The Conscious Brain brings neuroscientific evidence to bear on enduring philosophical questions. Major philosophical and scientific theories of consciousness are surveyed, challenged, and extended.

Conscious experience is one of the most difficult and thorny problems in psychological science. Its study has been neglected for many years, either because it was thought to be too difficult, or because the relevant evidence was thought to be poor. Bernard Baars suggests a way to specify empirical constraints on a theory of consciousness by contrasting well-established conscious phenomena - such as stimulus representations known to be attended, perceptual, and informative - with closely comparable unconscious ones - such as (...) stimulus representations known to be preperceptual, unattended, or habituated. Adducing data to show that consciousness is associated with a kind of global workplace in the nervous system, and that several brain structures are known to behave in accordance with his theory, Baars helps to clarify many difficult problems. (shrink)

In this paper I discuss three problems of consciousness. The first two have been dubbed the “Hard Problem” and the “Harder Problem”. The third problem has received less attention and I will call it the “Hardest Problem”. The Hard Problem is a metaphysical and explanatory problem concerning the nature of conscious states. The Harder Problem is epistemological, and it concerns whether we can know, given physicalism, whether some creature physically different from us is conscious. The Hardest Problem is a problem (...) about reference. Recently some philosophers – among them David Papineau – who advocate a physicalist approach to both the Hard and the Harder problem have called into question the common sense assumption that phenomenal concepts – subjective concepts that we apply directly to experience – refer determinately (modulo vagueness) to real properties that can be instantiated in minds other than my own. The Hardest Problem is the problem of explaining how, given physicalism, this assumption could be true. In this paper I explore how these three problems appear from the perspective of a physicalist approach to consciousness based on Brian Loar’s account of phenomenal concepts, recently dubbed the “phenomenal concept strategy”. My contention is that this approach can go quite far in handling not just the first two problems but the Hardest Problem as well. (shrink)

Claims about consciousness in animals are often made in support of their moral standing. Peter Carruthers argues that there is no fact of the matter about animal consciousness and it is of no scientific or ethical significance. Sympathy for an animal can be grounded in its mental states, but should not rely on assumptions about its consciousness.

This book explores a neglected philosophical question: How do groups of interacting minds relate to singular minds? Could several of us, by organizing ourselves the right way, constitute a single conscious mind that contains our minds as parts? And could each of us have been, all along, a group of mental parts in close cooperation? Scientific progress seems to be slowly revealing that all the different physical objects around us are, at root, just a matter of the right parts put (...) together in the right ways: How far could the same be true of minds? This book argues that we are too used to seeing the mind as an indivisible unity and that understanding our place in nature requires being willing to see minds as composite systems, simultaneously one conscious whole and many conscious parts. In thinking through the implications of such a shift of perspective, the book relates the question of mental combination to a range of different theories of the mind (in particular panpsychism, functionalism, and Neo-Lockeanism about personal identity) and identifies, clarifies, and addresses a wide array of philosophical objections (concerning personal identity, the unity of consciousness, the privacy of experience, and other issues) that have been raised against the idea of composite minds. The result is an account of the metaphysics of composition and consciousness that can illuminate many different debates in philosophy of mind, concerning split brains, collective intentionality, and the combination problem, among others. (shrink)

Studies causation both as a concept and as it is 'in the objects.' Offers new accounts of the logic of singular causal statements, the form of causal regularities, the detection of causal relationships, the asymmetry of cause and effect, and necessary connection, and it relates causation to functional and statistical laws and to teleology.

More than twenty years after its original publication, _The Case for Animal Rights _is an acknowledged classic of moral philosophy, and its author is recognized as the intellectual leader of the animal rights movement. In a new and fully considered preface, Regan responds to his critics and defends the book's revolutionary position.

Sometimes it is indeterminate what an agent morally ought do. This generates a Decision Ought Challenge—to give moral guidance to agents in such a scenario. This article is a field guide to the options for a theory of the decision ought for cases of indeterminacy. Three categories of view are evaluated, and the best representative for each is identified.

Introduction -- A default position -- Experience -- The character of experience -- Understanding-experience -- A note about dispositional mental states -- Purely experiential content -- An account of four seconds of thought -- Questions -- The mental and the nonmental -- The mental and the publicly observable -- The mental and the behavioral -- Neobehaviorism and reductionism -- Naturalism in the philosophy of mind -- Conclusion: The three questions -- Agnostic materialism, part 1 -- Monism -- The linguistic argument (...) -- Materialism and monism -- A comment on reduction -- The impossibility of an objective phenomenology -- Asymmetry and reduction -- Equal-status monism -- Panpsychism -- The inescapability of metaphysics -- Agnostic materialism, part 2 -- Ignorance -- Sensory spaces -- Experience, explanation, and theoretical integration -- The hard part of the mind-body problem -- Neutral monism and agnostic monism -- A comment on eliminativism, instrumentalism, and so on -- Mentalism, idealism, and immaterialism -- Mentalism -- Strict or pure process idealism -- Active-principle idealism -- Stuff idealism -- Immaterialism -- The positions restated -- The dualist options -- Frege's thesis -- Objections to pure process idealism -- The problem of mental dispositions -- Mental -- Shared abilities -- The sorting ability -- The definition of mental being -- Mental phenomena -- The view that all mental phenomena are experiential phenomena -- Natural intentionality -- E/c intentionality -- The experienceless -- Intentionality and abstract and nonexistent objects -- Experience, purely experiential content, and n/c intentionality -- Concepts in nature -- Intentionality and experience -- Summary with problem -- Pain and pain -- The neo-behaviorist view -- A linguistic argument for the necessary connection between pain and behavior -- A challenge -- The Sirians -- N.N. Novel -- An objection to the Sirians -- The Betelgeuzians -- The point of the Sirians -- Functionalism, naturalism, and realism about pain -- Unpleasantness and qualitative character -- The weather watchers -- The rooting story -- What is it like to be a weather watcher? -- The aptitudes of mental states -- The argument from the conditions for possessing the concept of space -- The argument from the conditions for language ability -- The argument from the nature of desire -- Desire and affect -- The argument from the phenomenology of desire -- Behavior -- A hopeless definition -- Difficulties -- Other-observability -- Neo-behaviorism -- The concept of mind. (shrink)

A phenomenal concept is the concept of a particular type of sensory or perceptual experience, where the notion of experience is understood phenomenologically. A recent and increasingly influential idea in philosophy of mind suggests that reflection on these concepts will play a major role in the debate about conscious experience, and in particular in the defense of physicalism, the thesis that psychological truths supervene on physical truths. According to this idea—I call it the phenomenal concept strategy —phenomenal concepts are importantly (...) different from other concepts, and arguments against physicalism fatally neglect to take this difference into account. This paper divides the phenomenal concept strategy into a number of different versions, and argues that no version of the strategy is successful. The paper ends by contrasting the phenomenal concept strategy with a rival strategy—I call it the missing concept strategy . I suggest that the missing concept strategy presents a more plausible response to the issues about physicalism and experience. (shrink)

Since its original publication in 1975, this groundbreaking work has awakened millions of concerned men and women to the shocking abuse of animals everywhere--inspiring a worldwide movement to eliminate much of the cruel and unnecessary laboratory animal experimentation of years past. In this newly revised and expanded edition, author Peter Singer exposes the chilling realities of today's "factory farms" and product-testing procedures--offering sound, humane solutions to what has become a profound environmental and social as well as moral issue. An important (...) and persuasive appeal to conscience, fairness, decency and justice, Animal Liberation is essential reading for the supporter and the skeptic alike.--From publisher description. (shrink)

I argue that there can be no such thing as a borderline case of the predicate ‘phenomenally conscious’: for any given creature at any given time, it cannot be vague whether that creature is phenomenally conscious at that time. I first defend the Positive Characterization Thesis, which says that for any borderline case of any predicate there is a positive characterization of that case that can show any sufficiently competent speaker what makes it a borderline case. I then appeal to (...) the familiar claim that zombies are conceivable, and I argue that this claim entails that there can be no positive characterizations of borderline cases of ‘phenomenally conscious’. By the Positive Characterization Thesis, it follows that ‘phenomenally conscious’ can not have any borderline cases. (shrink)

This is the first of two papers in which we propose an evolutionary route for the transition from sensory processing to unlimited experiencing, or basic consciousness. We argue that although an evolutionary analysis does not provide a formal definition and set of sufficient conditions for consciousness, it can identify crucial factors and suggest what evolutionary changes enabled the transition. We believe that the raw material from which feelings were molded by natural selection was a global sensory state that we call (...) overall sensation, which is a by-product of the incessant activity of the highly interconnected nervous systems that characterize all neural animals. We argue that global sensory states generated limited experiencing once they became coupled to the simplest kinds of nervous-system-mediated learning, a coupling that occurred in the most ancient taxa of neural animals, which were similar to present-day cnidarians and ctenophores. In such animals, limited experiencing involves a small number of persistent global sensory states. These sensory states, however, do not have a function and do not act as motivational states. As we argue in the next paper, with the evolution of associative learning they evolved into systems that gave animals basic consciousness. (shrink)

Most people will grant that we bear special moral obligations toward at least some nonhuman animals that we do not bear toward inanimate objects like stones, mountains, or works of art. These moral obligations are plausibly grounded in the fact that many if not all nonhuman animals share important psychological states and capacities with us, such as consciousness, suffering, and goal-directed behavior. But which of these states and capacities are really critical for a creature’s possessing moral status, and how can (...) we determine which animals do in fact have them? In this paper, I examine three main approaches to answering these questions. First are what I term consciousness-based approaches that tackles these questions by first asking which animals are conscious. Second are affective-state approaches that focus on identifying behavioural and physiological signatures of states like pain, fear, and stress. Finally, I consider what I call preference-based approaches whose focus is on the question of which organisms have robust motivational states. I examine the prospects and challenges—both theoretical and empirical—faced by these seemingly contrasting methodologies. I go on to suggest that there are reasons why, despite challenges, we should be robustly committed to the project of identifying psychological grounds of moral status. I conclude by suggesting we should also take seriously the idea of pluralism about moral status, according to which each of these approaches might be capable of providing independent grounds for moral consideration. (shrink)

Most scientific theories of consciousness are challenging to apply outside the human case insofar as non‐human systems (both biological and artificial) are unlikely to implement human architecture precisely, an issue I call the specificity problem. After providing some background on the theories of consciousness debate, I survey the prospects of four approaches to this problem. I then consider a fifth solution, namely the theory‐light approach proposed by Jonathan Birch. I defend a modified version of this that I term the modest (...) theoretical approach, arguing that it may provide insights into challenging cases that would otherwise be intractable. (shrink)

Block’s well-known distinction between phenomenal consciousness and access consciousness has generated a large philosophical literature about putative conceptual connections between the two. The scientific literature about whether they come apart in any actual cases is rather smaller. Empirical evidence gathered to date has not settled the issue. Some put this down to a fundamental methodological obstacle to the empirical study of the relation between phenomenal consciousness and access consciousness. Block (2007) has drawn attention to the methodological puzzle and attempted to (...) answer it. While the evidence Block points to is relevant and important, this paper puts forward a more systematic framework for addressing the puzzle. To give it a label, the approach is to study phenomenal consciousness as a natural kind. The approach allows consciousness studies to move beyond the initial means of identifying instances of the kind, like verbal report, and to find its underlying nature. It is wellrecognised that facts about an underlying kind may allow identification of instances of the kind that do not match the initial means of identification (cp. non-liquid samples of water). This paper shows that the same method can be deployed to investigate phenomenal consciousness independently of access consciousness. (shrink)

The question “are garden snails conscious?” or equivalently “is there something it’s like to be a garden snail?” admits of three possible answers: yes, no, and denial that the question admits of a yes-or-no answer. All three answers have some antecedent plausibility, prior to the application of theories of consciousness. All three answers retain their plausibility after the application of theories of consciousness. This is because theories of consciousness, when applied to such a different species, are inevitably question-begging and rely (...) crucially on dubious extrapolation from the introspections and verbal reports of a single species. (shrink)

This article defends the existence of _borderline consciousness._ In borderline consciousness, conscious experience is neither determinately present nor determinately absent, but rather somewhere between. The argument in brief is this. In considering what types of systems are conscious, we face a quadrilemma. Either nothing is conscious, or everything is conscious, or there’s a sharp boundary across the apparent continuum between conscious systems and nonconscious ones, or consciousness is a vague property admitting indeterminate cases. Assuming mainstream naturalism about consciousness, we ought (...) to reject the first three options, which forces us to the fourth, indeterminacy. Standard objections to the existence of borderline consciousness turn on the inconceivability of borderline cases. However, borderline cases are only inconceivable by an inappropriately demanding standard of conceivability. I conclude with some plausible cases and applications. (shrink)

Neuroimaging studies of brain-damaged patients diagnosed as in the vegetative state suggest that the patients might be conscious. This might seem to raise no new ethical questions given that in related disputes both sides agree that evidence for consciousness gives strong reason to preserve life. We question this assumption. We clarify the widely held but obscure principle that consciousness is morally significant. It is hard to apply this principle to difficult cases given that philosophers of mind distinguish between a range (...) of notions of consciousness and that is unclear which of these is assumed by the principle. We suggest that the morally relevant notion is that of phenomenal consciousness and then use our analysis to interpret cases of brain damage. We argue that enjoyment of consciousness might actually give stronger moral reasons not to preserve a patient's life and, indeed, that these might be stronger when patients retain significant cognitive function. (shrink)

This precis explains that _Philosophical naturalism contains three parts. Part I examines arguments for physicalism and maintains I) that all causally relevant special science properties must be realized by physical ones, and II) that all special science laws must reduce to physical ones, apart from the significant category of special laws that result from selection processes. Part II defends a teleological theory of representation and an identity theory of consciousness. Part III defends reliabilism and applies it to inductive scepticism and (...) also defends a fictionalist account of mathematics. (shrink)

Opponents to consciousness in fish argue that fish do not feel pain because they do not have a neocortex, which is a necessary condition for feeling pain. A common counter-argument appeals to the multiple realizability of pain: while a neocortex might be necessary for feeling pain in humans, pain might be realized differently in fish. This paper argues, first, that it is impossible to find a criterion allowing us to demarcate between plausible and implausible cases of multiple realization of pain (...) without running into a circular argument. Second, opponents to consciousness in fish cannot be provided with reasons to believe in the multiple realizability of pain. I conclude that the debate on the existence of pain in fish is impossible to settle by relying on the multiple realization argument. (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)

Is consciousness intrinsically valuable? Some theorists favor the positive view, according to which consciousness itself accrues intrinsic value, independent of the particular kind of experience instantiated. In contrast, I favor the neutral view, according to which consciousness is neither intrinsically valuable nor disvaluable. The primary purpose of this paper is to clarify what is at stake when we ask whether consciousness is intrinsically valuable, to carve out the theoretical space, and to evaluate the question rigorously. Along the way, I also (...) show why the neutral view is attractive and why certain arguments for the positive view do not work. (shrink)

The essence of who we are depends on our brains. They enable us to think, to feel joy and sorrow, communicate through speech, reflect on the moments of our lives, and to anticipate, plan for, and worry about our imagined futures. Although some of our abilities are comparatively new, key features of our behavior have deep roots that can be traced to the beginning of life. By following the story of behavior, step-by-step, over its roughly four-billion-year trajectory, we come to (...) understand both how similar we are to all organisms that have ever lived, and how different we are from even our closest animal relatives. We care about our differences because they are ours. But differences do not make us superior; they simply make us different. (shrink)

Illusionists about phenomenal consciousness claim that phenomenal consciousness does not exist but merely seems to exist. At the same time, it is quite intuitive for there to be some kind of link between phenomenality and value. For example, some situations seem good or bad in virtue of the conscious experiences they feature. Illusionist views of phenomenal consciousness then face what I call the normative challenge. They have to say where they stand regarding the idea that there is a link between (...) phenomenality and value. If they accept that there is such a link, they might be committed to revisionary normative consequences (and some of them may prove to be uncomfortable). If they deny that there is such link, they might avoid revisionary normative consequences (without being guaranteed against them) but then they have to give reasons to deny that such link obtains, which is not a trivial task. The existence of the normative challenge does not show that illusionism is false, but it shows that illusionism might have important consequences in the normative domain, which have to be clarified. (shrink)

Neuroimaging studies of brain-damaged patients diagnosed as in the vegetative state suggest that the patients might be conscious. This might seem to raise no new ethical questions given that in related disputes both sides agree that evidence for consciousness gives strong reason to preserve life. We question this assumption. We clarify the widely held but obscure principle that consciousness is morally significant. It is hard to apply this principle to difficult cases given that philosophers of mind distinguish between a range (...) of notions of consciousness and that is unclear which of these is assumed by the principle. We suggest that the morally relevant notion is that of phenomenal consciousness and then use our analysis to interpret cases of brain damage. We argue that enjoyment of consciousness might actually give stronger moral reasons not to preserve a patient's life and, indeed, that these might be stronger when patients retain significant cognitive function. (shrink)

It seems obvious that phenomenally conscious experience is something of great value, and that this value maps onto a range of important ethical issues. For example, claims about the value of life for those in a permanent vegetative state, debates about treatment and study of disorders of consciousness, controversies about end-of-life care for those with advanced dementia, and arguments about the moral status of embryos, fetuses, and non-human animals arguably turn on the moral significance of various facts about consciousness. However, (...) though work has been done on the moral significance of elements of consciousness, such as pain and pleasure, little explicit attention has been devoted to the ethical significance of consciousness. In this book Joshua Shepherd presents a systematic account of the value present within conscious experience. This account emphasizes not only the nature of consciousness, but the importance of items within experience such as affect, valence, and the complex overall shape of particular valuable experiences. Shepherd also relates this account to difficult cases involving non-humans and those with disorders of consciousness, arguing that the value of consciousness influences and partially explains the degree of moral status a being possesses, without fully determining it. The upshot is a deeper understanding of both the moral importance of phenomenal consciousness and its relations to moral status. This book will be of great interest to philosophers and students of ethics, bioethics, philosophy of psychology, philosophy of mind and cognitive science. (shrink)

This paper looks at the phenomenon of ethical vagueness by asking the question, how ought one to reason about what to do when confronted with a case of ethical vagueness? I begin by arguing that we must confront this question, since ethical vagueness is inescapable. I then outline one attractive answer to the question: we ought to maximize expected moral value when confronted with ethical vagueness. This idea yields determinate results for what one rationally ought to do in cases of (...) ethical vagueness. But what it recommends is dependent on which substantive theory of vagueness is true; one can't draw conclusions about how to reason about vagueness in ethics in the absence of concrete assumptions about the nature of vagueness. (shrink)

Amidst the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of those dissenting results. On the basis of a minimal neuro-computational model, the global neuronal workspace hypothesis, we propose a (...) taxonomy which distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with a sudden surge of parieto-frontal activity causing top-down amplification. (shrink)

Valence is a central component of all affective states, including pains, pleasures, emotions, moods, and feelings of desire or repulsion.This paper has two main goals. One is to suggest that enough is now known about the causes, consequences, and properties of valence to indicate that it forms a unitary natural-psychological kind, one that seemingly plays a fundamental role in motivating all kinds of intentional action. If this turns out to be true, then the correct characterization of the nature of valence (...) becomes an urgent philosophical issue. There appear to be just two accounts that have the required generality. According to one, valence is a nonconceptual representation of value. According to the other, valence is an intrinsic qualitative property of experience. The second goal of the paper is to contrast and evaluate these two views of the nature of valence, drawing on the relevant empirical findings. Overall, I suggest that the representational account is more plausible. (shrink)