P S Y C H E 11(2): March 2005
Review of P. Ludlow, Y. Nagasawa & D. Stoljar (eds.) There’s Something about Mary
Torin Alter
Department of Philosophy
The University of Alabama
Tuscaloosa, AL 35487-0218
http://www.as.ua.edu/philos/talter
talter@bama.ua.edu
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REVIEW OF: Review of Peter Ludlow, Yujin Nagasawa, and Daniel Stoljar (eds.) There’s Something about Mary: Essays on Phenomenal Consciousness and Frank Jackson’s Knowledge Argument (Cambridge, MA: MIT Press, 2004) 480 pp. US$35 (pbk) ISBN: 0262621894.
(c) Torin Alter 2005
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“There’s Something about Mary” contains:
A lengthy introduction by two of the editors, Daniel Stoljar and Yujin Nagasawa.
Frank Jackson’s classic articles from the 1980’s, “Epiphenomenal Qualia” and “What Mary Didn’t Know,” in which he develops and defends the knowledge argument.
Fifteen articles representing the main lines of response, four of which have not been previously published. The new ones are by David Chalmers, Benj Hellie, Philip Pettit, and Robert van Gulick (Chalmers’ and van Gulick’s articles aren’t wholly new; both elaborate ideas they’ve expressed elsewhere). The rest are by John Bigelow and John Pargetter, Earl Conee, Paul Churchland, Daniel Dennett, Terence Horgan, David Lewis, Brian Loar, Martine Nida-Rümelin, Howard Robinson, Daniel Stoljar, and Michael Tye.
Jackson’s subsequent papers on the topic. These include: a 1995 postscript in which he defends part of the argument; a 1998 postscript and a 2003 article (“Mind and Illusion”) in which he explains why he now rejects the argument; and a new forward in which he further elaborates and defends his current position.
An extensive bibliography of supplemental readings.
The articles vary in quality, but that’s inevitable. The previously published papers are well selected and some of the new material is excellent. This is a useful volume.
The titular ‘Mary’ refers to Jackson’s famous protagonist. Her story takes place in the future, when all physical facts have been discovered. This includes “everything in completed physics, chemistry, and neurophysiology, and all there is to know about the causal and relational facts consequent upon all this, including of course functional roles” (Jackson 1982, p. 51). Mary learns all this by watching lectures on a monochromatic television monitor. But she spends her life in a black-and-white room and has no color experiences. Then she leaves the room and sees colors for the first time.
Jackson devised the Mary case to refute physicalism, the doctrine that the world is merely physical. He reasons as follows. If physicalism is true, then Mary would know everything about human color vision before leaving the room. But intuitively, she learns something new when she leaves the room; she learns what it’s like to see colors, and her new phenomenal knowledge includes knowledge of truths. Therefore, physicalism is false.
That, in brief, is Jackson’s knowledge argument. It has two parts. One says that physical knowledge isn’t sufficient for phenomenal knowledge. Stoljar and Nagasawa call this the knowledge intuition. The other says that the knowledge intuition entails the falsity of physicalism. Thus described, the knowledge argument isn’t new with Jackson. Locke and other 18th Century British empiricists discussed the knowledge intuition; C. D. Broad gave a version of the knowledge argument in 1925; and other versions appear in more recent writings, such as Thomas Nagel’s 1974 “What is it Like to be a Bat?” What is distinctive about Jackson’s contribution, other than the catchy name, “the knowledge argument”?
Stoljar and Nagasawa provide a convincing answer in their splendid introduction. They say Jackson contributes two things: his Mary case illustrates the knowledge intuition better than previous attempts; and he provides distinctive reasons for inferring physicalism’s falsity from the intuition. Regarding the former, they observe that the Mary case divides the knowledge intuition into two claims:
The complete-knowledge claim: before leaving the room, Mary knows everything physical.
The learning claim: upon leaving, she learns something.
Physicalists may deny the knowledge intuition. But the Mary case shows that doing so requires rejecting the complete-knowledge claim or the learning claim, both of which seem plausible.
As Stoljar and Nagasawa explain, this important point is not shown by cases discussed by Broad, Nagel, and others. For example, consider Broad’s “mathematical archangel,” a logically omniscient creature who knows all the physical truths about various chemical compounds. Broad calls these truths ‘mechanistic’ instead of ‘physical’, but the point is the same. On his view, the archangel would know all such truths but still lack phenomenal knowledge concerning, e.g., “the peculiar smell of ammonia”; and he infers that physicalism (“mechanism”) is false. But what if the physicalist denies that the archangel would lack the relevant phenomenal knowledge? We appear to have a standoff. By contrast, if the physicalist claims that in the room Mary knows what it’s like to see colors, he must explain why she seems to acquire this knowledge when she leaves. As Stoljar and Nagasawa say, the Mary case breaks the tie in favor of the knowledge intuition. And as they explain, other illustrations of the intuition that precede Jackson’s have further drawbacks. Mary’s fame is just.
The second of Jackson’s distinctive contributions concerns his inference from the knowledge intuition to physicalism’s falsity. This inference assumes that if physicalism is true then the complete truth about human color vision is a priori deducible from the complete physical truth. Why accept this assumption? Consider what Stoljar and Nagasawa call “the psychophysical conditional”: if P then Q, where P is the complete physical truth and Q is the complete psychological truth. As Jackson conceives of physicalism, this theory entails that the psychophysical conditional is a priori, in which case all truths about color vision would be deducible from P. But why can’t physicalists instead characterize their thesis as a Kripkean a posteriori necessity, akin to “water is H2O”? On this characterization, the psychophysical conditional is metaphysically necessary but not a priori.
In later work, Jackson defends his conception in detail. His argument is complex, but the basic idea is simple enough. In “Postscript,” he reasons as follows. Consider the argument, “H2O covers most of the planet; therefore, water covers most of the planet.” The premise necessitates, but does not a priori entail, the conclusion. But suppose we add the premise, “H2O plays the water role.” In that case, the premises do a priori entail the conclusion. Moral: “a rich enough story about the H2O way things are does enable the a priori deduction of the water way things are” (Jackson 1995, p. 413). Likewise, physicalism entails that “knowing a rich enough story about the physical nature of our world is tantamount to knowing the psychological story about our world” (Jackson 1995, p. 414). But if physicalism is true, P should provide just that: a rich enough story. Thus, physicalism entails the apriority of the psychophysical conditional after all. Jackson’s argument is controversial. But in developing it, he fills an important lacuna in the knowledge argument and thereby improves on earlier versions, as Stoljar and Nagasawa say.
Philosophers have devised several ways to reject the inference from the knowledge intuition to physicalism’s falsity, in addition to challenging the apriority of the psychophysical conditional. Some argue that Mary’s learning consists in acquiring non-propositional knowledge. One version of this view is based on the ability hypothesis, the claim that to know what it’s like is to possess certain abilities, such as the ability to visualize. On this view, Mary’s learning consists in her acquiring abilities rather than learning truths. There are other versions, including the view that upon leaving the room Mary acquires only non-propositional acquaintance knowledge.
Another way to reject the inference to physicalism’s falsity is to argue that Mary’s learning consists in acquiring new ways to represent facts she knew before leaving the room. This view is often combined with an appeal to a posteriori necessity, but it needn’t be: one could argue that while the psychophysical conditional is a priori knowable by those who possess the relevant phenomenal concepts, Mary lacks those concepts before leaving the room.
Philosophers have also devised ways to reject the knowledge intuition. One is to reject the complete-knowledge claim: to argue that not all physical facts about seeing colors can be learned by watching black-and-white lectures. Another is to reject the learning claim: to argue that on reflection Mary doesn’t learn anything when she leaves the room.
All these strategies are well represented in Mary. So are criticisms of them. Advocates of the knowledge argument might complain that negative responses are overrepresented: twelve of the eighteen full-length articles reject the knowledge argument. But this proportion approximates that in the literature. The volume is ideologically balanced.
Of the four new full-length articles, Chalmers’ is by far the best. Since Jackson’s change of mind, the knowledge argument needs a prominent advocate, and Chalmers was born for the role. He formulates the argument in terms of the two-dimensional semantic framework he develops elsewhere (he provides an introduction to the framework in an appendix). This helps to clarify and support the assumptions involved in inferring physicalism’s falsity from the knowledge intuition. He also distinguishes various types of phenomenal concepts, arguing that the type most relevant to the knowledge Mary acquires when leaving the room are “pure”: phenomenal concepts that pick out phenomenal properties in terms of the intrinsic phenomenal natures of these properties, rather than in terms of relations between the properties and external things or acts of ostension. Finally, he levels forceful criticisms against several objections to the knowledge argument.
I didn’t find many valuable new ideas in the other new articles. Van Gulick suggests that the plethora of physicalist criticisms of the knowledge argument indicates that the argument poses little threat to physicalism. This is suspicious. By similar reasoning, the plethora of creationist criticisms of Darwinism would indicate that Darwinism poses little threat to creationism. Hellie suggests that (i) the “core idea behind the knowledge argument” is that “an expressible concept and an inexpressible concept cannot both denote the same entity” and infers that (ii) “the passage through knowledge is largely a detour” (Hellie 2004, p. 350). Both claims are intriguing, though (ii) seems wrong. If knowledge is a detour, then learning is too. But learning is no detour: as we’ve seen, Jackson’s argument is powerful because he formulates it in terms of learning.
Pettit draws an interesting analogy based on akinetopsia, a kind of motion blindness. A person with this condition “sees motion in a jerky series of static images, as if in a stroboscopic light” (Pettit 2004, p. 108). Pettit has us imagine the case of Eva, which is similar to the Mary case except color experiences are replaced with “phenomenal motion.” Eva is confined in a “stroboscopic room,” where she learns the same physical facts that Mary learns; then Eva leaves her room and sees motion in the ordinary way. According to Pettit, Eva learns no new facts; and he concludes that the same is true of Mary. But his analogy is questionable. Few would deny that Mary could deduce some phenomenal truths before leaving the room. For example, even if she’s never seen a black-and-white chessboard, she could presumably deduce what it’s like to see one from a description. Perhaps deducing phenomenal motion is more like deducing what it’s like to see a chessboard than what it’s like to see colors. And if Pettit’s analogy does go through, how should we describe the epistemic progress Eva appears to make upon leaving the room? He suggests that she comes to know in “a practical, nonintellectual mode” facts that she previously knew only in “a purely intellectual way” (Pettit 2004, p. 107). But his elaboration of this familiar idea does little to advance understanding.
In “Mind and Illusion,” Jackson reconsiders the claim that Mary learns new truths when she leaves the room. He argues that this claim derives from a mistaken conception of sensory experience—a conception that he thinks should be replaced with representationalism, the view that phenomenal states are representational states. At the end of the article, he endorses the ability hypothesis. He writes,
Those who resist accounts in terms of ability acquisition tend to say things like ‘Mary acquires a new piece of propositional knowledge, namely, that seeing red is like this’, but for the representationalist there is nothing suitable to be the referent of the demonstrative. We have ended up agreeing with Laurence Nemirow and David Lewis [the authors of the ability-hypothesis strategy] on what happens to Mary on her release. But, for the life of me, I cannot see how we could have known they were right without going via representationalism. (Jackson 2003, p. 439)
“Mind and Illusion” is the last chapter of Mary, but it’s not the last word on the topic. For one thing, it’s unclear why Jackson’s representationalism leads him to embrace the ability hypothesis. Despite his commitments to physicalism and the apriority of the psychophysical conditional, he has other options. For example, instead of explaining Mary’s epistemic progress in terms of newly acquired abilities, he might argue that her “progress” is an illusion; in other words, he might reject the learning claim. Moreover, it’s possible to formulate a representationalist version of the knowledge argument that inherits the force of the original. Or so I argue (Alter, forthcoming); Jackson (forthcoming) disagrees.
There is indeed something about Mary. Our fascination with her continues to enrich our understanding of consciousness and its place in nature, as Mary amply demonstrates.
References
Alter, T. Forthcoming. Does representationalism undermine the knowledge argument? In T. Alter and S. Walter (eds.) Phenomenal Concepts and Phenomenal Knowledge. New York: OUP. Draft at: http://www.as.ua.edu/philos/talter/scholarship.htm.
Broad, C.D. 1925. The Mind and its Place in Nature. London: Routledge and Kegan Paul.
Chalmers, D. 2004. Phenomenal concepts and the knowledge argument. In Mary, pp. 269-98.
Hellie, F. 2004. Inexpressible truths and the allure of the knowledge argument. In Mary, pp. 333-64.
Jackson, F. Forthcoming. The knowledge argument, diaphanousness, representationalism. In T. Alter and S. Walter (eds.) Phenomenal Concepts and Phenomenal Knowledge.
Jackson, F. 2003. Mind and illusion. In A. O’Hear (ed.), Minds and Persons (Cambridge, UK: Cambridge University Press), pp. 251-71. Reprinted in Mary, pp. 421-42.
Jackson, F. 1995. Postscript. In P. Moser and J. Trout (eds.) Contemporary Materialism (London: Routledge), pp. 184-89. Reprinted in Mary, pp. 409-15.
Jackson, F. 1982. Epiphenomenal qualia. Philosophical Quarterly 32, pp. 127-36. Reprinted in Mary, pp. 39-50.
Pettit, P. Motion blindness and the knowledge argument. In Mary, pp. 105-42.
Nagel, T. 1972. What is it like to be a bat? The Philosophical Review 83, pp. 435-50.
Stoljar, D., and Nagasawa, Y. 2004. Introduction to Mary, pp. 1-36.
Van Gulick, R. So many ways of saying no to Mary. In Mary, pp. 365-415.
