Many thinkers believe that we will eventually be able to preserve our consciousness indefinitely. There are a number of scenarios by which this might be accomplished but so-called mind uploading is one of the most prominent.
Mind uploading refers to a hypothetical process of copying the contents of consciousness from a brain to a computational device. This could be done by copying and transferring the entire contents into a computer or by piecemeal replacement with parts of the brain gradually replaced by hardware. Either way, consciousness would no longer be running on a biological brain.
I am in no position to judge the feasibility of mind uploading; experts have both praised and pilloried its viability. Nor can I judge what it would be like to live in a virtual reality—I don’t even know what it’s like to be another person. In fact, we don’t exactly know exactly;u how the brain gives rise to subjective experiences, so we certainly don’t know what it would be like to exist as a simulated mind inside a virtual reality or a robotic body.
But does it make sense to think a mind program could run on something other than a brain? Isn’t our subjective consciousness rooted in the biological brain? Yes, for now, our mental software runs on the brain’s hardware. But there is no necessary reason that this must be the case. If I told you a hundred years ago that some integrated silicon circuits will soon play chess better than grandmasters, model future climate change, recognize faces and voices, solve famous mathematical problems, and write poetry, you would be astonished. Today you might reply, “but computers still can’t feel emotions or taste a strawberry.” And you are right they can’t—for now. But what about a thousand years from now? What about ten thousand or a million years from now? Do you really think that in a million years the best minds will run on carbon-based brains?
If you still find it astounding that minds could run on silicon chips, consider how remarkable it is that our minds run on meat! Imagine beings from another planet with cybernetic brains discovering that humans have meat brains. These aliens have encountered many sentient beings in their travels but never ones like us. That we are conscious and communicate by means of such brains would amaze them. They might find this as implausible as we do the idea that minds could run on silicon or some other substrate.
To understand how mental software could run on non-biological hardware, think of mental states not in terms of their physical implementation but in terms of their functions. For instance, one of the functions of the pancreas is to produce insulin which maintains the balance of sugar and salt in the body. It is easy to see that something else could perform this function, say a mechanical pancreas. Now consider an hourglass or an atomic clock. The function of both is to keep time yet they do this quite differently.
Analogously, if mental states are identified by their functional role then they too could be realized on other substrates, as long as the system performs the appropriate functions. Once you have jettisoned the idea that your mind is a ghostly soul or some other mysterious, impenetrable, non-physical substance, it is relatively easy to see that your mind program could run on something besides a biological brain. Now there’s no way for us to know what it would be like to exist without a brain and body, but there’s no convincing reason to think that one couldn’t have subjective experiences without physicality. Perhaps our experiences would be even richer without a brain and body.
We have so far ignored important philosophical questions about whether a consciousness transferred to a computer is you or just a copy of you. However, I doubt that such existential worries will stop people from using technology to preserve their consciousness when oblivion is the alternative. We are changing every moment and few worry that we are only a copy of ourselves from ten years ago. We wake up every day as a copy of what we were yesterday and few fret about that.
We might also ask what one does inside a simulated reality for an indefinitely long time. The Princeton neuroscientist Michael Graziano agrees that the question is not whether we will be able to upload our consciousness into a computer—he says we will—but what we will do afterward. He suggests we may get bored.
I suppose that some may get bored with being conscious for eons of time and prefer annihilation instead. Some would get bored with the heaven they supposedly desire. Some are bored now. So who wants to extend their consciousness so that they can love better and know more? Who wants to live long enough to have experiences that surpass our current ones in unimaginable ways? The answer is … many of us do. Some of us aren’t bored easily. And if we get bored we should make sure that we can always delete the program.