Functionalism and Qualia

The objective of this paper is to defend the non-reductive thesis of phenomenal consciousness. This paper will give an overview of the arguments for the non-reductive explanation of phenomenal consciousness and justify why the reductionist approach is implausible in the context of explaining phenomenal subjective experience. The debate between reductionist and non-reductionist on the project of Demystifying and Mystifying phenomenal consciousness is driven by two fundamental assumptions-1) Reductive-Naturalistic Objectivism, 2) Phenomenal Realism. There are several arguments for the irreducibility of phenomenal (...) consciousness; this paper will focus on the inverted spectrum argument, knowledge argument, and the conceivability argument. (shrink)

Two views on the nature and location of pain are usually contrasted. According to the first, experientialism, pain is essentially an experience, and its bodily location is illusory. According to the second, perceptualism or representationalism, pain is a perceptual or representational state, and its location is to be traced to the part of the body in which pain is felt. Against this second view, the cases of phantom, referred and chronic pain have been marshalled: all these cases apparently show that (...) one can be in pain while not having anything wrong in her body. Pain bodily location, then, would be illusory. I this paper I shall defend the representational thesis by presenting an argument against experientialism while conceding that the appearance / reality distinction collapses. A crucial role in such identification is played by deictics. In reporting that we feel pain here, the deictic directly refers to the bodily part as coinciding with the part as represented. So, pain location is not illusory. The upshot is that the body location is part and parcel of the representational content of pain states, a representation built up from the body map. (shrink)

Very plausibly, nothing can be a genuine computing system unless it meets an input-sensitivity requirement. Otherwise all sorts of objects, such as rocks or pails of water, can count as performing computations, even such as might suffice for mentality—thus threatening computationalism about the mind with panpsychism. Maudlin in J Philos 86:407–432, ( 1989 ) and Bishop ( 2002a , b ) have argued, however, that such a requirement creates difficulties for computationalism about conscious experience, putting it in conflict with the (...) very intuitive thesis that conscious experience supervenes on physical activity. Klein in Synthese 165:141–153, ( 2008 ) proposes a way for computationalists about experience to avoid panpsychism while still respecting the supervenience of experience on activity. I argue that his attempt to save computational theories of experience from Maudlin’s and Bishop’s critique fails. (shrink)

And supposing there were a machine, so constructed as to think, feel, and have perception, it might be conceived as increased in size, while keeping the same proportions, so that one might go into it as into a mill. That being so, we should, on examining its interior, find only parts which work on one another, and never anything by which to explain a perception.Gottlieb Leibniz, The Mondadology, Section 17Functionalism, as it is currently understood, is the view that each type (...) of mental state is identical with a state that is a causal consequent of certain kinds of inputs and other mental states and which, in turn, causally brings about certain kinds of outputs and other mental states. (shrink)

I draw attention to an ambiguity of the expression ‘phenomenal consciousness’ that is an avoidable yet persistent source of conceptual confusion among consciousness scientists. The ambiguity is between what I call phenomenality and what I call conscious states, where the former denotes an abstract property and the latter denotes a phenomenon or class of its instances. Since sentences featuring these two terms have different semantic properties, it is possible to equivocate over the term ‘consciousness’. It is also possible to fail (...) to distinguish between statements that are true about conscious states in virtue of their phenomenality, and statements that are true in virtue of other properties of conscious states. I review empirically informed arguments by scientists Bernard Balleine and Anthony Dickinson, Stevan Harnad, and Jeffrey Alan Gray, arguing that each of them makes errors based on the ambiguity. I conclude with some tentative suggestions for avoiding further confusion about the ambiguity. (shrink)

This contribution examines two radically different explanations of our phenomenal intuitions, one reductive and one strongly non-reductive, and identifies two germane ideas that could benefit many other theories of consciousness. Firstly, the ability of sophisticated agent architectures with a purely physical implementation to support certain functional forms of qualia or proto-qualia appears to entail the possibility of machine consciousness with qualia, not only for reductive theories but also for the nonreductive ones that regard consciousness as ubiquitous in Nature. Secondly, analysis (...) of introspective psychological material seems to hint that, under the threshold of our ordinary waking awareness, there exist further ‘submerged’ or ‘subliminal’ layers of consciousness which constitute a hidden foundation and support and another source of our phenomenal intuitions. These ‘submerged’ layers might help explain certain puzzling phenomena concerning subliminal perception, such as the apparently ‘unconscious’ multisensory integration and learning of subliminal stimuli. (shrink)

Some philosophers have conflated functionalism and computationalism. I reconstruct how this came about and uncover two assumptions that made the conflation possible. They are the assumptions that (i) psychological functional analyses are computational descriptions and (ii) everything may be described as performing computations. I argue that, if we want to improve our understanding of both the metaphysics of mental states and the functional relations between them, we should reject these assumptions.

A solution to the “hard problem” requires taking the point of view of the organism and its sub- agents. The organism constructs phenomenality through acts of fiat, much as we create meaning in language, through the use of symbols that are assigned meaning in the context of an embodied evolutionary history. Phenomenality is a virtual representation, made to itself by an executive agent (the conscious self), which is tasked with monitoring the state of the organism and its environment, planning future (...) action, and coordinating various sub-agencies. Consciousness is not epiphenomenal and serves a function for higher organisms that is distinct from unconscious processing. While a strictly scientific solution to the hard problem is not possible for a science that excludes the subjectivity it seeks to explain, there is hope to at least informally bridge the explanatory gulf between mind and matter. (shrink)

The paper is a critical comment on D. Hoffman. The Scrambling Theorem: A simple proof of the logical possibility of spectrum inversion. Consciousness and Cognition, 2006, 15, 31–45.

Neurological syndromes in which consciousness seems to malfunction, such as temporal lobe epilepsy, visual scotomas, Charles Bonnet syndrome, and synesthesia offer valuable clues about the normal functions of consciousness and ‘qualia’. An investigation into these syndromes reveals, we argue, that qualia are different from other brain states in that they possess three functional characteristics, which we state in the form of ‘three laws of qualia’. First, they are irrevocable: I cannot simply decide to start seeing the sunset as green, or (...) feel pain as if it were an itch; second, qualia do not always produce the same behaviour: given a set of qualia, we can choose from a potentially infinite set of possible behaviours to execute; and third, qualia endure in short-term memory, as opposed to non-conscious brain states involved in the on-line guidance of behaviour in real time. We suggest that qualia have evolved these and other attributes because of their role in facilitating non-automatic, decision-based action. We also suggest that the apparent epistemic barrier to knowing what qualia another person is experiencing can be overcome by using a ‘bridge’ of neurons; and we offer a hypothesis about the relation between qualia and one's sense of self. (shrink)

Within psychology and the brain sciences, the study of consciousness and its relation to human information processing is once more a focus for productive research. However, some ancient puzzles about the nature of consciousness appear to be resistant to current empirical investigations, suggesting the need for a fundamentally different approach. In Velmans I have argued that functional accounts of the mind do not `contain' consciousness within their workings. Investigations of information processing are not investigations of consciousness as such. Given this, (...) first-person investigations of experience need to be related nonreductively to third-person investigations of processing. For example, conscious contents may be related to neural/physical representations via a dual-aspect theory of information. Chalmers arrives at similar conclusions. But there are also theoretical differences. Unlike Chalmers I argue for the use of neutral information processing language for functional accounts rather than the term `awareness'. I do not agree that functionalctional equivalence cannot be extricated from phenomenal equivalence, and suggest a hypothetical experiment for doing so - using a cortical implant for blindsight. I argue that not all information has phenomenal accompaniments, and introduce a different form of dual-aspect theory involving `psychological complementarity'. I also suggest that the hard problem posed by `qualia' has its origin in a misdescription of everyday experience implicit in dualism. (shrink)

This book addresses the fascinating cross-disciplinary field of quantum information theory applied to the study of brain function. It offers a self-study guide to probe the problems of consciousness, including a concise but rigorous introduction to classical and quantum information theory, theoretical neuroscience, and philosophy of the mind. It aims to address long-standing problems related to consciousness within the framework of modern theoretical physics in a comprehensible manner that elucidates the nature of the mind-body relationship. The reader also gains an (...) overview of methods for constructing and testing quantum informational theories of consciousness. (shrink)

This paper examines the explanatory gap account. The key notions for its proper understanding are analysed. In particular, the analysis is concerned with the role of “thick” and “thin” modes of presentation and “thick” and “thin” concepts which are relevant for the notions of “thick” and “thin” conceivability, and to that effect relevant for the gappy and non-gappy identities. The last section of the paper discusses the issue of the intelligibility of explanations. One of the conclusions is that the explanatory (...) gap account only succeeds in establishing the epistemic gap. The claim that psychophysical identity is not intelligibly explicable, and thus opens the explanatory gap, would require an indepen- dent argument which would prove that intelligible explanations stem only from conceptual analysis. This, I argue, is not the case. (shrink)

Following an on-line dialogue with Dennett (Velmans, 2001) this paper examines the similarities and differences between heterophenomenology (HP) and critical phenomenology (CP), two competing accounts of the way that conscious phenomenology should be, and normally is incorporated into psychology and related sciences. Dennett’s heterophenomenology includes subjective reports of conscious experiences, but according to Dennett, first person conscious phenomena in the form of “qualia” such as hardness, redness, itchiness etc. have no real existence. Consequently, subjective reports about such qualia should be (...) understood as prescientific attempts to make sense of brain functioning that can be entirely understood in third person terms. I trace the history of this position in behaviourism (Watson, Skinner and Ryle) and early forms of physicalism and functionalism (Armstrong), and summarise some of the difficulties of this view. Critical phenomenology also includes a conventional, third person, scientific investigation of brain and behaviour that includes subjects’ reports of what they experience. CP is also cautious about the accuracy or completeness of subjective reports. However, unlike HP, CP does not assume that subjects are necessarily deluded about their experiences or doubt that these experiences can have real qualities that can, in principle, be described. Such experienced qualities cannot be exhaustively reduced to third-person accounts of brain and behaviour. CP is also reflexive, in it assumes experimenters to have first-person experiences that they can describe much as their subjects do. And crucially, experimenter’s third-person reports of others are based, in the first instance, on their own first-person experiences. CP is commonplace in psychological science, and given that it conforms both to scientific practice and common sense, I argue that there is little to recommend HP other than an attempt to shore up a counterintuitive, reductive philosophy of mind. (shrink)

Les théories de l’évolution de la conscience sont étroitement liées aux théories de la distribution de la conscience qui vont des approches considérant que seulement l’homme a une conscience jusqu’aux approches considérant que toute matière possède une conscience en quelque sorte. De manière générale, on peut distinguer les théories de la discontinuité des théories de la continuité. Les théories de la discontinuité considèrent que la conscience est apparue seulement une fois que les formes matérielles ont atteint un certain degré d’évolution (...) mais proposent des critères différents lorsqu’il s’agit de déterminer le degré en question. Les théories de la continuité soutiennent que, dans une certaine forme primaire, la conscience accompagne toujours la matière et tandis que celle-ci a évolué vers la forme, la complexité de la conscience a co-évolué avec elle, vers par exemple des formes que nous reconnaissons actuellement chez les êtres humains. Etant donnée notre connaissance limitée des conditions suffisantes et nécessaires à la présence de la conscience chez les êtres humains, toutes les options restent ouvertes. Tout compte fait, la théorie de la continuité paraît plus élégante que la théorie de la discontinuité. (shrink)

An evaluation of the strengths, weaknesses, and originality of Chalmer's book.

Physicalists commonly argue that conscious experiences are nothing more than states of the brain, and that conscious qualia are observer-independent, physical properties of the external world. Although this assumes the 'mantle of science,' it routinely ignores the findings of science, for example in sensory physiology, perception, psychophysics, neuropsychology and comparative psychology. Consequently, although physicalism aims to naturalise consciousness, it gives an unnatural account of it. It is possible, however, to develop a natural, nonreductive, reflexive model of how consciousness relates to (...) the brain and the physical world. This paper introduces such a model and how it construes the nature of conscious experience. Within this model the physical world as perceived is viewed as part of conscious experience not apart from it. While in everyday life we treat this phenomenal world as if it is the "physical world", it is really just one biologically useful representation of what the world is like that may differ in many respects from the world described by physics. How the world as perceived relates to the world as described by physics can be investigated by normal science . This model of consciousness appears to be consistent with both third-person evidence of how the brain works and with first-person evidence of what it is like to have a given experience. According to the reflexive model, conscious experiences are really how they seem. (shrink)

Definitions of consciousness need to be sufficiently broad to include all examples of conscious states and sufficiently narrow to exclude entities, events and processes that are not conscious. Unfortunately, deviations from these simple principles are common in modern consciousness studies, with consequent confusion and internal division in the field. The present paper gives example of ways in which definitions of consciousness can be either too broad or too narrow. It also discusses some of the main ways in which pre-existing theoretical (...) commitments (about the nature of consciousness, mind and world) have intruded into definitions. Similar problems can arise in the way a “conscious process” is defined, potentially obscuring the way that conscious phenomenology actually relates to its neural correlates and antecedent causes in the brain, body and external world. Once a definition of “consciousness” is firmly grounded in its phenomenology, investigations of its ontology and its relationships to entities, events and processes that are not conscious can begin, and this may in time transmute the meaning (or sense) of the term. As our scientific understanding of these relationships deepen, our understanding of what consciousness is will also deepen. A similar transmutation of meaning (with growth of knowledge) occurs with basic terms in physics such as "energy", and "time.". (shrink)

This paper replies to the first 36 commentaries on my target article on “Is human information processing conscious?” (Behavioral and Brain Sciences,1991, pp.651-669). The target article focused largely on experimental studies of how consciousness relates to human information processing, tracing their relation from input through to output, while discussion of the implications of the findings both for cognitive psychology and philosophy of mind was relatively brief. The commentaries reversed this emphasis, and so, correspondingly, did the reply. The sequence of topics (...) in the reply roughly follows that of the target article. The discussion begins with a reconsideration of the details of the empirical findings, whether they can be extrapolated to non-laboratory settings, and the extent to which one can rely on their use of subjective reports. This is followed by an in-depth discussion of what is meant by “conscious processing” and of how phenomenal consciousness relates to attentional processing. We then turn to broader philosophical and theoretical issues. I point out some of the reasons why I do not support epiphenomenalism, dualist-interactionism, or reductionism, and elaborate on how first- and third-person views of the mind can be regarded as complementary and mutually irreducible. I suggest how the relation of conscious experiences to their neural correlates can be understood in terms of a dual-aspect theory of information,and how this might be used to resolve some of the paradoxes surrounding the causal interactions of consciousness and brain. I also suggest that, viewed from a first-person perspective, consciousness gives purpose to existence, which allows a different way of viewing its role in evolution. (shrink)

Investigations of the function of consciousness in human information processing have focused mainly on two questions: (1) where does consciousness enter into the information processing sequence and (2) how does conscious processing differ from preconscious and unconscious processing. Input analysis is thought to be initially "preconscious," "pre-attentive," fast, involuntary, and automatic. This is followed by "conscious," "focal-attentive" analysis which is relatively slow, voluntary, and flexible. It is thought that simple, familiar stimuli can be identified preconsciously, but conscious processing is needed (...) to identify complex, novel stimuli. Conscious processing has also been thought to be necessary for choice, learning and memory, and the organization of complex, novel responses, particularly those requiring planning, reflection, or creativity. (shrink)

The hermeneutic tradition divides /physical/ discourse, which takes an 'exterior' point of view in /describing/ its subject-matter, from /mental/ discourse, which takes an 'interior' point of view in /expressing/ its subject-matter: a 'metapsychological dualist' or 'metadualist' approach. The analytic tradition, in its attachment to truth-logic and consequently the 'unity of science', is 'metamonist', and thinks all discourse takes the 'exterior' viewpoint: the 'bump in the rug' moves to the disunification of mind into the functional and (big-'C') Consciousness. Assuming the hermeneuts (...) are correct, the literature's twisty path---from Place and Smart's confused metamonist responses to Ryle's crypto-metadualist /Concept of Mind/ to contemporary metamonist 'phenomenal intentionality'---emerges as an attempt to stabilize theory on a fundamentally wobbly platform. (shrink)

Palmer's strategy of saving functionalism by constraining spectrum inversions cannot succeed because (1) there remain many nontrivial transformations not ruled out by Palmer's constraints, and (2) the constraints involved are due to the contingent makeup of our visual systems, and are therefore not available for use by functionalists.

This paper suggests that it is largely a want of notional distinctions which fosters the “explanatory gap” that has beset the study of consciousness since T. Nagel’s revival of the topic. Modifying Ned Block’s controversial claim that we should countenance a “phenomenal-consciousness” which exists in its own right, we argue that there is a way to recuperate the intuitions he appeals to without engaging in an onerous reification of the facet in question. By renewing with the full type/token/tone trichotomy developed (...) by C. S. Peirce, we think the distinctness Block calls attention to can be seen as stemming not from any separate module lurking within the mind, but rather from our ability to prescind qualities from occurrences. (shrink)

In this dissertation, I defend the thesis that qualitative mental states known as qualia are identical to physical properties. In Chapter 1, I argue that qualia have a functional role in the world, and that is to facilitate non-automatic mental processes. In Chapter 2, I demonstrate how non-reductive accounts of the mind fail. In Chapter 3, I demonstrate how my reductive account fares better than similar accounts with respect to common and contemporary objections. In Chapter 4, I address arguments against (...) any view like mine which seeks to understand qualia in a physicalistic framework. (shrink)

[opening paragraph]: It is easy to conceptualize a problem in a way that prevents a solution. If the conceptualization is entrenched in one's culture or profession, it may appear unalterable. But there is so much precedent for the discovery of fruitful reconceptualizations that in the case of most philosophical and scientific puzzles it is probably irrational ever to give up trying. The notion of qualia, understood as phenomenal properties of sensations that can exist as objects of experience for a conscious (...) subject, is too recent in origin and too specialized in usage to warrant concluding that qualia cannot be understood in terms of physical processes. Humphrey offers an analysis of qualitative mental states that purportedly renders them commensurate with brain states, allowing them to be described in terms of the same dimensions. If his attempt is successful the conceptual gap between mind and body could be closed. Is it successful? (shrink)

Jackson has ellaborated an argument to show that our experiences or qualitative states gather information which cannot be obtained in any other way. Functionalists reject in many ways that experience may bring new information. The point of this paper is to argue that, if func-tionalism is right, if experiences or "qualia" are not informative, then functionalism cannot report about them. The functionalist criticism of Jackson's argument makes it impossible for any functionalist theory to know experience.

In “Absent Qualia and the Mind-Body Problem,” Michael Tye (2006) presents an argument by which he claims to show the inconceivability of beings that are functionally equivalent to phenomenally conscious beings but lack any qualia. On that basis, he concludes that qualia can be fully defined in functional terms. The argument does not suffice to establish the claimed results. In particular it does not show that such absent qualia cases are inconceivable. Tye’s argument relies on a principle P according to (...) which the exchange of isomorphic states between functionally equivalent systems will preserve their equivalence. If they were functionally equivalent before the exchange, they will also be so after. Consideration of the contextual nature of realization shows that Principle P is not a general truth as Tye claims, and his argument against the possibility of absent qualia thus fails. (shrink)

I examine the computational functionalist account of mental states presupposed in the field of artificial intelligence , paying particular attention to their inherently subjective character. I begin by discussing the differences between computational functionalism and other forms of functionalism. In Chapter II, I critically examine several criteria proposed by AI researchers for determining when mental states can be attributed to a computer. I then defend John Searle's "Chinese Room" argument against computational functionalism by arguing that an intentional system must be (...) able to understand a language, and genuine understanding of language requires qualitative experience. In Chapter III, I argue that computational functionalism is inadequate for qualitative states, and that because of this, it is inadequate for intentional states. My argument is based on a holistic account of intentional states, together with the notion that there are many intentional states, such as qualitative beliefs, that one can have only if one has certain qualitative states. Finally, in Chapter IV, I develop a version of the property objection to both computational functionalism and the token-identity theory, based on the phenomenon of first-person authority. This argument involves me in an extended defense of the view that de re attitudes are not problematic. I also defend the "argument from knowledge" advanced by Thomas Nagel and Frank Jackson, an argument that applies to materialism as well as to computational functionalism. (shrink)

The contemporary mind-body problem can be seen as a challenge for materialism to provide an account of what I call mental content. The contents of mental states are properties of one of two sorts: intentional or qualitative. The latter of these is the focus of this work, as I provide and defend a functionalist account of "qualia." ;In the first chapter, I defend materialism in two ways. First, I explain its overall plausibility; second, I expose the insuperable difficulties with several (...) forms of dualism. Together, these make the case for materialism more than compelling. Nonetheless, in the second chapter I argue against accepting four different versions of materialism: behaviorism, the identity theory, eliminative materialism, and anomalous monism. ;This sets the stage for a discussion of functionalism, the doctrine that mental states are abstract causal states defined in terms of their relations to an organism's inputs, outputs, and other inner states. In the third chapter, I show that functionalist theories can avoid the difficulites of earlier forms of materialism, while capturing their correct insights. I distinguish four different versions of the view, and argue in favor of accepting homuncular functionalism. This type of functionalism fits the best with recent work in the cognitive sciences, and I believe provides us with the most plausible materialist account of qualia. ;The final two chapters are a detailed defense of functionalism against three objections designed to show that functionalist theories of the mind leave out the qualitative aspects of experience. I conclude that the objections fail, and further suggest a way of explaining qualia in terms of information transfer which occurs at the sub-personal level. (shrink)

Functionalism about qualia is the view that qualia---the qualitative character---of a mental state are determined by functional organization. The dissertation argues for weak functionalism about qualia, a view that is distinguished from strong functionalism about qualia. While strong functionalism claims that qualia are determined by functional organization alone, weak functionalism leaves open the possibility that the occurrence of mental states with qualia depends partly on nonfunctional properties such as specific physical properties or nonphysical properties. The difference between strong functionalism and (...) weak functionalism is highlighted by one of the so called qualia centered objections to functionalism, viz., the absent qualia objection. The absent qualia objection claims that two states could be functionally identical even though only one of the states has qualia. The objection turns out to deny the truth of strong functionalism specifically. Attempts to refute the objection are shown to fail. Weak functionalism about qualia is not touched by the absent qualia objection exactly because of the weakness of the view. The inverted qualia objection---the other one of the absent qualia objections---is also examined. The objection claims that two mental states could be functionally identical even though their qualia could be inverted relative to each other. The objection is shown to fail. ;In the course of the argument for weak functionalism, three competitors to functionalism are rejected: type-physicalism about qualia, dualism about qualia, and wide representationalism about qualia. A discussion of representationalism about qualia distinguishes two versions of the view: wide representationalism and narrow representationalism. Narrow representationalism about qualia is shown to be compatible with functionalism about qualia. Only the wide version of the view is incompatible with functionalism about qualia. ;Although the dissertation argues for weak functionalism it does not claim that strong functionalism is false. The intention is merely to show that all the attempts to prove strong functionalism true fail. The failure of the attempts is compatible with the possibility that strong functionalism is true---even if the view cannot be shown to be true. (shrink)

The aim of this dissertation is to rebut a formidable objection to all fuctionalist theories of the mental. The objection is widely known as "the Qualia Objection." It contends that functionalism is false because it cannot give an adequate account of the non-conceptual, non-cognitive, phenomen.

In his recent article "The Computational Model of the Mind and Philosophical Functionalism," Richard Double argues that there are some fairly forceful a priori arguments showing that Philosophical Functionalism cannot provide adequate explanations for phenomenal states, the nonphenomenal conscious states of common sense, and the theoretical states of cognitive psychology and linquistics. In this paper it is argued that none of Double's arguments are successful.

Latash & Anson's intention to describe only the regularities of motor behavior is compromised by the homunculus paradigm. Although we concur on the need to redefine in atypical populations, we contend that this enterprise requires a process based functionalism. We argue for accommodating movement control and perceptual processes with physical and task constraints in a natural setting.

Ned Block’s Chinese Nation Argument is offered as a counterexample to Turing-machine functionalism. According to that argument, one billion Chinese could be organized to instantiate Turing-machine descriptions of mental states. Since we wouldn’t want to impute qualia to such an organized population, functionalism cannot account for the qualitative character of mental states like pain. Paul Churchland and Patricia Churchland have challenged that argument by trying to show that an adequate representation of the complexity of mind requires at least 10 30,000,000 (...) homunculi. As such a large collection of Chinese is beyond comprehension, the intuitive force of Block’s example would be undercut. I argue that Churchland and Church land erroneously assume that every possible input-state combination in the human Turing-machine table must be assigned a homunculus. I attempt to restore the intuitive force of Block’s thought experiment by pointing to a way to simulate the human mind that does not require any such staggering number of homunculi. (shrink)

Frank Jackson’s famous Knowledge Argument moves from the premise that complete physical knowledge about experiences is not complete knowledge about experiences to the falsity of physicalism. Some physicalists (e.g., John Perry) have countered by arguing that what Jackson’s Mary, the perfect scientist who acquires all physical knowledge about experiencing red while being locked in a monochromatic room, lacks before experiencing red is merely a piece of recognitional knowledge of an identity, and that since lacking a piece of recognitional knowledge of (...) an identity does not entail lacking any pieces of knowledge of worldly facts, physicalism is safe. I will argue that what Mary lacks in her room is not merely a piece of recognitional knowledge of an identity and that some physicalists have failed to see this because of a failure to appreciate that Mary’s epistemic progress when she first experiences red has two different stages. While the second epistemic stage can perhaps be plausibly considered as acquiring merely a piece of recognitional knowledge of an identity, there is good reason to think that the first epistemic stage cannot be thus considered. (shrink)