's consciousness will survive that break.
A few disclaimers, however. Much of this post was informed by a cursory study of philosophy at The Ohio State University in the spring of 2017 while dual-enrolled there in my senior year of high school. My instructor was Professor Richard Samuels. I certainly have not read up on much of the philosophical literature that already exists on this subject, so I am clearly not an expert. What I will say is that when it comes to teleportation, I would very much prefer some kind of wormhole / spacetime-warping solution that preserves the continuity of my body, rather than any kind of disintegration. Chaos Control, anyone?