In this post, I try to fathom an informal definition of “Self”, the essential qualities that make us unique.
DATA LOSS
Most humans don’t want to die, but what does that mean? What is it that humans try to preserve when they sign up for Cryonics? It seems that an explanation must account for and allow for some sort of data loss.
THE CONTINUITY OF CONSCIOUSNESS
The answer cannot involve the continuity of consciousness as we would have to refuse general anesthesia due to the risk of “dying.” But most of us will agree that there is something more important than the continuity of consciousness that makes us accept general anesthesia when necessary.
COMPUTATION
If the continuity of consciousness isn’t the most important detail about the self then it very likely isn’t the continuity of computation either.
To see this, suppose we were to come up with an algorithmic description of the human machine, of ourselves.
Now imagine that, for some reason, the process evoked when “we” act on our inputs under the control of this algorithm halts for a second and then continues otherwise unaffected, would we not mind being alive ever after because we died when the computation halted? This doesn’t seem to be the case.
But might it be this algorithm that we care about?
STATIC ALGORITHMIC DESCRIPTIONS
If we were to digitize our self we would end up with a description of our spatial parts, our self at a certain time. Yet we forget that all of us already possess such an algorithmic description of our selves and we’re already able back it up. It is our DNA.
TEMPORAL PARTS
Admittedly our DNA is the earliest version of our selves. Yet, if we don’t care about the temporal parts of our selves but only about a static algorithmic description of a certain spatiotemporal position, then what’s wrong with that? It seems a lot! We stop caring about past reifications of our selves. At some point our backups become obsolete and having to fall back on them would equal death. But what is it that we lost, what information is it that we value more than all of the previously mentioned possibilities? One might think that it must be our memories, the data that represents what we learned and experienced. But even if this is the case, would it be a reasonable choice?
If we had a perfect memory and only ever improved upon our past knowledge and experiences we wouldn’t be able to do so for very long, at least not given our human body. The upper limit on the information that can be contained within a human body is approximately 2.5072178×10^38 megabytes if it was used as a perfect data storage. Given that we gather much more than 1 megabyte of information per year, it is foreseeable that if we equate our memories with our self we’ll die long before the heat death of the universe. We might overcome this by growing in size, by achieving a posthuman form, yet if we in turn also become much smarter we’ll also produce and gather more information. We are not alone either and the resources are limited. One way or the other we’ll die rather quickly.
Does this mean we shouldn’t even bother about the far future or is there maybe something else we value even more than our memories? After all, we don’t really mind much if we forget what we have done a few years ago.
TIME-CONSISTENCY AND SELF-REFERENCE
It seems that there is something even more important than our causal history. I think that more than everything we care about our values and goals. Indeed, we value the preservation of our values.
For example, if a theist becomes an atheist, an atheist becomes a theist, a liberal becomes a conservative, or a conservative becomes a liberal, what has happened is that there are two versions of yourself at different points in time that are working against each other. From a rational perspective, this inability to keep our goals time consistent and to prevent our values from drifting can be *worse* than death. We became our own enemy.
As long as we want the same we are the same. Our goal system seems to be the critical part of our implicit definition of self, that which we want to protect and preserve. Our values and goals seem to be the missing temporal parts that allow us to consistently refer to ourselves, to identify our selves at different spatiotemporal positions.
Using our values and goals as identifiers also resolves the problem of how we should treat copies of ourselves that are featuring alternating histories and memories, copies with different causal histories. Any agent that does feature a copy of our utility function ought to be incorporated into our decisions as an instance, as a reification of our selves. We should identify with our utility function regardless of its instantiation.
STABLE UTILITY-FUNCTIONS
To recapitulate, we can value our memories, the continuity of experience, and even our DNA, but the only reliable marker for the self-identity of goal-oriented agents seems to be a stable utility function. Rational agents with an identical utility function will to some extent converge to exhibit similar behavior and are therefore able to cooperate. We can more consistently identify with our values and goals than with our past and future memories, digitized backups, or causal history.
But even if this is true there is one problem, humans might not exhibit goal stability.
What's especially perfidious about this is that it doesn't feel like turning into your own enemy. From the perspective of your future self or your descendants, it can feel like a rational update or simply natural. But goals and values are neither rational nor irrational. Goals and values cannot be wrong. Rationality is concerned with achieving goals, satisfying values, and obtaining accurate beliefs about the world. But if you do not have stable goals, or if you learn something about the world that completely undermines your goals, then all your efforts might have been worse than futile, they might have been actively harmful to your new goals.
Enjoyed this!
I think there's something missing though—I'm not seeing discussion of intergenerational inputs/outputs here. The way my family unit contextualizes identity is to see it as more of an unbroken chain of evolving utility functions, meme sets, and DNA. Each person is just one small link in a long chain preceded by ancestors that either terminates with them or extends onward through their offspring.
We don't worry so much about utility functions shifting because it would seem optimal for the chain to adapt in response to evolutionary pressures (and if anything, only one overarching utility function reigns supreme: reproduce or perish—people who don't produce offspring won't see their "identity" as we see it carried into the future, meaning their utility function is less likely to be represented in future populations).
This is just one view, though. There are plenty of groups that contextualize identity not at the family chain level, like I do, but rather on a tribal/cultural/national level.
As your essay highlights, the more we try to find out what we are, the more obvious it becomes that criteria limited to a single person's physical body—DNA, mind, present utility function, or memes—cannot be nailed down to a consistent, persistent thing, so why limit identity to any "single person" (who is constantly changing anyway)?
To me, at least, family lines seem like a more cohesive, predictable identity unit (consistent over time, connected in a concrete way that can be proven, multifaceted but constrained, iterative on multiple dimensions, and featuring at least one VERY consistent—at least in terms of "who survives" and gets a seat at the table in the future—utility function).