A weird escape from the Knowledge Argument?

Take Jackson’s story about Mary who grows up in a black-and-white room, but learns all the science there is, including the physics and neuroscience of color perception. One day she sees a red tomato. The point of the story is that in seeing the red tomato, she has learned something, even though she already knew all the science, so the science is not all the truth there is, and hence physicalism is false.

This story is generally told in the context of the philosophy of mind, and the conclusion drawn is that physicalism about the mind is false. But that does not actually follow without further assumptions. As far as the argument goes, perhaps Mary didn’t learn anything about herself that she didn’t already know, but has learned something about tomatoes, and so we should conclude that physicalism about tomatoes is false.

Let’s explore that possibility and see if this hole in the argument can be filled. I will assume (though I am suspicious of it) that indeed the kind of knowledge gap that Jackson identifies would imply an ontological gap. Thus, I will accept that Mary has learned what it is like to see the red of a tomato, and that the knowledge of what it is like to see the red of a tomato is not a knowledge of physical fact.

Can one say this and yet accept physicalism about the mind? The one story I can think of that would allow that is a version of Dretske’s qualia externalism: just as most of us think that the content of our thoughts is partly constituted by external facts, so too the qualitative character of our perceptions is partly constituted by external facts. But in fact for the story to work as a way of blocking the inference to non-physicalism about the mind, the qualia (understood as that in the experience that cannot be known by Mary by mere book-learning) would need to be entirely constituted by extra-mental facts.

I think this kind of qualia externalism is not all that crazy. Divine simplicity requires that all of God’s knowledge of contingent fact be partly constituted by states of affairs outside God. But it is plausible that God has something like contingent qualia: that were God to contemplate a world with unicorns, it would “look” different to God than our world. On divine simplicity, we would need to have externalism about these qualia.

That said, the above affords no escape from literal anti-physicalism about the mind. If physicalism about the mind is true, then minds are brains. But if we accept that colored things have a nonphysical component that partly constitutes the perceiver’s qualia, then brains have a nonphysical component, since brains are colored things, namely pinkish (here is a description of their color in vivo, though I cannot vouch for its accuracy).

Maybe, though, this misses the point in the debate. The typical dualist thinks that there is something different about minds and other physical things. If it turns out that minds are just brains, but that they are not physical simply because their pinkness is not entirely a physical property, that’s really not what the dualist was after. The dualist’s intuition is that there is something radically different in the human brain, something not found in a pink sunset cloud (unless it turns out that panpsychism is true!).

Maybe this works to save a more robust dualist conclusion: Plausibly, one doesn’t need a tomato to make Mary have a red sensation. All one needs is to do is to induce in her brain’s visual centers the same electrical activity as normally would result from her seeing a red tomato. And the equipment inducing that electrical activity need not be red at all.

Internalism, externalism and Bayesianism

Maybe a Bayesian should be a hybrid of an internalist and an externalist about justification. The internalist aspect would come from correct updating of credences on evidence, internalistically conceived of. The externalist aspect would come from the priors, which need to be well adapted to one's epistemic environment in such a way as to lead reasonably quickly to truth in our world and maybe also in a range of nearby worlds.

This seems a natural way to think about the internalist and externalist question by means of the analogy of designing a Bayesian artificial intelligence system. The programmer puts in the priors. The system is not "responsible" for them in any way (scare quotes, since I don't think computers are responsible, justified, etc--but something analogous to these properties will be there)--it is the programmer who is responsible. Nonetheless, if the priors are bad, the outputs will not be "justified". The system then computes--that is what it is "responsible" for. It seems natural to think of the parts that the programmer is responsible for as the externalist moment in "justification" and the parts that the system is "responsible" for as the internalist moment. And if we are Bayesian reasoners, then we should be able to say the same thing, minus the scare quotes, and with the programmer replaced by God and/or natural selection and/or human nature.

Content externalist solutions to sceptical problems

A standard solution to general sceptical problems is to move to an externalist account of content. Grossly oversimplifying, if what makes a thought be about horses is that it has a causal connection with horses, then thoughts about horses can't be completely mistaken. This sort of move might be thought to be anti-realist, though I think that's a poor characterization. If this sort of move works, then we couldn't have thoughts and yet have our whole system of thoughts be completely mistaken. And hence, it seems, scepticism is dead.
But it just occurred to me that there is a hole in this argument. Why couldn't the sceptic who accepts the externalist story about content still say: "So, if I am thinking at all, then global scepticism is false. But am I thinking at all?" This may seem to be a completely absurd position—how could one doubt whether one is thinking? Wouldn't the doubt be a thought? Yes, the doubt would be a thought. Hence, the person who doubts whether she thinks would not be able to believe that she doubts. And, of course, the person who thinks she's not thinking has a contradiction between the content of her thought and the fact of her thought, but it's not so obvious that that's a contradiction in her thought (just as a contradiction between the content of an astronomical belief and an astronomical fact need not be a contradiction in the thinker's thought). Besides, the Churchlands think that they have no thoughts, and have given arguments for this.
If I am right in the above, then the content externalist move does not solve the problem of scepticism—it simply radicalizes it. But it raises the cost of scepticism—it forces the sceptic to stop thinking of herself as thinking. And as such it may be practically useful for curing scepticism if the sceptic isn't a full Pyrrhonian, in the way a rose or some other creature that has no thoughts is. However, if the motivation for the content externalism is to solve the problem of scepticism, rather than cure the sceptic, then the motivation seems to fail. (One difference between solving and curing is this. If a theory T solves a problem, then we have some reason to think T is true by inference to best explanation. But if believing a theory T would cure someone of a problem, inference to best explanation to the truth of T is not available. Though, still, I think the fact that believing T is beneficial would be some evidence for the truth of T in a world created by the good God.)

Externalism about prudential reasons

Consider this case, which a colleague tells me is standard. You are bleeding badly, and you need to get to the hospital. You get in your car. No ambulance is available. However, unbeknownst to you, your car's ignition is wired to a bomb. What should you, prudentially, do? Suppose you say "Don't go to the hospital, try to self-treat." Why would you say that? Well, it has better consequences than turning on the ignition. Call somebody who says this a "consequences externalist".

But what does it mean to say that it has better consequences than turning on the ignition? I suppose it's because something like this pair of conditionals is true:

1. Were you to turn on the ignition, the bomb would explode and you'd die immediately.
2. Were you not to turn on the ignition, you'd live longer.

But in fact we live in a world that, as far as we know, is suffused with indeterminism. There is a tiny chance that if you turn on the ignition, the electrons from the battery will quantum tunnel around the bomb's igniter and to the car's spark plug. There is a tiny chance that if you don't turn on the ignition, a quantum event will increase the heat in the bomb and make it explode. And so on.

If something like generalized standard Molinism (i.e., Molinism generalized to indeterministic stuff other than free will) is true, (1) and (2) are perfectly well defined. But suppose no such view is true. So, really, all we have at the time of the decision are objective probabilities: it is overwhelmingly likely, given the physical state of the world, that if you turn on the ignition, the bomb will explode and you'll die immediately, etc. So, it seems, the consequences externalist has to be deeming the conditionals true when the probabilities are high enough.

So, it seems, the consequences externalist is saying that you ought not to turn on the ignition because it is exceedingly likely, given the actual arrangement of the universe at the time of the action, that doing so will let you live longer, and it is exceedingly likely that turning on the ignition will not.

Fine. Now imagine that you in fact turn the ignition, the electrons quantum-tunnel around the bomb, and all is well (maybe eventually the bomb quantum-tunnels into the sun, too). This is exceedingly unlikely, but is compatible with everything in the story so far. According to the consequences externalist position I've sketched, you in fact did the wrong thing—even though it had better consequences than the alternative. You did the wrong thing, because at the time of the decision the objective probabilities were against this decision.

But to say that in this case you did the wrong thing goes against the guiding intuitions of the consequence externalist. Once you admit that you might have done the wrong thing even though it had the better consequences, you should probably just abandon the consequence externalism altogether, and move from objective to subjective probabilities.

Now, there is something the consequence externalist can say. She can say that we evaluate subjunctives by probabilities when their antecedents are false, and by consequents when the antecedents are true. This is messy, but not crazy. So, in the case I've described, (1) is false because it has a false consequent and true antecedent, but (2) is true because the objective probability of the consequent given the antecedent is low at the time of the action.

But if the consequence externalist says this, she has the following weird thing to say. She has to say that (a) turning on the ignition was in fact right, but (b) had you not turned on the ignition, turning on the ignition would have been wrong. Why does she have to say (b)? For if you had not turned on the ignition, the subjunctive conditional (1) would have been true. It would have been true because it would have had a false antecedent and hence would have to have been evaluated according to the objective probabilities.

So, oddly, you did the right thing, but had you not done it, it would have been the wrong thing. That is weird indeed.

Communication boards and indexicals (Language, Part I)

This is the first in what may be a series of posts developing a view of language that erases the distinction between language and context. The view may self-destruct before it's fully developed. I'm having fun here. No originality is claimed.

Some disabled people communicate with a communication board. A communication board is a board with printed pictures, some representing objects like shoes and chairs, some representing verbs like sitting, and some representing emotions like happy or sad. One communicates with a communication board by pointing to a sequence of pictures. High-tech communication boards will say the word, but it's important to my argument that I be talking of a low-tech one, which is just a pre-printed board. If a communication board is sufficiently large and extensive, and there is sufficient syntactic structure in the order in which one points to the pictures, this will be a language.

Let's say that the pointing is done with a finger. Now, what are the words or other linguistic units in this language?

Here is a really bad suggestion: The words are constituted by pointings with a finger and two token pointings count as of the same type if and only if the finger directions in the two pointings have the same relationship to the natural axes of the speaker's body (within some measure of precision; I will use the word "speaker" regardless of whether a language is spoken or not). The pictures on the board, on this suggestion, are simply context.

What's wrong with this suggestion? Well, for one, it means that if the speaker points to parent, fruit and happy, expressing (let's suppose) the proposition that the parent is happy with the fruit, and I shift the board over by an inch, and the speaker again points to parent, fruit and happy, then the speaker has used different word types, because her pointings are now in different directions. That is absurd--surely the speaker has said the same sentence.

Another way to see the absurdity of this view is that it will be impossible to give a story about the syntax of the language in terms of the arrangement of word types, since whether a given sequence of finger pointings, identified by direction relative to the speaker's body, is syntactically correct depends crucially on what the pictures pointed to are, and not just on the angles (again, think of a case where the board gets shifted over). But we don't want context to be the primary determiner of syntax!

One might think that the mistake in this story is that it is not the angles relative to the speaker body that matter for identifying the word type, but rather the direction of the finger as measured in some natural coordinate system based on the configuration of the board. (E.g., run the x-axis along the horizontal side of the board, the y-axis along the vertical side, the z-axis upward from the board, and then specify the cartesian coordinates of the tip of the finger and the finger's big joint.) But that's silly, too. Suppose that the speaker's board gets upgraded by getting a few new pictures, and with existing pictures moved a bit to accommodate the new ones. The speaker's language, thus, becomes extended. But now if we identified word types in terms of the coordinates of the finger relative to the board, the same sequence of finger positions as before would now be expressing something completely different. More seriously, previously syntactically correct sequences of word types would no longer be syntactically correct. In other words, we have a completely new language. But that is surely a hamfisted way of describing what happened in the board upgrade. There is something that is obviously wrong with the previous two accounts. The crucial thing to note is that the pictures that are pointed out are not mere context. They are crucial for the syntax: whether a sequence of three pointings is syntactically correct depends precisely on what parts of speech the pictures represent. Clearly, the thing to do is to either identify word-types with the pictures that are pointed out (more precisely: picture-types, in order to allow for upgrades of the board), or with pointings-at-x, where x ranges over the pictures (or picture-types) on the board.

Hypothesis: What happens with the communication board is also what happens with demonstratives. The thing pointed to is not context: it either is a part of the sentence (much as some folks think that items referred to de re are parts of the proposition) or a pointing at (de re) it is a part of the sentence. And something like this happens with all indexicals. At this point I am offering no argument, except the suggestive analogy of the communication board language.

Apparent disanalogy: In the communication board language, it is not the the picture tokens that function as word types (or, equivalently, it is not the pointings-at-picture-tokens), but the types of pictures (or the pointings at a type of picture). But in true demonstratives, there is no similar type/token distinction on the side of the things pointed out. One simply points at Alexander, not at something of the sort of Alexander.

This disanalogy is due to the fact that in a typical communication board, none of the pictures refer to the picture-token there, and that in typical demonstratives, we are trying to refer to particulars. But I submit that these are mere accidents. We could imagine that some of the pictures indicate particulars, like George, Socrates, etc. And there would be nothing absurd about a picture that indicates the picture-token that it is. (Maybe it's a very a beautiful and emotionally significant picture, so it's worth talking about as an individual. When a board is upgraded, it gets scraped off the old board and pasted on the new one.)

Moreover, we do in fact have cases where demonstratives point to a type, it's just that we don't use them quite as much as ones where we point to particulars. We've learned this from Kripke. Point to water and say: "We will call this 'water'." The "this" refers to the natural kind, not the particular bunch of water.