Swamp Mary vs. The Anti-Physicalists

Ignore the part about the hoax.

It’s Swamp Mary Season here at Brain Hammer. Starting very soon, I’ll be serializing my new paper, “Swamp Mary Semantics: A Case for Physicalism Without Gaps.”  But before jumping into that, I here offer a précis of the paper that it’s a sequel to, “Swamp Mary’s Revenge: Deviant Phenomenal Knowledge and Physicalism,” forthcoming in Philosophical Studies.


Swamp Mary

Swamp Mary is intrinsically physically identical to Jackson’s Mary after Mary has seen red. Mary knows what it’s like to have experiences of red. Swamp Mary has popped into existence, swamp style, without ever having a mental state with a red quale. But by being physically intrinsically identical to Mary, Swamp Mary has phenomenal knowledge in spite of their extrinsic differences. Swamp Mary knows what it’s like.


Some physicalists say this spells trouble for antiphysicalists. Some antiphysicalists say that they can embrace the possibility of Swamp Mary without any problems, since the possibility of Swamp Mary is consistent with denying that pre-release Mary can deduce the phenomenal facts from the physical facts.


I present two lines of argument against such antiphysicalists: The Psychosemantic Argument and the Factivity Argument.


The Psychosemantic Argument

If Swamp Mary has phenomenal knowledge, there must be some psychosemantic account of how a state of her constitutes a representation of the relevant phenomenal facts. There are four general approaches to psychosemantics: 1. Quotation, 2. Actual Cause, 3. Descriptive-isomorphism, and 4. Nomological. Approaches 1, 2, &3 are unavailable to the targeted antiphysicalists for the following respective reasons: (1), since Swamp Mary is stipulated  to lack red qualia her concepts are not quotations of them, (2) for similar reasons, a red quale cannot have actually caused her concepts, (3) since antiphysicalists hold a red quale to be an ontological simple, it cannot be represented via the structural features essential to Descriptive-isomorphism. This leaves Nomological as the most promising psychosemantic approach for the antiphysicalist who would embrace Swamp Mary. But a problem that arises is that the requisite antiphysical psych-physical laws are arguably unknowable. And if the antiphysicalist dodges this problem by insisting that the laws don’t need to be knowable, then they are left especially vulnerable to the factivity argument.


The Factivity Argument

Let “D” stand for a massive conjunction exhaustively describing, in an exclusively physical vocabulary, the total current state of a deviant. Let “Q” stand for what it’s like to see red, a proposition of the form What it’s like to see red is such-and-such. Let “KQ” be the application of an epistemic modal operator to “Q” so that “KQ” is red as “It is known that Q”. Let “–>” be, at a minimum, an implication operator exhibiting transititvity. I will interpret it as material implication for now and will address a bit later whether it needs some other interpretation for the argument to adequately target Nondeducibility. Let “Deducibility” be the negation of the antiphysicalists’s Nondeducibility claim (that phenomenal facts are nondeducible from physical facts). The factivity argument, then, is as follows.

P1.             D –> KQ

P2.             KQ –> Q

C1.             D –> Q

C2.             Deducibility

The most promising line of response for the antiphysicalist to respond to the factivity argument is to claim that pre-release Mary cannot, via deduction, get herself into a state that has as its content, Q. But this is to maintain a psychosemantic asymmetry between pre-release Mary (“pre-Mary”) and Swamp Mary. What psychosemantics can account for this asymmetry? Both Quotation and Actual-cause are out of the question, since they both inapplicable to pre-Mary and Swamp Mary. And the ontological simplicity of qualia continues to make Descriptive-isomorphism unavailable to the targeted antiphysicalists. All that’s left, then, is Nomological. And here it’s hard to see that the necessary asymmetry between pre-Mary and Swamp Mary can be maintained. Since pre-Mary is nomologically “locked on” to every physical property, and Swamp Mary is nomologically locked on to the relevant phenomenal property, there seems to be no bar to pre-Mary’s psychosemantically “piggy backing” on these nomological chains linking to a red quale that pre-Mary has never experienced. Swamp Mary may thus be used to secure reference to an unobservable much in the way that typically happens with scientific instruments and unobservables like electrons and radio waves.


4 Responses to “Swamp Mary vs. The Anti-Physicalists”

  1. djc says:

    Fun case. Here’s what I (in effect) say about it in “The Content and Epistemology of Phenomenal Belief:

    “As with direct phenomenal concepts, the content of standing phenomenal concepts [those that don't derive from a current experience] does not conceptually supervene on the physical. A question arises as to what determines their content. I will not try to analyse that matter here, but I think it is plausible that their content is determined by some combination of (1) non-sensory phenomenal states of a cognitive sort, which bear a relevant relation to the original phenomenal quality in question — e.g. a faint Humean phenomenal “idea” that is relevantly related to the original “impression”; (2) dispositions to have such states; and (3) dispositions to recognize instances of the phenomenal quality in question.”

    As far as I can tell, these three options are distinct from the four options you consider.

  2. Pete Mandik says:

    Thanks, Dave.

    What do you think of the suggestions that (1) be assimilated to some combination of Quotation and Actual-cause and that (2)&(3) be assimilated to Nomological?

    Re: (1), the way I usually think of the Humean account is that ideas, representing impressions in virtue of being *copies* of them, are, in the usual case at least, both causal consequences of them (thus Actual-cause) and bear first-order resemblances to them (thus Quotation). If a Swamp being has Humean ideas of impressions she’s never had, she’s got quasi-copies that satisfy the resemblance criterion but not the etiological one.

    Re: (2)&(3), my thought is that if P has a disposition to Q, then P has some property, R, constituting a categorical base that (in concert with various triggering conditions) is nomically related to Q. But maybe there are dispositions without laws? I’m not very up on the relevant literature.

  3. djc says:

    Well, assimilate however you want, but the question then is whether your arguments against those options are any good against these options. On the faint copy view, obviously your argument against quotation/actual-cause will get no purchase against a version of this view that doesn’t have a causal requirement. On the dispositional view, your argument against the nomological view gets no purchase, as knowability seems beside the point here. Perhaps it’s knowable whether someone has a disposition to recognize phenomenally red experiences, perhaps not, but either way we may have good grounds to hold that *if* they have such a disposition, they have states with relevant content. And re the factivity argument, it’s obvious that Swamp Mary has a recognitional disposition here that pre-release Mary lacks.

    — and if it’s unknowable, this

  4. Pete Mandik says:

    On versions of the faint copy view that don’t have the causal requirement, all that’s left is the requirement that the idea and the impression share a quale. But Swamp Mary is stipulated to lack a red quale, so the Humean faint copy view can’t account for the psychosemantic grounding of her phenomenal knowledge.

    Re: nomological psychosemantics and the factivity argument, someone pursuing such a line needs to give an account of why it is that there’s a cognitive/epistemic asymmetry (stated in terms of recognitional capacities or whatever) between Swamp Mary and pre-release Mary. It begs the question against those (like me and Dennett) who argue that there is no asymmetry to say that it’s obvious that there is. We deny that there’s anything Swamp Mary is disposed to recognize that pre-release Mary isn’t also capable of recognizing.