Thus far, we have considered some conceptual tensions surrounding consciousness that an antiphysicalist, Liberal Naturalist framework must address-- how do we solve the Boundary Problem, and how viable is panexperientialism? In this chapter, we turn to further tensions that seem to present us with outright paradoxes. Rosenberg's intent here (as before) is not to resolve these paradoxes, but rather to consider the challenges they present and look for clues as to what direction of inquiry would make for fruitful investigation. He asks that we take the same attitude and not attempt to draw strong conclusions or brush the problems off as mere artifacts of cognitive limitations or delusions. By the end of the book, Rosenberg will have presented a detailed outline of his version of Liberal Naturalism, and will be able to use it to address these paradoxes and untangle their seemingly intractable knots without resorting to deflationary tactics. 1. The unity of consciousness The human qualitative field is filled with rich and complex phenomenal events. There is a sense in which these qualia are distinct, but there is another, subtler sense in which they enjoy some sort of coherent unity of presentation. For instance, in the qualitative visual field, we can distinguish the color, shape, and motion of a falling ball as distinct phenomenal properties, but there is also a sense in which these phenomenal properties are bound together and 'overlap' to form a single qualitative object or event. More generally and subtly, we can observe that even phenomenal events occurring in different sensory modalities-- e.g. auditory and visual-- seem to share the same phenomenal space, to be painted on the same canvas, to belong integrally to the same whole. Rosenberg identifies both a challenge and a paradox arising from considerations of the unity of consciousness. The challenge of unity is to give a clear articulation of what the unity of consciousness actually is. We have definite intuitions that the qualitative field is in some sense unified, and these intuitions have even played a part in guiding e.g. the neuroscientific endeavor to frame and then solve the binding problem of percepts. However, it is difficult to give a precise characterization that resonates with our intuitions of exactly what we mean when we say that consciousness is unified. The paradox of unity pits our intuitions about the unity of consciousness against the physical, composite description of the brain. We tend to view the brain, and physical systems in general, as composite systems-- systems that are straightforwardly composed of smaller elements and their relationships to each other. The relevant metaphor here is that of a brick wall, where the wall is the composite system whose existence is determined entirely by its components (the bricks) and their various relationships to each other; in turn, the bricks enjoy an independent existence that does not presuppose the existence of the whole wall. In this way, we view the fundamental particles as composing atoms, atoms as composing organic molecules, organic molecules as composing nerve cells, and so on. At each level, the components of the composite system are separable from the whole-- even if we break the system of relationships that creates the whole, we will still be left with the composite parts. However, the unity condition of consciousness seems to resist such a reductive treatment. Rosenberg argues that it is implausible for a given phenomenal event (e.g. a headache) to exist independently from the entirety of the experiencing subject to which it belongs. Likewise, it is implausible to suppose that the qualitative visual field is composed of 'tiny colored dots' that exist independently of the whole experience. Rather, the elements of our experience seem to already presuppose the existence of the whole experiential manifold, and holistically depend on it to achieve their own existence. Thus, the elements of experience are inseparable from the whole-- were we to break the conditions that support the whole of experience, we would not be left with component qualia floating around disparately. We can state the paradox of unity succinctly, then, as follows: How can a single system be both composite and non-composite? Rosenberg notes that a functionalist treatment seems well suited to describing the unity of consciousness. After all, functional systems have discernible functional entities as elements, but these elements depend on the context of the whole system to achieve their meaning; they cannot be fully specified without reference (be it explicit or implicit) to the entire system of which they are a part. In other words, they cannot be characterized as 'bricks in the wall.' In this way, functional systems capture something of the holistic nature of consciousness in a way that composite physical systems do not. However, while a functionalist perspective may prove invaluable in describing consciousness, it cannot be the whole story for a Liberal Naturalist paradigm. As touched on in chapter 6, a conventional functionalist analysis will suffer to varying degrees from problems of functional teleology, interest relativity, and norms. These are the sorts of things that are created by human observers and imposed upon nature, rather than things that nature itself recognizes and responds to. Perhaps we can work around this problem by defining what it means to be a causal role, and a canonical context for a causal role, in such a way that these do not fall prey to functional teleology, interest relativity, and norms, but rather are objective phenomena to which nature is sensitive. 2. The subjective instant Some sets of phenomenal events in consciousness seem to occur simultaneously. These collections of simultaneous events constitute the subjective instant, or what William James called the specious present. However, these simultaneous phenomenal events correspond with physical brain events that are asynchronous. Even more pressing is the observation that, to the subject of experience, the simultaneity of phenomenal events seems to be a privileged, absolute fact, whereas the laws of special relativity show us that there is no privileged reference frame from which we can decide that a given set of physical events in the brain occur simultaneously in an absolute sense. Succinctly stated, the paradox here is that there seems to be a system to which the laws of relativity both do and do not apply. The temptation here is to write off the subjective instant as an illusion and give complete deference to the relativistic account of spacetime. However, it is not clear that physics has an entirely firm handle on the matter of time and its apparent 'flow.' An appeal is often made to the direction of causation, as implied by the second law of thermodynamics, to account for the apparent directionality of time. This is an attractive proposition, but it is not clear that physics alone affords us a complete account of causation. If the physical facts do not completely fix the facts about causation and the directionality of time, perhaps some light can be shed on the paradox of the subjective instant via a deeper theory of causation and its relationship to the apparent temporal flux. 3. The knowledge paradox If physicalism is false, and if the world is causally closed under physics, it appears as if there is no room for p-consciousness to make a causal contribution to brain events. But clearly, our knowledge claims about p-consciousness (e.g. "I know that I am conscious right now") are driven by physical brain events. If p-consciousness is irrelevant to the causal dynamics of the brain, then, it seems that it can play no role in producing our knowledge claims about it. In short, it seems as if our knowledge claims about p-consciousness should bear no relevance to the phenomenon itself; we should have no way to really know that we are p-conscious, even though we claim that we are. It appears as if the knowledge paradox forces the Liberal Naturalist to be caught on the dual horns of interactionist dualism and epiphenomenalism. We can escape the conundrum of the knowledge paradox if we deny the causal closure of the physical and claim that non-physical p-consciousness really does directly influence the physical dynamics of the brain. The resulting interactionist dualist ontology presents significant further problems, however, and there is no strong evidence that the world is not causally closed under physics. If we reject interactionism, we can bite the bullet and propose that p-consciousness is epiphenomenal on brain events. On this view, p-consciousness is lawfully correlated with brain events, but still does not make any contribution to their causal dynamics. Epiphenomenalism is not much better than interactionism, as it still presents us with significant problems. While knowledge claims about p-consciousness would be true under epiphenomenalism, it seems they would not be justified. Rather, they would be more like lucky coincidences, since there would be no mechanism by which we could attain reasons for making these claims. Our physical brains would cause us to utter that we are p-conscious, and mere serendipity would have it that we were in fact correct. If the laws enforcing the epiphenomenal correlation between brain events and p-conscious events were to somehow be shut off, we would go on (falsely) claiming that we are p-conscious, none the wiser. The knowledge paradox is a deep problem for Liberal Naturalism, and on the surface, it seems as if the Liberal Naturalist is forced to choose between two highly problematic views. But perhaps the paradox does not turn on the nature of p-consciousness so much as it turns on our understanding of causation and its relationship to physics. A deeper theory of causation might allow the Liberal Naturalist to maintain that physicalism is false without being forced into either interactionist dualism or epiphenomenalism. 4. The superfluity of consciousness Suppose that we reject interactionism and embrace epiphenomenalism. The resulting ontology casts p-consciousness as a nomological dangler, a phenomenon that exists despite having no relevance to the causal mesh of the world. Such a view undermines our convictions that nature is parsimonious, and invites speculation that perhaps the world is teeming with phenomena that are superfluous to our scientific understanding of it. This speculation not only does damage to convictions about nature's parsimony, but also undermines any hopes for scientific realism. If nature abounded with entities that are superfluous to our understanding of it, then we could never hope to even approach anything like ontological truth. Our scientific theories would remain useful for predicting the outcomes of experiments, but they would likely not tell us anything about what the world is really like. Occam's razor would become a purely pragmatic consideration rather than a useful metaphysical tool for science and philosophy. The superfluity of consciousness under epiphenomenalism, then, introduces a paradoxical tension between what we take ourselves to know about the world and what we should take ourselves to know about the world. It seems as if we have good reason to think that we know something of the world's ontological nature, but if epiphenomenalism is true, we should not hold any confidence that we do. 5. The grain problem The grain problem arises from considering the incongruence between the structural complexity of phenomenal events in p-consciousness and the structural complexity of their physical, neural correlates. For instance, observe that a uniform patch of color in the qualitative visual field has a simple, homogenous structure, whereas the neural events that correlate with it have a high degree of varying structural complexities and nuances. We cannot inspect a uniform patch of phenomenal color more closely and reveal further layers of structural complexity corresponding to the structural complexities of the correlated neural events. In short, qualia are very coarse-grained with respect to their finer-grained neural correlates. The grain problem is pressing for physicalism, but not necessarily so for Liberal Naturalism, which is not obligated to suppose that the physical is the ultimate basis for the experiential. But we are still left with the question of what does form the basis for experience, and how it does this in such a way as to resolve the grain problem. Once again, functionalism seems a promising candidate. As previously discussed, functional entities derive their meaning from the specific kind of causal role they play in a larger functional context. Importantly, we need not specify lower level structural details in order to define a functional object or its causal role. The only relevant details of the functional specification are the abstract, higher-level patterns of causation that constitute the functional system as a whole, and the causal contributions that each functional component of the system makes to the system as a whole. For instance, we can regard a computer program as a functional system in this way. What essentially defines the computer program is just its abstract functional pattern of information processing. The lower-level structures of the program-- the physical or logical systems that implement it-- are irrelevant to the description of the program itself, and can be abstracted away. It does not matter if we implement a given program on a PC computer or on an abacus, so long as we guarantee that its characteristic high-level patterns of information processing are preserved. In this way, functional systems are encapsulated at their own level of nature. The ontological nature of functional systems, insofar as we view them purely as functional systems, has no finer grain. We can now immediately see a parallel between the coarse-grained nature of functional being and the coarse-grained nature of qualia, a parallel that seems to invite a treatment of the grain problem by way of a functionalist account of p-consciousness. However, we must note again that while an appeal to functionalism may be critically important, it cannot tell the whole story. And, as before, we cannot give the whole answer without a closer analysis of what causation is and how it individuates and stratifies phenomena in nature. Summary Let us take stock of where we are right now. We have considered a number of puzzles and paradoxes surrounding p-consciousness, including the boundary problem, the unity of consciousness, the subjective instant, the knowledge paradox, the superfluity of consciousness, and the grain problem. Each of these deep conceptual problems raises questions about causation in some manner or another. It seems likely, then, that there is some fundamental deficiency in our understanding of causation that is inexorably leading us to systematic confusions about p-consciousness and its relationship with the physical. With this observation, we conclude Part I of the book. In Part II, Rosenberg will turn his focus to causation, critiquing conventional views of causation and constructing his own novel theory. Once Rosenberg's theory of causation is in place, he will come full circle and return better equipped to questions about p-consciousness and its relationship to the physical.