The Mars Teletransporter, introduced by Derek Parfit, is a paradoxical and philosophically trying beast whose resolution requires that we dive into and criticize current philosophical frameworks. As the argument reaches its terminus, we will have developed and tested a counterintuitive explanation of who we are that can bear up to paradox. That said, on this strange and winding path to new explanations, the article here is the bicycle on which you can transverse the path: It can give leverage to your efforts, but the work of conjecturing ideas that jibe with my logic and your style is yours to be make.
Let’s start with the easy problem.
In front of me is a teletransporter. It works as follows. On Earth, the machinery reads my complete physical and mental condition, down to the cell. It then vaporizes me and relays my exhaustive information at the speed of light to a universal constructor on Mars. That constructor builds a person with my exact information, such that it shares my exact psychological life and physical makeup. So is this Martian copy me, or did I die?
I might have died, but this situation is just as good as surviving.
Imagine walking through a genuine teleporter to Mars. If you did so, the you before stepping into the teleporter and the you afterwards would differ in effectively just location and time. The same is true for the teletransporter that vaporizes and constructs. The me before and after will share everything that matters in survival. The body, identity, psychological continuity, intellectual personhood and consciousness by which I may define myself are identical in the Martian copy. Indeed, regardless of whether you maintain physicalism, panpsychism or conscious realism, even my ‘copy’ and I have consciousnesses that are identical, if there even can be a difference between two persons’ consciousnesses. (The long footnote is for those who disagree with that statement.) So, by any standard, the Martian copy is me.
Okay, the ‘copy’ is me, but would I die? In the sense that my exact consciousness and psychology would remain in this universe, I would not die. Not convinced? If not, the reason you think I would die is not a consequence of what happens in external reality, but rather in our minds. The mental models that represent us describe us as physical objects, so according to it, destroying the body means destroying us. But this is not quite right; we are at bottom not physical matter but a moment of information produced by the brain. That moment of information is encoded by the physical body, but the information is independent of substrate, and can thus be encoded identically in our Martian ‘copy’. We, information encoded equivalently in the original Earthling and Martian copy, therefore survive, even though our bodies, the matter in which the information was priorly instantiated, are destroyed. I think this is just as good as surviving.
And yet we might still feel hesitant to vaporize and duplicate ourselves. However, assuming that the teletransporter works invariably, that hesitency is an artifact of our what our mind is accustomed to (staying instantiated as the same body throughout life) rather than logical judgement of what happens in the world the world. So, jumping in the teletransporter would take an act of defiance against the normal way we see the world, but it is a rationally tenable action.
Now, when the teletransporter abstains from vaporizing us, the philosophy gets more juicy.
I walk through the Martian teletransporter at time `t1`. It copies and relays my information to the constructor on Mars, which creates a copy at time `t2`. The Earthly original trots out of the teletransporter at `t2` as well. Both the original on Earth and my identical copy on Mars now coexist. How can there be two of me surviving? Which one has claim to being the original person, whom I will call Adam?
What makes two people, each existing at a different time, the same person? Presumably some relation between them. The literature calls this constellation of links that include memories, beliefs, character and goals psychological connectedness. If two people have strong links of psychological connectedness, they are psychologically continuous. And here we reach philosopher Derek Parfit’s criterion of identity: “`X` at `t1` is the same person as `Y` at `t2` if and only if `X` is uniquely psychologically continuous with `Y`”. Uniquely means `X` is psychologically continuous with `Y` and no one else is. So, using this criterion in our problem, the identity is not transferred to either of my copies at `t2`, because both are psychologically continuous with Adam.
This means that the identity of Adam survives and is transferred to the Martian if the Earthling were vaporized, but it ceases to be if the original Adam avoids vaporization and is copied. We have reached a highly awkward situation. If we value identity at all, the Earthling and Martian would be incentivized to destroy each other, so they can regain the original identity of Adam. But that smacks of absurdity.
This dilemma warrants an evaluation of why whe value identity in the first place. Identity is uniqueness plus psychological continuity. The way out is to devalue uniqueness, thereby taking identity as not important for what matters to us. We shouldn’t care about surviving, but rather whether there will be an entity that is psychologically continuous with us. That means that the original Adam should not care whether he is continued by himself on Earth or his copy on Mars, since they are equivalent to him in what matters: same in consciousness, character, memories and every other meaningful trait. Accordingly, identity is just not what unites our lives. There are factors that unite one’s life, but they are a messy and many-layered cheesecake, not a flat and single-decked pancake.
In his recent book A Thousand Brains, neuroscientist Jeff Hawkins argues against mind uploading, a situation essentially equivalent to the teletransporter. Hawkins says we would not like the result because the upload would create a different person, not us. I think he has not considered the philosophy sufficiently. We can replace “teletransporter” to “upload”, and the argument runs in parallel: There would be two different entities, but that’s just as good as surviving, unless you think that identity figures at all at all in our deepest values.
So, would I step in the teletransporter? Yes. My intuition and emotions would balk at the thought of vaporization; jumping in the teletransporter is act of defiance against the normal way we see ourselves as bodies rather than information states encoded by those bodies. However, reason is more perspicacious than emotion, and, rationally, we should have no qualms in using it to override the latter’s inexplicit theories. So yes, I would jump in the teletransporter and reap the benefits of travel at the speed of light.
With some of the philosophical scruples of the paradox ironed out, it seems the teletransporter can be a framework for travel at the speed of light. However, the thought experiment can still be modified and take on a moral dimension: Are more copies better than just one? How do we make sense of those individuals who believe that teletransportation is the new reproduction and construct a clone army of themselves? I’ll explore these questions in a later article.
So far, I lodged an argument asserting that identity truly is not what matters, because it does not bear up to duplication paradoxes. I want to now make sense of that statement, in a way that relates to our everday life, because I think the loss of identity as something that matters not depressing, but empowering. That warrants some some wild-eyed philosophizing. Here goes.
We are persons at three different levels. Each level subsumes us under an increasingly narrow group — conscious creatures, creative entities, psychological identities — and all three levels together provide the basis for personal identity.
We are conscious persons, entities who feel there is something like to be a person. This unifies us among all sentient creatures — humans, likely mammals and perhaps many other animals — distinguishing us from the non-sentient.
We are creative persons, entities who can creatively replicate and modify memes (culturally inherited behaviors). This encapsulates our ability to grokk new idea and ratiocinate about new situations for which our genes have no knowledge. Creativity is not shared by any of our cousins in the animal kingdom, or at least no manifest creativity. So, for now, it distinguishes humans into a class of themselves. However, in the future, humans will cohabitate the set of all creative persons with AGIs.
We are psychological persons, entities who relate with an individual in the past or future via a hodgepodge of overlapping links: links of memories and goals; desires and interests; character and personality quirks; even bodily features and social network. Just as a ship can retain the same identity to us after all its planks are gradually replaced, each psychological link can about-face with no change of person.
The conscious, creative and psychological layers are the only ones inherent to us; unlike identity, they are what matter. Yet there is an identity in our lives. It is only external to us. My identity is at bottom a social identity, a simplification I proffer to the world as a self-consistent narrative about who I am, how I act and what makes me me. It has societal and social import, because we can treat concrete identites as agents, persons with goals constrained by the law, and interpret their actions as responsible or criminal, felicitous or fatuous.
Identity is important. But it is only a manner through which we think about someone. I argued earlier that if there exist two versions of myself — my Martian copy and Earthly original — the identity of Adam, which the original harbored prior to the Martian copy, is destroyed, because the two had equal privilege to that identity, and identity can only have one possessor. What does it mean to say that the original’s identity is destroyed if nothing about him changed, only the causally independent event of the copying? It must mean that something external to him ceases to be, for nothing about him changed.
Now, if you will allow me some poetic license: Our personhood comprises a conscious experience, interpreted with the creation of interpretations and criticisms of those interpretations, accumulating into a tapestry of memories and quiver of knowledge that in turn brings us to direct ourselves by choice to particular experiences and particular explanations. Our unity involves a mobius strip of each layer giving way to the next in a creative conversation, with the elements, with our own ideas. Identities are useful, but they are too concrete to capture that dynamism, and too externally conceived to be a part of us that matters. After all, it is our mental models in our brains — our explanations — that create identities for things, not an aspect of the world itself. And, as I’ve argued here, identity is not our best explanation, for is a concept riddled with paradox. Our identity solidifies when relating to others, when we imagine ourselves as an object in the world for them, and yet, there is only a mutable process of patterns when pondering alone: alone, we live in our bodies as a question rather than a statement.
 This line is called the Psychological Criterion of Personal Identity, as formulated by Derek Parfit. (Personal Identity and Ethics)
 The reason why two people must be uniquely psychologically continuous to be the same person is because of a property of identity philosophers call the transitivity (yes, the same kind of transitivity in logic or proofs). The following is an demonstration of what transitivity means when applied to identity.
if `original_t1` = `original_t2` and `original_t1` = `copy_t1`, then `original_t2` must = `copy_t2`
The `original` is the same person at `t1` and `t2`, since nothing but a bit of time changed. However, the `original` at `t1` is also identical to the `copy` in everything that matters, they are the same. That must imply that `original` at `t2` identical to the `copy` at `t2`.
 An image created by a neural net optimized for trees. See Gabriel Goh et al. “Multimodal Neurons in Artificial Neural Networks.” (Distill Pub, 2021.)
 There is another way out developing (still philosophically crude though), and it escapes this dilemma by using a different criterion of identity, say, one the concerns causes instead of states. For instance, in the Singular Creative strategy, any copy is a new entity and any non-copied, non-vaporized person is identical to the original of prior times. So they define identity in terms of connectors: Causally connected instances have the same identity and a new identity is created if there is a “causal discontinuity”, whatever that means (they left its meaning vague). How does this map to the diagram above? `A` = `C` and `A` != `B`. For a full presentation of the Singular Creative Strategy, see Simon Langford & Murali Ramachandran (2013), “The Products of Fission, Fusion, and Teletransportation: an Occasional Identity Theorist’s Perspective.” Australasian Journal of Philosophy.
 Wording from Nagel, Thomas. “What is it like to be a bat?” …
 See the chapters on memes and creativity in Deutsch, David. The Beginning of Infinity. …
Also, Deutsch presents at essence the same idea about creative persons in that book, but he refers to them as merely persons.
 This is a reference to the Ship of Theseus, which was my first article in this Philosophy of Mind and Identity Series. See <article>.
 From a great poetry book: Whyte, David (2020). Consolations: The Solace, Nourishment and Underlying Meaning of Everyday Words. Many Rivers Press.
 Parfit, Derek (1987). Reasons and Persons. Oxford, Clarendon Press. The problem is also presented in Olson, Eric T., “Personal Identity”, The Stanford Encyclopedia of Philosophy (Spring 2021 Edition).
 The foundations of a universal constructor, basically a 3D printer that can build any physically possible object, are already being laid out. For the philosophy of it, see David Deutsch & Chiara Marletto (2015). “Constructor theory of information.” The Royal Society.
 This list includes most of the criteria for what matters in survival in the philosophy of identity as drawn from Shoemaker, David, “Personal Identity and Ethics”, The Stanford Encyclopedia of Philosophy (Winter 2019 Edition).
 I develop the approach of thinking of identity as mental models in the first article in the series, P&R I: Theseus’s New Planks and Our Mental Models
 This is a longer footnote that introduces various stances on consciousness and explains why the consciousness of my Martian ‘copy’ and me are identical, according to each stance.
To Physcialism, which asserts everything in the world is created from physical matter and energy, the consciousnesses are equal according because my ‘copy’ and I are made up of the same physical substances arranged in the same patterns, which is what gives rise to consciousness.
Panpsychism says the emergence of consciousness from non-conscious physical matter does not make sense, so it ascribes consciousness to matter. People are made up of conscious quarks and electrons, and those scintillae of consciousness build up when connected, giving rise to our consciousness. However, since my Martian ‘copy’ and I are built from (presumably conscious) quarks and electrons in identical manners, our consciousnesses should be equal.
As introduced in The Case Against Reality, conscious realism takes a similar stance to Panpsychism, taking consciousness to be fundamental, but defines the fundamental units of reality as conscious agents rather than ascribing consciousness to physical matter. In other words, physical matter emerges from conscious agents. What we see as quarks and electrons are icons hiding the conscious agents from which they emerged, which seems plausible because we did not evolve to see reality as it is, but only simplified features promoting survival (e.g. seeing only visible light rather than the whole spectrum). But whether physical matter is fundamental or just icons hiding the fundamental conscious agents, constructing physical matter in identical ways presumably yields identical configurations of conscious agents. Accordingly, the consciousness of my copy and me are identical.
If you maintain mind-body dualism and assert that people are endowed with magical ectoplasm when in their mother’s womb, however, the consciousness of my ‘copy’ and me need not be identical. Although I won’t launch into a tirade about dualism here, I don’t think this view is rationally tenable, though.
Also note that by this argument, i.e. a perfect physical replication must yield identical consciousness according to every currently tenable consciousness theory, I reject the existence of philosophical zombies.
 It is from that moment of information that our consciousness and everything that matters about ourselves arises, and this is true even if you subscribe to Panpsychist or any other wacky consciousness stance of your choosing (see footnote 3). The phrase was drawn from and idea inspired by Loh, Max. “Mind Uploading Would Actually Transfer Your Consciousness: Debunking the ‘One Me’ Fallacy.” Max Loh Blog, 2019.
 Substrate-independence means that the same information encoded in any material can be identically encoded in another substrate. All information has this property, the practical significance of which is that the information that is you and I can be encoded in silicon hardware equally well. For more, see Tegmark, Max. Life 3.0. 2017, Knopf Publishing Group.