All of Gadersd's Comments + Replies

All proofs at least implicitly contain the conclusion in the assumptions or axioms. That's because proofs don't generate information, they just unravel what one has already assumed by definition or axioms.

So yes, I'm implicitly assuming the conclusion in the assumptions. The point of the proof was to convince people who agreed with all the assumptions in the first place but who did not believe in the conclusion. There are people who do believe the assumptions but do not agree with the conclusion, which, as you say is in the assumptions.

"Indistinguishability" in my original argument was meant as a behavior change that reflects the subject's awareness of a change in consciousness. The replacement indistinguishability is not transitive. Regardless of how many are replaced in any order there cannot be a behavior change, even if it goes as A to B, A to C, A to D...

I think we differ in that I assumed that a change in consciousness can be manifested in a behavior change. You may disagree with this and claim that consciousness can change without the behavior being able to change.

I assume that's a typo for "is transitive". Why not? If you assume absolute identity of behaviour, you're assuming the conclusion. But absolute identity is unobservable. The best you can get is indistinguishability under whatever observations you're making, in which case it is not transitive. There is no way to make this argument work without assuming the conclusion.

"It feels strange to me, somewhat analogous to arguing that Bigfoot can't do magic while neglecting to mention that he also doesn't exist."

I assumed that the assumptions used would resonate with people. I used to believe in a rigid soul like concept of identity when I was a child, likely stemming from my religious upbringing. Thinking of an argument similar to what I wrote is what relaxed my once rigid view of identity.

"...I don't really care if my identity is preserved in this particular form. I just care about having positive experiences."

I think this is... (read more)

"There is an assumption here that your future self shares an identity with your current self that other people don't, which is called Closed Individualism."

I actually wrote the argument for people who believe in Closed Individualism. I myself subscribe to Open Individualism. The purpose was to convince people who subscribe to Closed Individualism to not reject cryonics on the basis that their identity will be lost. Some people, even if revived after cryonics, may worry that their identity has fundamentally changed which can lead to an existential crisis.

"I... (read more)

4Rafael Harth2y
That's interesting, both because I wouldn't expect an Open Individualist to be interested in cryonics, and because I wouldn't expect an OI to make this argument. Do you agree that you could prove much stronger claims about identity with equal validity? It feels strange to me, somewhat analogous to arguing that Bigfoot can't do magic while neglecting to mention that he also doesn't exist. But I'm not saying that arguing under an assumption you don't believe in isn't valuable. I enthusiastically agree with Eliezer Yudkowsky that the utilitarian argument against cryonics is weak under the assumption of Closed Individualism. Even committed EA's enjoy so many luxuries that there is no good reason why you can't pay for cryonics if that's what you value, especially if it helps you live with less fear (in which case it's an investment). However, if you're an open individualist, there is no reason to be afraid anyway, so I don't see why you would spend the ~200.000$ on cryonics when you can use it for higher priority causes instead. I don't have any moral qualms with it, I just don't see the motivation. I don't think I'm happy or smart enough for it to be worth it, and I don't really care if my identity is preserved in this particular form. I just care about having positive experiences. (I still approve of advertising cryonics for practical reasons. It may change the behavior of powerful people if they believe they have skin in the game.)

Let P(n) designate the proposition that the procedure does not alter current or future consciousness if n neurons are replaced at once.

  1. P(0) is true.

       2. Suppose P(k) is true for some number k. Then replacing k neurons does not change consciousness for the present or future. Replace a single extra neuron in a neglible amount of time since the former replacement, such as the reaction time of a single neuron divided by the total number of neurons in the brain. #Replacing a single neuron on an unaltered consciousness with a functional ... (read more)

Then that undercuts the whole argument. That is exactly the argument by the beard. It depends on indistinguishablility being a transitive property, but it is not. If A and B are, for example, two colours that you cannot tell apart, and also B and C, and also C and D, you may see a clear difference between A and D. You cannot see grass grow from one minute to the next. But you can see it grow from one day to the next.

Gödel established fundamental limits on a very specific notion of "knowing", a proof, that is, a sequence of statements that together justify a theorem to be true with absolute certainty.

If one relaxes the definition of knowing by removing the requirement of absolute certainty within a finite time, then one is not so restricted by Gödel's theorem. Theorems regarding nonfractional numbers such as what Gödel used can be known to be true or false in the limit by checking each number to check whether the theorem holds. 

Theorems of the nature "there exists... (read more)

Where did I say "times"? I meant that kN neurons are effectively replaced at once. I said in the argument that the neurons are replaced with a neglible time difference.

Doing them all at once doesn't help. You are still arguing that if kN neurons make no observable difference, then neither do (k+1)N, for any k. This is not true, and the underlying binary concept that it either does, or does not, make an observable difference does not fit the situation.

If plucking hairs changes my beard then there will be a point at which it is noticeable before it is completely gone. My beard does not go from existing to not existing in a single pluck.

My consciousness does not go from existing to not existing in a single neuron pluck. My identity does not radically change in a single pluck. There is a continuum of small changes that lead to large changes. There will come a point at which the changes accumulate that can be noticed.

Note that I'm not referring to gradual changes through time, but a single procedure occurri... (read more)

You refer to doing this k times. There is your gradual process, your argument by the beard. If A is indistinguishable from B, and B is indistinguishable from C, it does not follow that A is indistinguishable from C.
One advantage to a thought experiment is that it can be scaled without cost. Instead of your  sorites series, let us posit a huge number of conscious humans. We alter each human to correspond to a single step in your gradual change over time, so that we wind up performing in parallel what you posit as a series of steps. Line our subjects in "stage of alteration" order. Now the conclusion of your series of steps corresponds to the state of the last subject in our lineup. Is this subject's consciousness the same as at start? If we assume yes, then we have assumed our conclusion, and the argument assumes its conclusions. If we assume for sake of argument the subject's consciousness at the end of our lineup differs from the start of the lineup, then we can walk along the line and locate where we first begin to notice a change. This might vary with groups of subjects, but we can certainly then find a mean for where the change may start. This is possible even if in series we cannot perceive a difference between the subject from one step to another.

How do you know there are things you cannot know eventually?

Gödel. And no the halting problem is separate from Gödels arguments.

The philosophical problems people have with identity may seem silly, but many people are affected by it. Some people who may otherwise have no problems with cryonics or other preservation techniques will choose guaranteed death because they don't intuitively think their consciousness will persist. That is why I think it is so significant. People who doubt for practical reasons can be convinced in time if the technology comes up to speed, but those who deny it for philosophical reasons may never be convinced regardless of technological advancements.

An easy ... (read more)

4Stuart Anderson2y

>Heisenberg's uncertainty principle clearly demostrates that there are claims about the physical world that we can't evaluate as through or false through observation and science.

What you are saying implies, for example, that a particle's momentum has a precise value but cannot be known by observation if the particle's position is known with certainty. How do know this? It could just as well be that the particle's position and momentum are mutually exclusive to a degree such that if the position is known with high certainty, then the momentum does not ha... (read more)

There are things we don't know. There are questions where we don't know the answer. Both saying "I know that identity survives cryonics" and saying "I know that identity survives cryonics" require justification. The position of not knowing doesn't. 

If I continually pluck hairs from my beard then I have noticeably less of a beard. Eventually I will have no beard. Replacing some neurons with the given procedure does not change behavior so the subject cannot notice a change. If the subject noticed a change then there would be a change in behavior. If you assert that a change in consciousness occurred, then you assert that a change in consciousness does not produce a change in consciousness to notice it.

We can fall asleep without noticing, but there is always a way to notice the changes. One can decide t... (read more)

Almost all gradual-brain-to-device replacement arguments are indeed sorites arguments. You assume: Plucking one or three hairs from a beard that has 10000 hairs beard is too small an action to change a beard visibly Plucking 2 hairs from a beard with 9998 hairs is too small a change to see (true) Plucking 2 hairs from a beard with 9996 hairs is too small a change to see (true) ... plucking 2 hairs 4000 times from a beard is too small a change to see (false)

Ok, #5 was a bit strong for this, though I must argue that Heisenberg's uncertainty principle itself was discovered through observation. Using a claim justified by observation and experiment to undermine the sufficiency of observation with regards to evaluating claims in general seems off to me.

If a change or thing has no observable effects, how can one claim that that change or thing exists? Eliezer himself believes that the Many-Worlds Hypothesis has observable effects, namely anthropic immortality, which can be tested if one is willing.

Bayesian updating... (read more)

Proof by contradition is a standard way to make proofs in mathematics.  The fact that there are truths that one can't verify, means that there are things one doesn't know (and Gödel showed that on a very fundamental level). Being skeptic and not believing things without evidence means that there are things that one doesn't know and can't know.