Let me try coming at this another way. What would you not expect in a Turing-implementable Universe?
Life
Life that perceives, eg, threats (ie has organs adapted to be sensitive to things like light, and reacts adaptively when these organs get signals correlated with the presence of a threat)
Life that perceives threats and reacts to them in such a way that other closely related living things react to their reaction as if the threat was there (ie, some form of communication)
Life whose later actions are adaptively changed by earlier perceptions (in the sense of perceptions above), ie memory
Life that communicates the perceptions it remembers
Life whose communication has grammar, so it can say things like “I saw a tiger yesterday” or “I saw a red thing”
Life that asks what is red about red
something else?
EDIT NB: I’m asking what you see that you would not expect to see if you were looking into a Turing-universe from the outside. If your position is that there’s nothing in this Universe visible to an external observer that shows it to be non-Turing, including our utterances, please make that explicit.
Turing computability is not much of an issue for me. It amounts to asking whether the state transitions in an entity can be abstractly mimicked by the state transitions in a Turing machine. For everything in your list, the answer ought to be, yes it can.
However, that is a very limited and abstract resemblance. You could represent the mood of a person, changing across time, with a binary string. But to say that their sequence of moods is a binary string is descriptive rather than definitional.
It sounds like you do want to reduce all mental or conscious phenomena to strictly computational properties. Not just to say that the mind has certain computational properties, but that it has nothing but such properties; that the very definition of a mind is the possession of certain computational properties or capacities.
To do this, first you will need to provide an objective criterion for the attribution of computational properties, such as states. You can chop up a physical state space in many ways, so as to define “high-level” states; which such clustering of physical states, out of all the possibilities, is the one that you will use, and why? Then, you may need to explain what is computational about these states. If you want to say that they have representational content, for example, you will need to say what they are representing and on what basis you attribute this meaning to them. And finally, if you also wish to say that sensory qualities like colors are nothing but computational properties, you will need to say which computational properties, and something about why they “feel” that way.
All of this assumes that you agree that color and meaning do exist in experience. If they are there, they need to be explained. If they do not need to be explained, it can only be because they are not there.
So your position is that there’s no problem accounting for everything we observe in human behaviour, including behaviour like saying “where does subjective experience come from?”, with a physics much like standard physics; but to account for the actual subjective experience itself we need a new physics? That current physics leaves us with a world of what I term M-zombies, who talk about subjective experience but don’t have any?
You seem to have given exactly the reply that my “EDIT NB”, added before your reply, was designed to forestall.
Can you state that in terms of what you would see looking in from the outside? For example, do you think you would not see life that used phrases such as “the subjective experience of the colour blue”?
I meant I did agree with you, and that externally everything would appear exactly the same. However, from what I think is Mitchell Porter’s point of view, the one thing you would not expect from such a universe is the possibility of being inside it. P-Zombies, I suppose.
Ah, OK! I don’t know whether anyone’s going to try to mount a zombie-based defence of Porter’s position. These are the articles it would need to reply to. M-zombies would be distinct from P-zombies in that Porter believes that physics can account for our non-zombieness, but M-zombies would still write articles asking where subjective experience comes from, even though they don’t have any.
EDIT: commenters below have caused me to think better of my impatient tone below. Please imagine strikethrough through
In the absence of any replies[*] from you more than 24 hours after you posted the original article, which I think is a little rude and I hope is accounted for by unexpected real-world constraints, I shall resort to further attempts to anticipate and forestall possible replies.
“I don’t know” isn’t an acceptable answer either. The question isn’t “what will happen in such a Universe”, it’s “at what point to you balk at the possibility”. You balk before the end of “it could be just like our Universe” and after the beginning (which is, say, the game of Life) so you have to be able to identify a balk point somewhere on the scale.
EDIT: would appreciate downvote explanation—thanks!
EDIT: [*] to any comments in this thread, not just to my comments—thanks Alicorn for prompting me to clarify
This is an asynchronous medium, and Mitchell_Porter is not obliged to address your inquiry anyway. It’s possible he hasn’t even seen your comment. Perhaps you could send him a PM, which would be harder for him to miss, and ask him if he’d have a look at your question without accusing him of being rude for not having done so already.
Edit: This comment also serves as your downvote explanation.
Not my enquiry specifically—he’s made no comments at all since posting the article. I think that if you make a top level post you do have an obligation to take part in the subsequent discussion.
If I’d written a post that’d gotten downvoted into the negative that decisively, I’d take a day or two off to avoid posting extremely defensive comments. I have no idea if that’s what Mitchell is doing, but while he probably should make some attempt to field comments on his post, chiding him for being untimely is not nice.
From the votes, it looks like people agree with you rather than me on this, which I take seriously. If anyone else wants to downvote me on this one, I’d slightly prefer they downvote the grandparent comment rather than my one above that, so I know it’s the chiding rather than the argument that’s getting downvoted.
Needling your interlocutor for a prompt reply makes it sound as you’re more interested in “winning the debate” than in getting a considered reply from them. If it takes someone a couple days to let the dust settle, consider possible counter-arguments or lines of retreat, and frame a careful reply, don’t begrudge them that.
I’d like to think about this more, but what you say sounds convincing just now. I’ve been ill this week, which is why I’ve been online so much, which may be affecting my judgement.
If it makes you feel any better, in the last discussion, several posters referenced my explanation, which you would think would bump me up on his reply priority list. It didn’t.
While I’m hoping for my comments to receive a reply, I’m looking forward to all his replies. We enjoy such a high standard of debate here that it makes me impatient for more.
Let me try coming at this another way. What would you not expect in a Turing-implementable Universe?
Life
Life that perceives, eg, threats (ie has organs adapted to be sensitive to things like light, and reacts adaptively when these organs get signals correlated with the presence of a threat)
Life that perceives threats and reacts to them in such a way that other closely related living things react to their reaction as if the threat was there (ie, some form of communication)
Life whose later actions are adaptively changed by earlier perceptions (in the sense of perceptions above), ie memory
Life that communicates the perceptions it remembers
Life whose communication has grammar, so it can say things like “I saw a tiger yesterday” or “I saw a red thing”
Life that asks what is red about red
something else?
EDIT NB: I’m asking what you see that you would not expect to see if you were looking into a Turing-universe from the outside. If your position is that there’s nothing in this Universe visible to an external observer that shows it to be non-Turing, including our utterances, please make that explicit.
By life I assume you mean replicators.
Turing computability is not much of an issue for me. It amounts to asking whether the state transitions in an entity can be abstractly mimicked by the state transitions in a Turing machine. For everything in your list, the answer ought to be, yes it can.
However, that is a very limited and abstract resemblance. You could represent the mood of a person, changing across time, with a binary string. But to say that their sequence of moods is a binary string is descriptive rather than definitional.
It sounds like you do want to reduce all mental or conscious phenomena to strictly computational properties. Not just to say that the mind has certain computational properties, but that it has nothing but such properties; that the very definition of a mind is the possession of certain computational properties or capacities.
To do this, first you will need to provide an objective criterion for the attribution of computational properties, such as states. You can chop up a physical state space in many ways, so as to define “high-level” states; which such clustering of physical states, out of all the possibilities, is the one that you will use, and why? Then, you may need to explain what is computational about these states. If you want to say that they have representational content, for example, you will need to say what they are representing and on what basis you attribute this meaning to them. And finally, if you also wish to say that sensory qualities like colors are nothing but computational properties, you will need to say which computational properties, and something about why they “feel” that way.
All of this assumes that you agree that color and meaning do exist in experience. If they are there, they need to be explained. If they do not need to be explained, it can only be because they are not there.
So your position is that there’s no problem accounting for everything we observe in human behaviour, including behaviour like saying “where does subjective experience come from?”, with a physics much like standard physics; but to account for the actual subjective experience itself we need a new physics? That current physics leaves us with a world of what I term M-zombies, who talk about subjective experience but don’t have any?
I imagine you would expect all those; one would simply not expect the subjective experience of the colour blue.
You seem to have given exactly the reply that my “EDIT NB”, added before your reply, was designed to forestall.
Can you state that in terms of what you would see looking in from the outside? For example, do you think you would not see life that used phrases such as “the subjective experience of the colour blue”?
I meant I did agree with you, and that externally everything would appear exactly the same. However, from what I think is Mitchell Porter’s point of view, the one thing you would not expect from such a universe is the possibility of being inside it. P-Zombies, I suppose.
EDIT: Also, sorry for not being clear re your NB.
Ah, OK! I don’t know whether anyone’s going to try to mount a zombie-based defence of Porter’s position. These are the articles it would need to reply to. M-zombies would be distinct from P-zombies in that Porter believes that physics can account for our non-zombieness, but M-zombies would still write articles asking where subjective experience comes from, even though they don’t have any.
EDIT: commenters below have caused me to think better of my impatient tone below. Please imagine strikethrough through
“I don’t know” isn’t an acceptable answer either. The question isn’t “what will happen in such a Universe”, it’s “at what point to you balk at the possibility”. You balk before the end of “it could be just like our Universe” and after the beginning (which is, say, the game of Life) so you have to be able to identify a balk point somewhere on the scale.
EDIT: would appreciate downvote explanation—thanks! EDIT: [*] to any comments in this thread, not just to my comments—thanks Alicorn for prompting me to clarify
This is an asynchronous medium, and Mitchell_Porter is not obliged to address your inquiry anyway. It’s possible he hasn’t even seen your comment. Perhaps you could send him a PM, which would be harder for him to miss, and ask him if he’d have a look at your question without accusing him of being rude for not having done so already.
Edit: This comment also serves as your downvote explanation.
Thanks, it’s good of you to explain.
Not my enquiry specifically—he’s made no comments at all since posting the article. I think that if you make a top level post you do have an obligation to take part in the subsequent discussion.
If I’d written a post that’d gotten downvoted into the negative that decisively, I’d take a day or two off to avoid posting extremely defensive comments. I have no idea if that’s what Mitchell is doing, but while he probably should make some attempt to field comments on his post, chiding him for being untimely is not nice.
From the votes, it looks like people agree with you rather than me on this, which I take seriously. If anyone else wants to downvote me on this one, I’d slightly prefer they downvote the grandparent comment rather than my one above that, so I know it’s the chiding rather than the argument that’s getting downvoted.
Needling your interlocutor for a prompt reply makes it sound as you’re more interested in “winning the debate” than in getting a considered reply from them. If it takes someone a couple days to let the dust settle, consider possible counter-arguments or lines of retreat, and frame a careful reply, don’t begrudge them that.
I’d like to think about this more, but what you say sounds convincing just now. I’ve been ill this week, which is why I’ve been online so much, which may be affecting my judgement.
If it makes you feel any better, in the last discussion, several posters referenced my explanation, which you would think would bump me up on his reply priority list. It didn’t.
While I’m hoping for my comments to receive a reply, I’m looking forward to all his replies. We enjoy such a high standard of debate here that it makes me impatient for more.