Is the “Old Me” Destroyed When I Teleport From Mars?

I am stranded on Mars. The fuel tanks on my return vessel ruptured, and no rescue team can possibly reach me before I run out of food. (And, unlike Matt Damon, I have no potatoes.) Luckily, my ship features a teleporter. It is an advanced bit of gadgetry, to be sure, but the underlying idea is simplicity itself: the machine scans my body and produces an amazingly detailed blueprint, a clear picture of each cell and neuron. That blueprint file is then beamed back to Earth, where a ‘new me’ is constructed using raw materials available at the destination site. All I have to do is step in, close my eyes, and press the red button…..

But there’s a complication: a toggle switch allows me to decide whether the ‘old me’ on Mars is preserved or destroyed after I teleport back home. It’s this decision that is causing me to hesitate.

On the one hand, it seems like what makes me me is the particular way in which all my components fit together. I don’t think there is such a thing as a soul, or some ghost that inhabits my machine. I’m just the result of the activity among my 100 billion neurons and their 100 trillion distinctive connections. And, what’s more, that activity is what it is, no matter what collection of neurons is doing it. If you went about replacing those neurons one by one, but kept all the connections and activity the same, I would still be me.

So, replacing them altogether at once should not matter, so long as the distinctive patterns are maintained. This leads me to want to press the button and get back to my loved ones – and back to Earth’s abundant food, water and oxygen, which will allow me to continue repairing and replacing my cells in the slower, old-fashioned way.

So: if I put the toggle in the ‘destroy’ setting, I should survive the transfer just fine. What would be lost? Nothing that plays any role in making me me, in making my consciousness my own. I should step in, press the button – and then walk out of the receiver back on Earth.

“Maybe the notion that I am an enduring self over time is some sort of stubborn illusion.”

On the other hand, what happens if I put the toggle in the ‘save’ setting? Then where would I be? Would I make the trip back to Earth, and then feel sorry for the poor sap back on Mars (the old me), who will be facing slow death by starvation? Or – horrors! – will I be that old me, feeling envy for the new me who is now on Earth, enjoying the company of friends and family?

Could I somehow be both? What would that be like? Would I be seeing the scene on Earth superimposed upon the Martian landscape? Would I be feeling both pangs of hunger and exquisite delight in eating my first home-cooked meal in years? How would I decide at the same time to both walk over the dunes of red sand and go to sleep in my own bed? Is this even conceivable?

Perhaps I need to adopt a more objective point of view. Suppose others were observing all this. What would they see? They would see me step in, press the button, and then – depending on the toggle setting – they would see either two copies of me, one on Mars and one on Earth, or else just one copy of me on Earth and some smouldering remains on Mars. There is no real problem, from this outsider’s point of view. There is no test an observer could perform to determine whether I survived the trip to Earth – no personality test, no special ‘me-ometer’ readings, no careful analysis of discrepancies among the neurons. Everything proceeds as expected, no matter what the toggle setting is.

Maybe there is something to be learned from this. Perhaps what seems to me an extremely obvious truth – namely, that there should be some fact to the matter of what I experience once I step in and press the button – is really not a truth at all. Maybe the notion that I am an enduring self over time is some sort of stubborn illusion.

A very similar sort of question was raised in 1775 by the Scottish philosopher Thomas Reid, in a letter to Lord Kames referencing Joseph Priestley’s materialism: ‘whether when my brain has lost its original structure, and when some hundred years after the same materials are again fabricated so curiously as to become an intelligent being, whether, I say, that being will be me; or, if two or three such beings should be formed out of my brain, whether they will all be me’.

This story was written by Charlie Huenemann. He is professor of philosophy at Utah State University and author of several books and essays, and reprinted materials from Pionic. Materials may be edited for content and length.

Image: SpaceX