They don't. 99.5% is far too much.

Ok -- thanks for a detailed response. To be honest, I think you are quibbling. If your posterior is 99.5% and 95% if being pessimistic you made up your mind essentially as far as a mind can be made up in practice. If the answer to the upload question depends on an empirical test that has not yet been done (because of lack of tech), then you made up your mind too soon.

Of course, the real reason that we don't talk too much about what happens if uploading isn't possible is that that would just make the future that much more like the present.

I think a cynic would say you talk about the upload future more because its much nicer (e.g. you can conquer death!)

Ok, what exactly is your posterior belief that uploads are possible? What would you say the average LW posterior belief of same? Where did this number come from? How much 'cognitive effort' is spent at LW thinking about the future where uploads are possible vs the future where uploads are not possible?

Either this is self-contradictory, or it means 'never be wrong'.

I think if you are making up your mind on unsettled empirical questions, you are a bad Bayesian. You can certainly make decisions under uncertainty, but you shouldn't make up your mind. And anyways, I am not even sure how to assign priors for the upload fidelity questions.

I was trying to position the paper in terms of LW opinions

Why?

LW consensus is not necessarily wrong, even if Scott is right. However, making up your mind on unsettled empirical questions (which is what LW had done if Scott is right) is a dangerous practice.

I found the phrasing "he then moves in a direction that's very far from any kind of LW consensus" broadly similar to "he's not accepting the Nicene Creed, good points though he may make." Is there even a non-iffy reason to say this about an academic paper?

Do I understand it correctly that the question is, essentially, whether there exists a more efficient way of modelling the brain than modelling all particles of the brain?

I don't presume to speak for Scott, but my interpretation is that it's not a question of efficiency but fidelity (that is, it may well happen that classical sims of brains are closely related to the brain/person scanned but aren't the same person, or may indeed not be a person of any sort at all. Quantum sims are impossible due to no-cloning).

For more detailed questions I am afraid you will have to read the paper.

Absolutely, here's the relevant quote:

"The question also has an “empirical core” that could turn out one way or another, depending on details of the brain’s physical organization that are not yet known. In particular, does the brain possess what one could call a clean digital abstraction layer: that is, a set of macroscopic degrees of freedom that

(1) encode everything relevant to memory and cognition,

(2) can be accurately modeled as performing a classical digital computation, and

(3) “notice” the microscopic, quantum-mechanical degrees of freedom at most as pure randomnumber sources, generating noise according to prescribed probability distributions?"

You could do worse things with your time than read the whole thing, in my opinion.

I think he proposes an empirical question the answer to which influences whether e.g. uploading is possible. Do you think his question has already answered? Do you have links explaining this, if so?

But that's just a starting point, and he then moves in a direction that's very far from any kind of LW consensus.

If he says:

"In this essay I’ll argue strongly for a different perspective: that we can easily imagine worlds consistent with quantum mechanics (and all other known physics and biology) where the answer to the question [scanning of minds possible?] is yes, and other such worlds where the answer is no."

and he's right, then LW consensus is religion (in other words, you made up your mind too early).