Suppose we discovered a gigantic truth-table in space such that we could point a telescope at some part of it and discover the result of S(x,t) where x is the initial state of a brain and t is the amount of time S simulates the brain being tortured. Is John Smith tortured if we point the telescope at the location where S(John Smith, 10 minutes) is found? Now suppose that instead there are several truth tables, one for each major region of John Smith's brain and having enough inputs and outputs such that we can look up the results of torturing parts of John Smith's brain and match them together at appropriately small intervals to give us the same output as S(x,t). Is John Smith tortured by using this method? What about truth tables for neuron groups or a truth table for a sufficiently generic individual neuron? How about a truth table that gives us the four results of AND NOT for two boolean variables, and we have to interpret S as a logical circuit to look up the results using many, many iterations?
Is John Smith tortured just by the existence of a particular level of truth table (perhaps the one for S(x,t) ) if no one computed it? If so, does it matter if someone re-computes that truth table since John Smith is tortured by it anyway? If John Smith would only be tortured by computing the tables then suppose P=NP and we can somehow calculate the truth tables directly without all the intermediate calculations. Would that torture John Smith or does the act of each individual computation contribute to the experience?
For the largest truth table that causes the lookup procedure to torture John Smith, does it matter how many times the lookup is done? For instance, if looking at S(John Smith,t) tortures John Smith, does it matter how many times we look or does John Smith experience each of the S(John Smith,t) only once? The smallest truth table that allows torture-free lookups corresponds to the post's C - E options of doing unlimited lookups without increasing torture.
Is there a level of truth tables that doesn't torture John Smith and won't cause his torture if someone looks up the results of S(x,t) using those tables? This seems the most unlikely, but perhaps there is a way to compute truth tables where a generic person is tortured which still returns accurate S(x,t) without torturing John Smith.
I don't have good answers to all those questions but I think that "doing computation = torture" is too simple an answer. I am on the fence about mathematical realism and that has a large impact on what the truth tables would mean. If mathematical realism is true then the truth tables already exist and correspond to real experience. If it's false then it's just a convenient thought experiment to determine where, how, and when (and how often) experience actually occurs: If truth tables at the whole brain or large brain region level constitute torture then I would assume that the experience happens once when (or if) the tables are generated and that multiple lookups probably don't cause further experience. Once neural groups or neuron lookups are being used to run a simulation I think some experience probably exists each time. By the time everything is computed I think it's almost certainly causing experience during each simulation. But suppose we find the mechanism of conscious awareness and it's possible to figure out what a conscious person feels while being tortured using truth tables for conscious thoughts and a full simulation of the rest of their brain. Is that as bad as physically torturing them? I don't think so, but it would probably still be morally wrong.
If you've read Nick Bostrom's paper on Unification vs. Duplication I think I find myself somewhere in the middle; using truth tables to find the result of a simulation seems a lot like Unification while direct computation fits with Duplication.
For my own part, I'm pretty confident labeling as "torturing John Smith" any process that computes all and only the states of John Smith's brain during torture, regardless of how those states are represented and stored, and regardless of how the computation is performed.
More generally (since I have no idea why we're using torture in this example and I find it distasteful to keep doing so) I'm pretty confident saying that any process that computes all and only the states of John Smith's brain during some experience X involves John experiencing X, ...
I've been thinking about ethics and brain emulations for a while and now have realized I am confused. Here are five scenarios. I am pretty sure the first is morally problematic, and pretty sure the last is completely innocuous. But I can't find a clean way to partition the intermediate cases.
A) We grab John Smith off the street, scan his brain, torture him, and then by some means, restore him to a mental and physical state as though the torture never happened.
B) We scan John Smith's brain, and then run a detailed simulation of the brain being tortured for ten seconds, and over again. If we attached appropriate hardware to the appropriate simulated neurons, we would hear the simulation screaming.
C) We store, on disk, each timestep of the simulation in scenario B. Then we sequentially load each timestep into memory, and overwrite it.
D) The same as C, except that each timestep is encrypted with a secure symmetric cipher, say, AES. The key used for encryption has been lost. (Edit: The key length is much smaller than the size of the stored state and there's only one possible valid decryption.)
E) The same as D, except we have encrypted each timestep with a one time pad.
I take for granted that scenario A is bad: one oughtn't be inflicting pain, even if there's no permanent record or consequence of the pain. And I can't think of any moral reason to distinguish a supercomputer simulation of a brain from the traditional implementation made of neurons and synapses. So that says that B should be equally immoral.
Scenario C is just B with an implementation tweak -- instead of _calculating_ each subsequent step, we're just playing it back from storage. The simulated brain has the same sequence of states as in B and the same outputs.
Scenario D is just C with a different data format.
Scenario E is just D with a different encryption.
Now here I am confused. Scenario E is just repeatedly writing random bytes to memory. This cannot possibly have any moral significance! D and E are indistinguishable to any practical algorithm. (By definition, secure encryption produces bytes that "look random" to any adversary that doesn't know the key).
Either torture in case A is actually not immoral or two of these adjacent scenarios are morally distinct. But none of those options seem appealing. I don't see a simple clean way to resolve the paradox here. Thoughts?
As an aside: Scenarios C,D and E aren't so far beyond current technology as you might expect. Wikipedia tells me that the brain has ~120 trillion synapses. Most of the storage cost will be the per-timestep data, not the underlying topology. If we need one byte per synapse per timestep, that's 120TB/timestep. If we have a timestep every millisecond, that's 120 PB/second. That's a lot of data, but it's not unthinkably beyond what's commercially available today, So this isn't a Chinese-Room case where the premise can't possibly be realized, physically.