Bertrand Russell was one of the greatest logicians since Aristotle, and one of the most important philosophers of the past two hundred years. As we approach the 125th anniversary of the Nobel laureate's birth, his works continue to spark debate, resounding with unmatched timeliness and power. The Problems of Philosophy, one of the most popular works in Russell's prolific collection of writings, has become core reading in philosophy. Clear and accessible, this little book is an intelligible and stimulating guide to (...) those problems of philosophy which often mistakenly lead to its status as too lofty and abstruse for the lay mind. Focusing on problems he believes will provoke positive and constructive discussion, Russell concentrates on knowledge rather than metaphysics, steering the reader through his famous 1910 distinction between "knowledge by acquaintance and knowledge by description," and introducing important theories of Descartes, Kant, Hegel, Hume, Locke, Plato, and others to lay the foundation for philosophical inquiry by general readers and scholars alike.With a new introduction by John Perry, this valuable work is a perfect introduction to the field and will continue to stimulate philosophical discussion as it has done for nearly forty years. (shrink)

A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form (...) a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)

Most early studies of consciousness have focused on human subjects. This is understandable, given that humans are capable of reporting accurately the events they experience through language or by way of other kinds of voluntary response. As researchers turn their attention to other animals, “accurate report” methodologies become increasingly difficult to apply. Alternative strategies for amassing evidence for consciousness in non-human species include searching for evolutionary homologies in anatomical substrates and measurement of physiological correlates of conscious states. In addition, creative (...) means must be developed for eliciting behaviors consistent with consciousness. In this paper, we explore whether necessary conditions for consciousness can be established for species as disparate as birds and cephalopods. We conclude that a strong case can be made for avian species and that the case for cephalopods remains open. Nonetheless, a consistent effort should yield new means for interpreting animal behavior. (shrink)

In _Matter and Consciousness_, Paul Churchland presents a concise and contemporary overview of the philosophical issues surrounding the mind and explains the main theories and philosophical positions that have been proposed to solve them. Making the case for the relevance of theoretical and experimental results in neuroscience, cognitive science, and artificial intelligence for the philosophy of mind, Churchland reviews current developments in the cognitive sciences and offers a clear and accessible account of the connections to philosophy of mind. For this (...) third edition, the text has been updated and revised throughout. The changes range from references to the iPhone's "Siri" to expanded discussions of the work of such contemporary philosophers as David Chalmers, John Searle, and Thomas Nagel. Churchland describes new research in evolution, genetics, and visual neuroscience, among other areas, arguing that the philosophical significance of these new findings lies in the support they tend to give to the reductive and eliminative versions of materialism. Matter and Consciousness, written by the most distinguished theorist and commentator in the field, offers an authoritative summary and sourcebook for issues in philosophy of mind. It is suitable for use as an introductory undergraduate text. (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)

In 1995, in my book, Ten Problems of Consciousness, I proposed a version of the theory of phenomenal consciousness now known as representationalism. The present book, in part, consists of a further development of that theory along with replies to common objections. It is also concerned with two prominent challenges for any reductive theory of consciousness: the explanatory gap and the knowledge argument. In addition, it connects representationalism with two more general issues: the nature of color and the location of (...) the phylogenetic dividing line between those creatures that are phenomenally conscious and those that are not. (shrink)

Around 540 million years ago there was a sudden, dramatic adaptive radiation known as the Cambrian Explosion. This event marked the origin of almost all of the phyla (major lineages characterized by fundamental body plans) of animals that would ever live on earth, as well the appearance of many notable features such as rigid skeletons and other hard parts, complex jointed appendages, eyes, and brains. This radical evolutionary event has been a major puzzle for evolutionary biologists since Darwin, and while (...) our understanding of it has recently improved with new fossil finds, richer molecular phylogenies, and better grasp of ecological, evolutionary, and developmental processes generally, unanswered questions remain. In this paper I argue that a basic cognitive toolkit for embodied, object-oriented, spatial cognition (what I call Basic Cognitive Embodiment) is a practical necessity for control of a large, mobile, complexly articulated body in space. This hypothesis allows us to relate the complexification of animal bodies to the complexification of perception, cognition and behavior in a way that can help to fill in gaps in our emerging picture of the Cambrian Explosion, as well as shed light on the deep evolutionary origins of the mind. (shrink)

This book collects twelve original articles, arranged in three sections, plus an introduction.

" In Being No One, Metzinger, a German philosopher, draws strongly on neuroscientific research to present a representationalist and functional analysis of...

The typical empirical approach to studying consciousness holds that we can only observe the neural correlates of experiences, not the experiences themselves. In this paper we argue, in contrast, that experiences are concrete physical phenomena that can causally interact with other phenomena, including observers. Hence, experiences can be observed and scientifically modelled. We propose that the epistemic gap between an experience and a scientific model of its neural mechanisms stems from the fact that the model is merely a theoretical construct (...) based on observations, and distinct from the concrete phenomenon it models, namely the experience itself. In this sense, there is a gap between any natural phenomenon and its scientific model. On this approach, a neuroscientific theory of the constitutive mechanisms of an experience is literally a model of the subjective experience itself. We argue that this metatheoretical framework provides a solid basis for the empirical study of consciousness. (shrink)

One way to express the most persistent part of the mind-body problem is to say that there is an “explanatory gap” between the physical and the mental. The gap is not usually taken to apply to all of the mental, but to subjective experience, the mind’s “qualitative” features, or what is now referred to as “phenomenal consciousness.” The “gap” formulation is due to Joseph Levine. He acknowledged the appeal of intuitions of separability between physical facts, of any kind we can (...) envisage, and this aspect of our mental lives. Subjective experience seems not to be the sort of thing that is just the physical under another guise. The immediate focus of Levine’s discussion was a family of arguments due to Saul Kripke. Kripke argued that some influential claims of mind-body identity could not be, as materialists claimed, contingent. If these identities are real then they are necessary. But we can clearly conceive that the mental and physical could come apart—an intuition that “identity theorists” conceded. Given that the identity is necessarily present if present at all, from the fact it is not necessary we can see it is absent. Kripke concluded that physicalism is false. Levine wanted to resist this. (shrink)

While life in general can be explained by the mechanisms of physics, chemistry and biology, to many scientists and philosophers it appears that when it comes to explaining consciousness, there is what the philosopher Joseph Levine called an “explanatory gap” between the physical brain and subjective experiences. Here we deduce the living and neural features behind primary consciousness within a naturalistic biological framework, identify which animal taxa have these features (the vertebrates, arthropods, and cephalopod molluscs), then reconstruct when consciousness first (...) evolved and consider its adaptive value. We theorize that consciousness is based on all the complex system features of life, plus the even more complex features of elaborate brains. We argue that the main reason why the explanatory gap between the brain and experience has been so refractory to scientific explanation is that it arises from both life and from varied and diverse brains and brain regions, so bridging the gap requires a complex, multifactorial account that includes the great diversity of consciousness, its personal nature that stems from embodied life, and the special neural features that make consciousness unique in nature. (shrink)

In light of the phenomenon of multiple realizability, many philosophers wanted to preserve the mind-brain identity theory by resorting to a “narrow reductive strategy” whereby one (a) finds mental properties which are (b) sufficiently narrow to avoid the phenomenon of multiple realization, while being (c) explanatorily adequate to the demands of psychological theorizing. That is, one replaces the conception of a mental property as more general feature of cognitive systems with many less general properties, for example, replacing the conception of (...) pain as a general property across different species with a number of species-specific kinds of pain. Many critics focused on (c), arguing that species-specific properties are not explanatorily adequate because they do not capture what is common in pain across species. In this paper I focused on (b). I argued that if one carries the narrow reductive strategy out in such a way to avoid all multiple realizability that occurs within a species, for example, accommodating individual differences by postulating a more narrow pain-relative-to-an-individual-at-a-time, then the result is for all intents and purposes a claim about tokens and not types or properties at all (the position is now about individuals having properties at times, a structured token event). I also added an important point about explanation, viz., that properties-relative-to-individuals-at-times would not serve the explanatory goals of science by failing to generalize to other individuals. (shrink)

Most early studies of consciousness have focused on human subjects. This is understandable, given that humans are capable of reporting accurately the events they experience through language or by way of other kinds of voluntary response. As researchers turn their attention to other animals, “accurate report” methodologies become increasingly difficult to apply. Alternative strategies for amassing evidence for consciousness in non-human species include searching for evolutionary homologies in anatomical substrates and measurement of physiological correlates of conscious states. In addition, creative (...) means must be developed for eliciting behaviors consistent with consciousness. In this paper, we explore whether necessary conditions for consciousness can be established for species as disparate as birds and cephalopods. We conclude that a strong case can be made for avian species and that the case for cephalopods remains open. Nonetheless, a consistent effort should yield new means for interpreting animal behavior. (shrink)

Brains, it has recently been argued, are essentially prediction machines. They are bundles of cells that support perception and action by constantly attempting to match incoming sensory inputs with top-down expectations or predictions. This is achieved using a hierarchical generative model that aims to minimize prediction error within a bidirectional cascade of cortical processing. Such accounts offer a unifying model of perception and action, illuminate the functional role of attention, and may neatly capture the special contribution of cortical processing to (...) adaptive success. This target article critically examines this approach, concluding that it offers the best clue yet to the shape of a unified science of mind and action. Sections 1 and 2 lay out the key elements and implications of the approach. Section 3 explores a variety of pitfalls and challenges, spanning the evidential, the methodological, and the more properly conceptual. The paper ends (sections 4 and 5) by asking how such approaches might impact our more general vision of mind, experience, and agency. (shrink)

This volume introduces readers to emergence theory, outlines the major arguments in its defence, and summarizes the most powerful objections against it. It provides the clearest explication yet of this exciting new theory of science, which challenges the reductionist approach by proposing the continuous emergence of novel phenomena.

Characterizing the first- and third-person perspectives is essential to the study of consciousness, yet we lack a rigorous definition of or criteria for these two perspectives. Our intuitive understanding of how personal pronouns help to specify the perspectives gives rise to mutually exclusive notions of the first-person perspective. This contradiction thwarts our progress in studying consciousness. We can resolve the current ambiguity of the first-person perspective by introducing a new distinction between the first-person and third-person perspectives, based on two modes (...) of consciousness: reflective and non-reflective. The purpose of this paper is to explain this new proposal, to elucidate the grounds for it, and to briefly suggest benefits from its use. (shrink)

Higher‐order theories purport to account for the conscious character of such states in terms of higher‐order representations. This chapter focuses on three classes of higher‐order theory of phenomenal consciousness, including inner‐sense theory, actualist higher‐order thought theory, and dispositionalist higher‐order thought theory. All three of these higher‐order theories purport to offer reductive explanations of phenomenal consciousness. Inner‐sense theory has important positive virtues, but faces problems; whereas actualist higher‐order thought theory avoids those problems, but at the cost of losing the positive virtues. (...) Actualist higher‐order thought theory has the advantage that no special organs or mechanisms need to be postulated. Dispositionalist higher‐order thought theory claims to split the difference, providing an account that has all of the advantages of inner‐sense theory with none of the flaws. The success of dispositionalist higher‐order thought theory is premised upon the existence of dual analog contents. (shrink)

Often when there is no attention to an object, there is no conscious perception of it either, leading some to conclude that conscious perception is an attentional phenomenon. There is a well-known perceptual phenomenon—visuo-spatial crowding, in which objects are too closely packed for attention to single out one of them. This article argues that there is a variant of crowding—what I call ‘‘identity-crowding’’—in which one can consciously see a thing despite failure of attention to it. This conclusion, together with new (...) evidence that attention to an object occurs in unconscious perception, suggests there may be a double dissociation between conscious perception of an object and attention to that object, constraining the extent to which consciousness can be constitutively attentional. The argument appeals to a comparison between the minimal resolution (or ‘‘grain’’) of object-attention and object-seeing. (shrink)

Consciousness is a mongrel concept: there are a number of very different "consciousnesses." Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of "consciousness" based on (...) the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct "guesses," but they cannot harness this information in the service of action, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are BOTH access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness. (shrink)

The role of contingent contexts in formulating relations between properties of systems at different descriptive levels is addressed. Based on the distinction between necessary and sufficient conditions for interlevel relations, a comprehensive classification of such relations is proposed, providing a transparent conceptual framework for discussing particular versions of reduction, emergence, and supervenience. One of these versions, contextual emergence, is demonstrated using two physical examples: molecular structure and chirality, and thermal equilibrium and temperature. The concept of stability is emphasized as a (...) basic guiding principle of contextual property emergence. (shrink)

An innocent form of emergence—what I call "weak emergence"—is now a commonplace in a thriving interdisciplinary nexus of scientific activity—sometimes called the "sciences of complexity"—that include connectionist modelling, non-linear dynamics (popularly known as "chaos" theory), and artificial life.1 After defining it, illustrating it in two contexts, and reviewing the available evidence, I conclude that the scientific and philosophical prospects for weak emergence are bright.