Qualia are physical phenomena. I dearly wish that this statement were uncontroversial. However, if you don’t agree with it, then you can reject the simulation argument on far simpler grounds: if experiencing qualia requires a “nonphysical” “soul” or whatnot (I don’t know how to make sense out of either of those words), then there is no reason to suppose that any man-made simulator is imbued with a soul and therefore no reason to suppose that it would be conscious. However, provided that you agree that qualia are physical phenomena, then to suppose that they are any kind of exception to the principle I’ve just stated is simply bizarre magical thinking. A simulator which reasons perfectly about a human being, even including correctly determining what qualia a human would experience, does not necessarily experience those qualia, any more than a simulator that reasons perfectly about high gravity necessarily produces high gravity.
Let’s replace qualia with some other phenomenon closely associated with the mind but less confusing. How about this: a poem. A really good poem, the sort of poem that we have not seen from anyone but the greatest human poets working at the peak of their art. So, let’s rewrite the above but replacing qualia with really good poems.
Really good poems are physical phenomena. I dearly wish that this statement were uncontroversial. However, if you don’t agree with it, then you can reject the simulation argument on far simpler grounds: if a really good poem requires a “nonphysical” “soul” or whatnot (I don’t know how to make sense out of either of those words), then there is no reason to suppose that any man-made simulator is imbued with a soul and therefore no reason to suppose that really good poems could arise therein. However, provided that you agree that really good poems are physical phenomena, then to suppose that they are any kind of exception to the principle I’ve just stated is simply bizarre magical thinking. A simulator which reasons perfectly about really good poems, even including correctly determining what really good poems a human would write, does not necessarily create really good poems, any more than a simulator that reasons perfectly about high gravity necessarily produces high gravity.
Let’s discuss this. Your argument presupposes that the item of interest (qualia in your version) is either a physical phenomenon, or else “soul” stuff (what I’ll call supernatural). First of all, are really good poems either physical phenomena or supernatural? Are those our only two options? Really good poems don’t have mass. They don’t have velocity. They don’t have a specific number of atoms making them up. You could take a really good poem written in pencil on paper and then write it again by carving it into a stone. All this suggests that we probably don’t want to call really good poems “physical phenomena”. But then neither do we want to call them supernatural (“soul”-based). There’s nothing supernatural about really good poems. A really good poem is just a specific text, and a text is—I would personally be inclined to say—neither a physical phenomenon, or supernatural.
So then why can’t the same be true of qualia? Texts seem to fall into a third category apart from physical phenomena or supernatural phenomena. Why not qualia?
Or maybe you are inclined to say that texts are physical, meaning that specific instantiation of a text can supervene on physical phenomena. That’s the problem with words like “physical” in the context of a philosophical argument: you can never quite tell what the other guy means by them. So on this alternative interpretation of “physical phenomena” I can ask: why can’t the same be true of qualia? Qualia supervene on physical phenomena, but just as the exact same text can supervene on a very wide range of physical phenomena (e.g. it can be carved in stone, written on paper, spoken aloud, encrypted and sent on microwaves, and so on in enormous variety), the exact same qualia for all we know can supervene on a very wide range of physical phenomena.
Can a simulation produce a really good poem? Well, you’ve stipulated that the simulation can “reason perfectly” about the subject (you said qualia, which I switched to really good poems). I don’t see anything barring the simulator from producing really good poems. So why not qualia?
Let’s go further in your text. You write:
Hence, the type of qualia that a simulator actually produces (if any) depends crucially on the actual physical form of that simulator. A machine which walks the way a human walks must have the form of a human leg. A machine which grips the way a human grips must have the form of a human hand. And a machine which experiences the way a human experiences must have the form of a human brain.
Let’s switch out “qualia” here and switch in “really good poems”. Does the type of really good poem depend crucially on the actual physical form of its physical instantiation? If I take a Shakespeare sonnet, and write it once in pencil, once in ink, and once in smoke from a skywriting plane, did the type of poem change at all? Which of these three instances is not a sonnet?
The poem doesn’t exist—or, depending on what word games you want to play with “exist”, it exists before it’s written. Before anyone can experience the poem, you need to put it into a medium: pencil, ink, smoke, whatever. Their experience of it is different depending on what medium you choose. Your thesis seems to be that when we’re talking about qualia, rather than poems, that the “information” in it is all that matters. In response I refer you to the “ETA” at the bottom of my post.
The poem doesn’t exist—or, depending on what word games you want to play with “exist”, it exists before it’s written.
The poem is the type, the specific instance of the poem is the token. Types do, in a sense, exist before the first token appears, but this hardly renders instances of poems different from, say, apples, or brains. Everything has a type. Apples have a type.
The point remains: the type “Shakespeare’s first sonnet” can be instantiated in ink or in pencil. This has nothing to do with the fact that the type “Shakespeare’s first sonnet” exists before it’s instantiated—because all types do (in the relevant sense).
Before anyone can experience the poem, you need to put it into a medium: pencil, ink, smoke, whatever. Their experience of it is different depending on what medium you choose.
Only because these media are distinguishable. I could write the poem down in india ink, or in, say, watercolor carefully done to look exactly like india ink, and as long as the two instances of the poem are indistinguishable, the reader’s experience need not be any different.
How can we tell what the written poem looks like to the reader? We can ask the reader! We can ask him, “what does it look like”, and on one occasion he might say, “it looks like ink”, and on anther occasion he might say, “it looks like smoke”. But we can do the same with the simulated person reading a simulated ink copy of Shakespeare’s first sonnet. Assuming we have some way to contact him, we can ask him, “what does it look like,” and he might say, “it looks like ink”.
Their experience of it is different depending on what medium you choose.
Maybe. But the central experience is the same. Maybe there’s a difference between experiencing consciousness as implemented on a real brain versus consciousness as implemented inside a simulator. So long as it is possible to implement consciousness in different media, simulations make sense. If you’re really a simulator’s subroutine and not a physical brain, you wouldn’t feel the difference, because you wouldn’t know the feeling of having a real brain.
Let’s replace qualia with some other phenomenon closely associated with the mind but less confusing. How about this: a poem. A really good poem, the sort of poem that we have not seen from anyone but the greatest human poets working at the peak of their art. So, let’s rewrite the above but replacing qualia with really good poems.
Let’s discuss this. Your argument presupposes that the item of interest (qualia in your version) is either a physical phenomenon, or else “soul” stuff (what I’ll call supernatural). First of all, are really good poems either physical phenomena or supernatural? Are those our only two options? Really good poems don’t have mass. They don’t have velocity. They don’t have a specific number of atoms making them up. You could take a really good poem written in pencil on paper and then write it again by carving it into a stone. All this suggests that we probably don’t want to call really good poems “physical phenomena”. But then neither do we want to call them supernatural (“soul”-based). There’s nothing supernatural about really good poems. A really good poem is just a specific text, and a text is—I would personally be inclined to say—neither a physical phenomenon, or supernatural.
So then why can’t the same be true of qualia? Texts seem to fall into a third category apart from physical phenomena or supernatural phenomena. Why not qualia?
Or maybe you are inclined to say that texts are physical, meaning that specific instantiation of a text can supervene on physical phenomena. That’s the problem with words like “physical” in the context of a philosophical argument: you can never quite tell what the other guy means by them. So on this alternative interpretation of “physical phenomena” I can ask: why can’t the same be true of qualia? Qualia supervene on physical phenomena, but just as the exact same text can supervene on a very wide range of physical phenomena (e.g. it can be carved in stone, written on paper, spoken aloud, encrypted and sent on microwaves, and so on in enormous variety), the exact same qualia for all we know can supervene on a very wide range of physical phenomena.
Can a simulation produce a really good poem? Well, you’ve stipulated that the simulation can “reason perfectly” about the subject (you said qualia, which I switched to really good poems). I don’t see anything barring the simulator from producing really good poems. So why not qualia?
Let’s go further in your text. You write:
Let’s switch out “qualia” here and switch in “really good poems”. Does the type of really good poem depend crucially on the actual physical form of its physical instantiation? If I take a Shakespeare sonnet, and write it once in pencil, once in ink, and once in smoke from a skywriting plane, did the type of poem change at all? Which of these three instances is not a sonnet?
The poem doesn’t exist—or, depending on what word games you want to play with “exist”, it exists before it’s written. Before anyone can experience the poem, you need to put it into a medium: pencil, ink, smoke, whatever. Their experience of it is different depending on what medium you choose. Your thesis seems to be that when we’re talking about qualia, rather than poems, that the “information” in it is all that matters. In response I refer you to the “ETA” at the bottom of my post.
The poem is the type, the specific instance of the poem is the token. Types do, in a sense, exist before the first token appears, but this hardly renders instances of poems different from, say, apples, or brains. Everything has a type. Apples have a type.
The point remains: the type “Shakespeare’s first sonnet” can be instantiated in ink or in pencil. This has nothing to do with the fact that the type “Shakespeare’s first sonnet” exists before it’s instantiated—because all types do (in the relevant sense).
Only because these media are distinguishable. I could write the poem down in india ink, or in, say, watercolor carefully done to look exactly like india ink, and as long as the two instances of the poem are indistinguishable, the reader’s experience need not be any different.
How can we tell what the written poem looks like to the reader? We can ask the reader! We can ask him, “what does it look like”, and on one occasion he might say, “it looks like ink”, and on anther occasion he might say, “it looks like smoke”. But we can do the same with the simulated person reading a simulated ink copy of Shakespeare’s first sonnet. Assuming we have some way to contact him, we can ask him, “what does it look like,” and he might say, “it looks like ink”.
Maybe. But the central experience is the same. Maybe there’s a difference between experiencing consciousness as implemented on a real brain versus consciousness as implemented inside a simulator. So long as it is possible to implement consciousness in different media, simulations make sense. If you’re really a simulator’s subroutine and not a physical brain, you wouldn’t feel the difference, because you wouldn’t know the feeling of having a real brain.