Brain Hammer has moved

June 5th, 2009

Brain Hammer has moved to Please manipulate your control surfaces accordingly.

Running Brain Hammer on Wordpress hosted at Globat has been a giant nightmare. For instance, comments got closed by gremlins, not me. Also, I think a chupacabra has been nibbling on some wires. Anyway, hopefully the brain juices will flow more freely now that we have a new vat.

Drop by the new locale and say ‘hi’ or just leave a devastating objection or two. The next installment of the Swamp Mary series has already been posted there.



Nomological Psychosemantics in the Swamp

June 1st, 2009

In the swamp.

To see why Nomological is incompatible with Mary’s prerelease ignorance, it helps to first notice a very natural account that Nomological is able to give for knowledge of unobservables. Unobservable entities like electrons and radio waves are not detectable by the unaided senses. We may just as well state this fact by saying that there’s no law that directly relates sensory states to unobservables.  However, some unobservables are detectable via the use of instruments. This later fact may just as well be stated by saying that there’s a law that relates instrument states to unobservables and another law that relates sensory states to instrument states. Electrons are not nomically related to tokenings of my electron concept in as direct a way as horses are to tokenings of horse. However, via mediating tokenings of instrument states, my electron concept is nonetheless psychosemantically grounded in electrons. Or at least, that is the story available to adherents of Nomological.

            The trouble that arises for the gappy physicalists is that just as Mary may think about electrons that she’s never directly perceived, but detected via instrumentation, thus may Mary exploit Swamp Mary (or anyone else who knows what its like to see red) to think about a red quale. A person who has phenomenal knowledge is nomically related, so says Nomological, to red quale, and Mary, being physically omniscient, is nomically related to every physical state of a person who has phenomenal knowledge.

            The trouble that Nomological presents to gappy physicalists is that Mary may utilize anyone who has phenomenal knowledge in much the same way as she uses measuring instruments. Prerelease Mary may even use Swamp Mary as an instrument.

It is no objection that Mary is in no position to herself calibrate such an “instrument.” Such an objection would say that since prerelease Mary doesn’t know what its like to see red, Mary is in no position to know that her instruments are detecting phenomenal redness instead of phenomenal greenness (or nothing at all). There are two main reasons why such an objection is quite poor. The first is that the objection simply begs the question against gappy physicalism, since non-gappy physicalists deny that prerelease Mary is phenomenally ignorant. The second reason is that it is quite natural to suppose that, for many of us, our capacity to think about unobservables is mediated by chains including instruments that we are not ourselves in a position to calibrate. I have no idea how to calibrate a machine for the detection of electrons. However, if Nomological is correct, then as long as some such device is so calibrated, it can serve as a link in the nomic chain relating my electron tokenings to electrons.

Previous posts:

1. Swamp Mary Semantics: A Case for Physicalism Without Gaps

2. There’s Something About Swamp Mary

3. Putting the Physicalism in Gappy Physicalism

4. Swamp Mary and the Psychosemantic Challenge

Swamp Mary and the Psychosemantic Challenge

May 29th, 2009

Swamp swamps swamp swamp swamps.


There are two general approaches to the psychosemantics of phenomenal knowledge in normal subjects that are quite easy to see as totally doomed to fail to account for the psychosemantics of Swamp Mary’s phenomenal knowledge. The first approach imposes as a necessary condition phenomenal representation (the representation of phenomenal properties) that it involve a kind of quotation or exemplification whereby, for instance, the concept of a red quale is partially constituted by a red quale (as in Papineau (2002), though he retreats somewhat from the view in his (2007)). On such a view, just as a carpet sample of a red carpet must exemplify the same color and texture of the carpet it samples, so must the phenomenal concept have the same phenomenal character as the experience it is a concept of. The notion of representation by exemplification here is the same as the one discussed by Goodman (1976, pp. 52-67). The second approach grounds phenomenal representation in a causal relation to some actual past occurrence of a red quale. The quotation approach fails for the following reason. Since Swamp Mary lacks a red quale, her phenomenal knowledge cannot be grounded in quoting or exemplifying a red quale. The causation approach likewise fails. Since Swamp Mary need not have any actual past, her phenomenal knowledge cannot be grounded in causal relations to past qualia occurrences.

Let us turn, then, to look elsewhere for a psychosemantics to ground Swamp Mary’s phenomenal knowledge. There are two worth investigating. promising, each of which relate rather directly to the two key features of physicalism described in the previous section.

The first line for exploration is to ground Swamp Mary’s phenomenal knowledge in some kind of nomic or counter-factual relation to qualia, qualia that she need not actually have had. Such a psychosemantics may be modeled on the sort of nomological approach favored by Fodor (Fodor, 1987).Since the physicalists affirm the causal efficacy of qualia, its open to posit that there are counter-factual-supporting laws that subsume qualia. Such laws may very well relate qualia to concepts of qualia (as well as non-conceptual representations of qualia). So, even though Swamp Mary has never had a red quale, she is in a state that would be causally related to red qualia in certain counter factual scenarios. She would, for instance, go into a state of recognition if she later were appropriately causally related to a red quale. Further, the state she is in is of a type tokens of which can be caused by red qualia.

The second line for exploration is to ground Swamp Mary’s phenomenal knowledge in terms of some kind of structural commonality between her knowledge state and red qualia. Instances of this general psychosemantic approach include description theories (e.g., (Russell, 1905), isomorphism-based theories (e.g., (Cummins, 1996), and conceptual role semantics (e.g.(N. Block, 1986; Sellars, 1953). An approach of this sort is available to the physicalist since the physicalist affirms the ontological complexity of qualia. For certain anti-physicalists, the ontological simplicity of qualia leads directly to their ineffability and recalcitrance to analysis. However, for physicalists, it is open to exploit the ontological complexity of qualia and account for Swamp Mary’s phenomenal representations as, e.g., descriptions that capture defining structural features of a red quale.

Let us call the two approaches just sketched Nomological and Descriptive-isomorphism, respectively. They show some initial promise for underwriting Swamp Mary’s phenomenal knowledge. They are consistent with the physicalist part of gappy physicalism. However, to be consistent with the gappy part of gappy physicalism, these approaches have to also be consistent with the claim of Mary’s prerelease ignorance. And this is where the trouble arises for gappy physicalism. In the next post, I argue that neither Nomological nor Descriptive-isomorphism is compatible with Mary’s prerelease ignorance.

Previous posts:


1. Swamp Mary Semantics: A Case for Physicalism Without Gaps

2. There’s Something About Swamp Mary

3. Putting the Physicalism in Gappy Physicalism

Putting the Physicalism in Gappy Physicalism

May 25th, 2009

Physicalism: efficacy and complexity.


I’ve already said what is gappy about gappy physicalism [link]. I turn now to say a few key remarks about the physicalism of gappy physicalism. It is difficult to give a satisfactory full account of what physicalism is supposed to consist in. (This has been pointed out by several authors. See, e.g., Montero & Papineau (2005).) Fortunately we can make do in the current discussion by identifying a few key features. There are two and both concern qualia. Crucial aspects for the current paper are the ontological complexity and causal efficacy of qualia.

According to physicalism, no ontological simples are phenomenal. If there are ontological simples, that is, if it isn’t complexes all the way down, they are non-phenomenal. This sketch allows us to bypass the vexing question of what exactly it is that makes something physical. It will serve the purposes of the present paper to contrast physicalists from anti-physicalist opponents such as dualists to characterize one of the core doctrines of physicalism as the view that everything phenomenal is ontologically complex and that these complexes ultimately resolve into comparative simples that are non-phenomenal.

The second core doctrine of physicalism of note for the current discussion is that, according to physicalism, no qualia lack physical effects. The physicalist holds that one and the same property that is a mental state’s being such that there’s something it’s like to have it also is one of the causal powers of the mental state. Physicalists, then, deny qualia epiphenomenalism.

Previous posts:

1. Swamp Mary Semantics: A Case for Physicalism Without Gaps

2. There’s Something About Swamp Mary

There’s Something About Swamp Mary

May 22nd, 2009

Phenomenal fact fight.


In this, the second post in the series, “Swamp Mary Semantics: A Case for Physicalism Without Gaps,” I spell out some further crucial details of the central thought experiment.

Given the trouble I claim to be raised for gappy physicalists by Swamp Mary, it is natural to consider possible grounds that gappy physicalists might have for rejecting as impossible one or more aspects of the Swamp Mary scenario.

There seems to be no basis for gappy physicalists to deny that a being can be intrinsically identical to post-release Mary and never have experienced a red quale. That such a complicated entity can spring into being fully formed by quantum accident is of course highly improbable, but it is not impossible. Further, possible events of such high improbability are the bread and butter of gappy physicalists relying, as much as they do, on the conviction that there could be a physically omniscient yet phenomenally ignorant Mary.

Someone who finds it easy to grant the possibility of a person forming Swamp-style might nonetheless resist granting the possibility of a being physically intrinsically identical to post-release Mary who, the Swamp being, lacks a red quale. A useful means for overcoming such resistance is to imagine that post-release Mary has been knocked out with a general anesthetic. It is natural to assume that a person under a general anesthetic has no experiences (otherwise, general anesthesia is misnamed). Thus, if Swamp Mary pops into existence intrinsically physically identical to generally anesthetized post-release Mary, then Swamp Mary does not at that time have a red quale.

But would a generally anesthetized Swamp Mary, lacking a red quale, nonetheless know what it’s like to have a red quale? Prima facie, Swamp Mary does, since, despite being generally anesthetized, post-release Mary does. Anesthetics are not, generally, amnestics, and Mary, having learned what it’s like to see red, need not forget it or anything else when she’s put under.

            Of course, to assume that Swamp Mary has phenomenal knowledge of a quale she’s never yet experienced is to assume that phenomenal knowledge does not supervene on historical relations to particular past events. Call such an assumption ahistoricism and its negation, historicism. Might gappy physicalists dodge Swamp Mary by insisting on historicism about phenomenal knowledge? This is a difficult question to assess, but it helps to look at the relative merits of historicism as applied to other kinds of knowledge.

            Probably the cases most crying out for historicism are cases wherein the knowledge in question concerns putative particular past events concerning the knower herself. It is quite strained to say of Swamp Mary that she knows what happened to Mary nine years ago even though she may have an internal state physically similar to a state that Mary is in when Mary correctly remembers what happened to her nine years ago. There is no nine years ago for Swamp Mary, and her state is a mere quasi-memory.

We might summarize by saying that the case for historicism is strongest when it is applied to putative knowledge that is both historical and egocentric. Crucially, knowledge of historical egocentric facts involves knowledge of particulars, knowledge of particular past events concerning a particular person.

            When we shift our attention from knowledge of particulars to knowledge of generalities, the intuitive pull of historicism weakens considerably. While it may have a high degree of plausibility to claim that a newly-minted Swamp-being cannot count as retaining first-hand knowledge of autobiographical events from nine years ago, it is comparatively less plausible to claim that the same Swamp being can’t know that nine years ago is five years ago plus four years ago. Pieces of knowledge that have a high degree of generality, like that twice four is eight and that everything is self-identical, are harder to deny attributing to our Swamp doubles.

            The question to ask, then, of phenomenal knowledge, since we are interested in whether Swamp Mary really has any, is whether phenomenal knowledge is more appropriate to think of as general or particular. And here I think that a stronger case can be made for the generality rather than the particularity of phenomenal knowledge. As pointed out in Mandik (2001), the common intuition regarding Mary is that she learns not only what it is like for her to see red, but she is also in a position to grasp what it must be like for others to see red as well.

Of course, it is not unheard of for philosophers to take a very hard line on Swamp beings. Dretske (1995), for instance defends an etiological teleosemantic version of representationalism about qualia wherein it’s a requirement on having any conscious experiential content that a creature have a certain evolutionary history. On a Dretskean account, Swamp Mary, even un-anesthetized and staring at a red rose, wouldn’t have any red qualia and a fortiori, wouldn’t know what it’s like to have red qualia.

Might a gappy physicalist adopt a strong historicism to protect against the threat of Swamp Mary? A problem that arises here seems to be that very strong externalism such as the one that leads to Dretske’s historicism is likely to be inconsistent with Mary’s prerelease phenomenal ignorance (see Dretske (1995, pp. 81-95)) On Dretske’s view, what it’s like to experience red is to be in a state that bears certain historico-evolutionary relations to red surfaces. If Mary knows what surface properties a color-sighted person is historico-evolutionarily related to, then the fact that Mary has never herself entered into such relations is no bar to her knowing what it’s like for a color-sighted person to see red. On Dretske’s view, Mary may lack experiential representations of red surfaces, but this is no bar to her having representations of such surfaces in thought, and it is her thought representations that underwrite her knowing what it is like to have experiences that she has not herself had.

            While these remarks about Dretske have been brief, I take them to cast doubt on the prospects of gappy physicalists blocking the threat of Swamp Mary by denying her very possibility.

 Previous posts:

1. Swamp Mary Semantics: A Case for Physicalism Without Gaps


Gold and Roskies on Philosophy of Neuroscience

May 21st, 2009

The following link [link] is to a Google books version of the following overview of the philosophy of neuroscience by Ian Gold and Adina Roskies:

Gold, I., & Roskies, A. (2008). Philosophy of Neuroscience. In The Oxford Handbook of Philosophy of Biology (pp. 349-380): Oxford University Press.


Swamp Mary Semantics: A Case for Physicalism Without Gaps

May 20th, 2009

Welcome to my weird adventure.


Here begins the first post in the serialization of my work in progress, “Swamp Mary Semantics: A Case for Physicalism Without Gaps,” sequel to “Swamp Mary’s Revenge: Deviant Phenomenal Knowledge and Physicalism,” forthcoming in Philosophical Studies.


            I argue for the superiority of non-gappy physicalism over gappy physicalism. While physicalists are united in denying an ontological gap between the phenomenal and the physical, the gappy affirm and the non-gappy deny a relevant epistemological gap. Central to my arguments will be contemplation of Swamp Mary, a being physically intrinsically similar to post-release Mary (a physically omniscient being who has experienced red) but has not herself (the Swamp being) experienced red. Swamp Mary has phenomenal knowledge of a phenomenal character not instantiated by any of her past or current mental states. I issue a challenge to gappy physicalists to account for how it is that Swamp Mary can satisfy the psychosemantic requirements on phenomenal knowledge while non-Swamp pre-release Mary cannot. I argue that gappy physicalists cannot meet this psychosemantic challenge.

1. Introduction

            Physicalism is under threat, so the story goes, from an epistemic gap that exists between physical facts and phenomenal facts (Chalmers, 2003). Many qualia-based antiphysicalisms are based on inferring an ontological gap from the epistemic gap, the latter gap variously characterized in terms of what can be known, conceived, or explained. For example, in the famous argument concerning colorblind super-neuroscientist Mary (Jackson, 1982), it is inferred that physical facts cannot exhaust the totality of facts since Mary may be physically omniscient without thereby knowing what it is like to see red.

            One line of physicalist defense, a line that it will be the main aim of the present paper to criticize, involves embracing the epistemic gap while denying the ontological gap. I shall call such physicalists gappy physicalists. One of the most prominent versions of gappy physicalism is what has been referred to as the phenomenal concept strategy (Stoljar, 2005). Advocates of this strategy include Loar (1990), Balog (forthcoming), Block (2006), Papineau (2002; 2007), Tye (2000), and Perry (2001). The gist of what phenomenal concepts are supposed to be may be conveyed in terms of Mary: what she learns upon learning what it is like to see red is constituted by the acquisition of a new concept that puts her in a position to conceive of old facts in a new way. The epistemic gap thus opens up because of a gap between two different kinds of concept, phenomenal concepts and physical concepts, not a gap between two kinds of properties or two kinds of facts.

            Not all gappy physicalists are advocates of the phenomenal concept strategy. For example, Prinz’s (2007) “mental pointing” account postulates non-conceptual phenomenal demonstratives to account for the gap between Mary’s  pre- and post-release knowledge. Tye (2009), having terminated his allegiance to the phenomenal concepts strategy, nonetheless attempts to maintain allegiance to gappy physicalism via the postulation of physicalistically respectable version of knowledge by acquaintance. What unites gappy physicalists (besides, of course, their physicalism) is their holding that phenomenal knowledge is a kind of factual knowledge distinguished from physical knowledge not by what facts it is knowledge of but in how certain physical facts are represented.

A physicalist thesis hinging on how certain facts are represented incurs an obligation to, if not give a physicalistic explanation of representation, at least not violate physicalistic requirements on what representation can be. The purpose of the present paper is to articulate a criticism that applies to all gappy physicalists by calling into question their ability to satisfy physicalist psychosemantic strictures on phenomenal knowledge.

Central to my criticism will be drawing certain consequences of the Swamp Mary thought experiment (Alter, 2008; Dennett, 2005; P. Mandik, in press). Key features of Swamp Mary are that (1) she is intrinsically physically identical to post-release Mary, (2) she knows what it’s like to see (hallucinate, afterimage, etc.) red, and (3) she has sprung into being without herself ever having had a mental state with a red quale. The core consequence of the Swamp Mary thought experiment that I will draw is that gappy physicalists cannot account for how it is that Swamp Mary does, while pre-release Mary does not, satisfy the psychosemantic criteria for knowing what it’s like to see red. In previous work (Mandik, in press) I develop a case against antiphysicalism based on psychosemantic asymmetries between pre-release Mary and Swamp Mary. I will not recount those arguments here and instead proceed by assuming physicalism and developing a critique of gappy physicalism.

            The structure of the remainder of the paper is as follows. In §2, I lay out further preliminaries, including further relevant details of gappy physicalism and the Swamp Mary scenario. In §3, I discuss the broad outlines of various physicalistic theories of content that might possibly underwrite the psychosemantic requirements on phenomenal knowledge. I then spell out how gappy physicalists are incapable of rising to the psychosemantic challenge of explaining how it is that Swamp Mary can represent the phenomenal facts as phenomenal without it also being the case that pre-release Mary can do so as well. In §4 I spell out a suggestion that physicalists abandon attempts to explain an epistemic gap (there being none) and devote their energies instead to explaining why there ever appeared to be an epistemic gap in the first place. I also present some speculations as how such explanations might best proceed.



Alter, T. (2008). Phenomenal Knowledge Without Experience. In E. Wright (Ed.), The Case for Qualia (pp. 247-267). Cambridge, MA: MIT Press.

Balog, K. (forthcoming). In Defense of the Phenomenal Concept Strategy. Philosophy and Phenomenological Research.

Block, N. (1986). Advertisement for a semantics for psychology. Midwest Studies in Philosophy, 10, 615-678.

Block, N. (2006). Max Black’s objection to mind-body identity. Oxford Review of Metaphysics, 3.

Chalmers, D. (2003). Consciousness and its Place in Nature. In S. Stich & F. Warfield (Eds.), Blackwell Guide to Philosophy of Mind. Oxford: Blackwell.

Cummins, R. (1996). Representations, Targets, and Attitudes: MIT Press.

DeLancey, C. (2007). Phenomenal experience and the measure of information. Erkenntnis, 66(3), 329-352.

Dennett, D. C. (2005). Sweet Dreams: Philosophical Obstacles to a Science of Consciousness: MIT Press.

Dretske, F. (1995). Naturalizing the Mind. Cambridge, MA: MIT Press.

Fodor, J. A. (1987). Psychosemantics: The Problem of Meaning in the Philosophy of Mind: MIT Press.

Goodman, N. (1976). Languages of art: Hackett Indianapolis.

Jackson, F. (1982). Epiphenomenal Qualia Philosophical Quarterly, 32, 127-136.

Jacobson, H. (1950). The Informational Capacity of the Human Ear. Science, 112(2901), 143-144.

Jacobson, H. (1951). The Informational Capacity of the Human Eye (Vol. 113, pp. 292-293): the American Association for the Advancement of Science.

Koch, K., McLean, J., Segev, R., Freed, M. A., Berry, M. J., Balasubramanian, V., et al. (2006). How Much the Eye Tells the Brain. Current Biology, 16(14), 1428-1434.

Levine, J. (2007). Phenomenal Concepts and the Materialist Constraint. In T. Alter & S. Walter (Eds.), Phenomenal Concepts and Phenomenal Knowledge: New Essays on Consciousness and Physicalism: Oxford University Press.

Lewis, D. (1990). What Experience Teaches. In W. Lycan (Ed.), Mind and Cognition (pp. 499–518). Cambridge: Basil Blackwell.

Loar, B. (1990). Phenomenal states. In J. Tomberlin (Ed.), Philosophical Perspectives 4: Action Theory and Philosophy of Mind (pp. 81-108). Atascadero, CA: Ridgeview.

Mandik, P. (2001). Mental Representation and the Subjectivity of Consciousness. Philosophical Psychology, 14(2), 179-202.

Mandik, P. (in press). Swamp Mary’s Revenge: Deviant Phenomenal Knowledge and Physicalism. Philosophical Studies.

McBride, T., Arnold, S. E., & Gur, R. C. (1999). A Comparative Volumetric Analysis of the Prefrontal Cortex in Human and Baboon MRI. Brain, Behavior and Evolution, 54(3), 159-166.

Montero, B., & Papineau, D. (2005). A defense of the via negativa argument for physicalism. Analysis, 65(287), 233-237.

Papineau, D. (2002). Thinking about Consciousness. New York: Oxford University Press.

Papineau, D. (2007). Phenomenal and perceptual concepts. In T. Alter & S. Walter (Eds.), Phenomenal Concepts and Phenomenal Knowledge: New Essays on Consciousness and Physicalism: Oxford University Press.

Perry, J. (2001). Knowledge, possibility, and consciousness: MIT Press.

Prinz, J. (2007). Mental Pointing: Phenomenal Knowledge Without Concepts. Journal of Consciousness Studies, 14(9-10), 184-211.

Russell, B. (1905). On Denoting. Mind, XIV(4), 479-493.

Schier, E. (2008). The knowledge argument and the inadequacy of scientific knowledge. Journal of Consciousness Studies, 15(1), 39-62.

Sellars, W. (1953). Inference and Meaning. Mind, LXII(247), 313-338.

Sperling, G. (1960). The information available in brief visual presentations. Psychological Monographs: General and Applied, 74(11), 1-30.

Stoljar, D. (2005). Physicalism and phenomenal concepts. Mind & Language, 20(5), 469-494.

Tipler, F. J. (1995). The Physics of Immortality: Modern Cosmology, God and the Resurrection of the Dead. London: Macmillan.

Tye, M. (2000). Consciousness, Color, and Content. Cambridge, MA: MIT Press.

Tye, M. (2009). Consciousness Revisited: Materialism Without Phenomenal Concepts. Cambridge, MA: MIT Press.

Weiskopf, D. (2007). Concept empiricism and the vehicles of thought. Journal of Consciousness Studies, 14, 156–183.

Philosophy of Neuroscience on PhilPapers

May 20th, 2009

I am now PhilPapers editor for the philosophy of neuroscience and most of its subcategories. I urge Brain Hammer readers with pertinent research to make sure it’s included. See links below. Also, heed the words of Cartman.

Cartman - respect my authority

Swamp Mary vs. The Anti-Physicalists

May 19th, 2009

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.


A brain in the hand

May 18th, 2009

This post is mostly just to test out the WordPress for iPhone app. Also, here’s a screenshot from the free app, Brain Tutor.