Commissurotomy surgery has lately attracted considerable philosophical attention. It has seemed to some that the surgical scalpel that bisects the brain bisects consciousness and the mind as well; and that the ordinary concept of a person is thereby most seriously threatened. I shall assess the extent of the threat, arguing that it is overestimated. The argument begins with section III; section II, which describes the operation and its effects, should be omitted by those already familiar with these facts.

Block has attempted to reduce the confusion and controversy concerning the term “consciousness” by suggesting that there are two forms or types of consciousness, each of which has several characteristics or properties. This suggestion appears to further becloud the topic, however. Perhaps consciousness cannot be defined adequately and should not be considered as a topic that can be studied scientifically.

In philosophy, the criteria for personhood (PH) at a specific point in time (synchronic), and the necessary and sufficient conditions of personal identity (PI) over time (diachronic) are traditionally separated. Hence, the transition between both timescales of a person's life remains largely unclear. Personal habits reflect a decision-making (DM) process that binds together synchronic and diachronic timescales. Despite the fact that the actualization of habits takes place synchronically, they presuppose, for the possibility of their generation, time in a diachronic sense. (...) The acquisition of habits therefore rests upon PI over time; that is, the temporal extension of personal decisions is the necessary condition for the possible development of habits. Conceptually, habits can thus be seen as a bridge between synchronic and diachronic timescales of a person's life. In order to investigate the empirical mediation of this temporal linkage, we draw upon the neuronal mechanisms underlying DM; in particular on the distinction between internally and externally guided DM. Externally guided DM relies on external criteria at a specific point in time (synchronic); on a neural level, this has been associated with lateral frontal and parietal brain regions. In contrast, internally guided DM is based on the person's own preferences that involve a more longitudinal and thus diachronic timescale, which has been associated with the brain's intrinsic activity. Habits can be considered to reflect a balance between internally and externally guided DM, which implicates a particular temporal balance between diachronic and synchronic elements, thus linking two different timescales. Based on such evidence, we suggest a habit-based neurophilosophical approach of PH and PI by focusing on the empirically-based linkage between the synchronic and diachronic elements of habits. By doing so, we propose to link together what philosophically has been described and analyzed separately as PH and PI. (shrink)

The human self model comprises essential features such as the experiences of ownership, of body-centered spatial perspectivity, and of a long-term unity of beliefs and attitudes. In the pathophysiology of schizophrenia, it is suggested that clinical subsyndromes like cognitive disorganization and derealization syndromes reflect disorders of this self model. These features are neurobiologically instantiated as an episodically active complex neural activation pattern and can be mapped to the brain, given adequate operationalizations of self model features. In its unique capability of (...) integrating external and internal data, the prefrontal cortex (PFC) appears to be an essential component of the neuronal implementation of the self model. With close connections to other unimodal association cortices and to the limbic system, the PFC provides an internally represented world model and internal milieu data of the organism, both serving world orientation. In the pathophysiology of schizophrenia, it is the dysfunction of the PFC that is suggested to be the neural correlate for the different clinical schizophrenic subsyndromes. The pathophysiological study of psychiatric disorders may contribute to the theoretical debate on the neuronal basis of the self model. (shrink)

Blocks distinction between “phenomenal feel” consciousness and “thought/cognition” consciousness is a cultural construction. Consciousness (and its “subspecies”) is not a natural kind. Some crosscultural data are presented to support this.

1. The current political scene in many countries is populated by polarised groups with sharply contrasting loyalties and beliefs implying that there are fundamental schisms between opposing groups....

It is argued that there is no fallacy in the reasoning in the example of the thirsty blindsight subject, on one reconstruction of that reasoning. Neither the case of orgasm nor the case of a visual versus an auditory experience as of something overheard shows that phenomenal content is not representational.

Traditional scientific views of the conscious self and world we live in are challenged by an unprecedented outburst of emerging new paradigms, theories of consciousness, perceptions of reality, new sciences, new philosophies, epistemologies, and a host of other transformative approaches. This still expanding outburst can be traced, on both logical and chronologic grounds, not to chaos theory, ecology, the new physics, or dozens of other currently ascribed sources, but rather to the cognitive (consciousness) revolution that immediately preceded. These new approaches (...) all share one key feature in common, namely, they all depend, directly or indirectly, upon a refutation and successful overthrow of the long dominant materialist paradigm. This is what was required to shift consciousness from an acausal or "eliminable" status to a functionally indispensable role. Traditional "bottom‐up" micro‐determinism had to be supplemented by a reciprocal, "top‐down" control exerted by mental emergents over lower‐level components. This does not dispose of behaviorism or reductionism, as methodology, but simply incorporates these within a more comprehensive explanatory framework. With the long reign of materialist constraints finally broken, other antireductive views have proliferated but with little regard for what the new paradigm allows. (shrink)

If phenomenal consciousness is distinct from the computationally based access-consciousness that controls overt behavior, how can I tell which things (other than myself) enjoy phenomenal consciousness? And if phenomenal consciousness 'plays no role in controlling overt behavior, how do human bodies come to write target articles arguing for the existence of phenomenal consciousness?

This paper re-evaluates Derek Parfit’s attack on the commonly held view that personal identity is necessarily determinate and that it is what matters. In the first part we first argue against the Humean view of personal identity; secondly, we classify the remaining alternatives into three kinds: the body theory and the brain theory, the quasi-Humean theory, and the soul theory, and thirdly we deploy Parfit’s arguments and related considerations to the point that none of the materialistic alternatives is consistent with (...) the commonly held view. This leaves us with the alternative: either we accept the radical and highly implausible materialistic view Parfit calls ‘Reductionism’, or we accept the view that we are nonphysical indivisible entities—Cartesian egos, or souls. The second part of the paper discusses Parfit’s objections against the Cartesian view: that there is no reason to believe in the existence of such nonphysical entities; that if such entities exist, there is no evidence that they are enduring ; that even if they exist and are enduring, they are irrelevant for the psychological profile and temporal continuity of a person; that experiments with ‘brain-splitted’ patients provide strong evidence against the Cartesian view. We argue that these objections are in part mistaken, and that the remaining part is not strong enough to make the Cartesian view less plausible than Reductionism. (shrink)

: This paper argues for a distinction between possession of a unified consciousness and possession of a single stream of consciousness. Although the distinction has widespread applicability in discussions of the structure of consciousness and of pathologies of conscious experience, I will illustrate its importance primarily using the debate about consciousness in split-brain subjects, suggesting that those who have argued that split-brain subjects have two streams of consciousness apiece and those who have argued that they have a unified consciousness may (...) both be right. (shrink)

Many experimental findings with split-brain subjects intuitively suggest that each such subject has two minds. The conceptual and empirical basis of this duality intuition has never been fully articulated. This article fills that gap, by offering a reconstruction of early neuropsychological literature on the split-brain phenomenon. According to that work, the hemispheres operate independently of each other insofar as they interact via the mediation of effection and transduction—via behavior and sensation, essentially. This is how your mind and my mind interact (...) with each other, however, giving rise to the intuition that a split-brain subject has two minds. (shrink)

The attempt to model the structure of consciousness in split-brain subjects is ongoing. This paper concerns the recently proposed ?switch model? of split-brain consciousness, according to which a split-brain subject possesses only a single stream of consciousness, unified at and across time, that shifts from one hemisphere to the other from moment to moment. The paper argues that while the central explanatory element of the switch model may account for some aspects of split-brain consciousness, the best general picture of split-brain (...) consciousness is still offered by some version of the ?conscious duality model.? (shrink)

It is generally assumed that group agency must be a social phenomenon because it involves interactions among many human beings. This assumption overlooks the real metaphysical nature of agency, which is both normative and voluntarist. Construed as a normative phenomenon, individual agency arises wherever there is a point of view from which deliberation and action proceed in accord with the requirements that define individual rationality. Such a point of view is never a metaphysical given, but is always a product of (...) rational activities that aim to satisfy the requirements that define individual rationality. When such a deliberative point of view is forged within a whole human life, there is a single agent of human size. But such points of view can also be forged within parts of human lives so as to constitute multiple agents within them; and they can also be achieved within groups of human lives so as to constitute group agents that literally deliberate and act as one. If such a group agent were a social phenomenon, then its agency would simultaneously be the agency of many even as it was also the agency of one. In that case, its deliberations and actions would have to proceed from many separate deliberative points of view, at the same time that they also proceeded from a single deliberative point of view. A correct account of rational agency shows that this is not necessarily so, and indeed, not typically so. Moreover, if it were so much as possible for this to be so, it would require special conditions of the sort that Rousseau identified in his account of the general will. But this special case is not a good model on which to understand the cases of group agency that are most often discussed in the philosophical literature. They are more appropriately viewed as cases in which the condition of individual agency is realized at the level of a group, than as cases of social agency per se. (shrink)

It has been claimed that we need singular self-knowledge to function properly as rational agents. I argue that this is not strictly true: agents in certain relations could dispense with singular self-knowledge and instead rely on plural self-knowledge. In defending the possibility of this kind of ‘selfless agent’, I thereby defend the possibility of a certain kind of ‘seamless’ collective agency; agency in a group of agents who have no singular self-knowledge, who do not know which member of the group (...) they are. I discuss four specific functions for which singular self-knowledge has been thought indispensable: distinguishing intentional from unintentional actions, connecting non-indexical knowledge with action, reflecting on our own reasoning, and identifying which ultimate practical reasons we have. I argue in each case that by establishing certain relations between agents – relations I label ‘motor vulnerability’, ‘cognitive vulnerability’, ‘evidential unity’ and ‘moral unity’ – we would allow those agents to do everything a rational agent needs to do while relying only on plural, rather than singular, self-knowledge. Finally, I consider the objection that any agents who met the conditions I lay out for selfless agency would thereby cease to qualify as distinct agents, merging into a single agent without agential parts. Against this objection, I argue that we should recognise the possibility of simultaneous agency in whole and parts, and not regard either as disqualifying the other. (shrink)

Science is full of surprises. Fortunately, most of these surprises are small. A scientist, for example, might make an unexpected discoverey, but the discovery simply adds new data in support of an old theory. Or perhaps the discovery will endanger an existing theory, but one which has only local import. In cases like these, the existing theory will be modified, or perhaps even rejected; but the research tradition which surrounds the local theory will remain, by and large, unaffected and will (...) continue on.Small surprises are welcomed within science; they are part of the daily grist. Science needs them in order to advance in an orderly fashion. (shrink)

Science is full of surprises. Fortunately, most of these surprises are small. A scientist, for example, might make an unexpected discoverey, but the discovery simply adds new data in support of an old theory. Or perhaps the discovery will endanger an existing theory, but one which has only local import. In cases like these, the existing theory will be modified, or perhaps even rejected; but the research tradition which surrounds the local theory will remain, by and large, unaffected and will (...) continue on.Small surprises are welcomed within science; they are part of the daily grist. Science needs them in order to advance in an orderly fashion. (shrink)

Block's P-/A-consciousness distinction rules out P's involving a specific kind of cognitive access and commits him to a “strong” Pconsciousness. This not only confounds plausible research in the area but betrays an anosognosia about Wittgenstein's diagnosis about our philosophical “introspection” of mysterious inner processes.

I criticize Block's examples of P-consciousness and A-consciousness for being flawed and the notion of A-consciousness for not being a notion of consciousness at all. I argue that an empirically important distinction can be made between behavior that is supported by an underlying conscious experience and behavior that is brought about by nonconscious action-control mechanisms. This distinction is different from that made by Block.

In this paper we develop a novel argument against the extended mind hypothesis. Our argument constitutes an advance in the debate, insofar as we employ only premises that are acceptable to a coarse-grained functionalist, and we do not rely on functional disanalogies between putative examples of extended minds and ordinary human beings that are just a matter of fine detail or degree. Thus, we beg no questions against proponents of the extended mind hypothesis. Rather, our argument consists in making use (...) of the following necessary condition on holding a belief for a reason: To believe something for a reason, one must come to believe it in virtue of attitudes that epistemically rationalize the belief that is formed, and one must come to believe in virtue of the fact that these attitudes epistemically rationalize the new belief. We show that many external objects that defenders of the extended mind hypothesis have claimed are beliefs cannot constitute a belief had for a reason, as they necessarily fail to satisfy the necessary condition. Our first thesis, then, is that beliefs had for reasons cannot be extended in the most interesting way specified by the extended mind hypothesis. Furthermore, if we add to our argument the premise that every token belief is something that could have been had for a reason, we can derive the stronger thesis that no beliefs can be extended in this way. (shrink)

There are researchers in cognitive science who use clinical and experimental evidence to draw some rather skeptical conclusions about a central feature of our conscious experience, its unity. They maintain that the examination of clinical phenomena reveals that human consciousness has a much more fragmentary character than the one we normally attribute to it. In the article, these claims are questioned by examining some of the clinical studies on the deficit of anosognosia. I try to show that these studies support (...) a moderate sense of the unity of reflexive consciousness. (shrink)

A-consciousness may be regarded as the visibility of information that is the output of a process within a community of other processes. The most prominent function of “public” dissemination of information is giving access to it to processes whose relevance is not clear at the moment of dissemination. The function of P-consciousness may be outside the realm of cognition.

In response to the objection that his “access-consciousness” is not really consciousness but a matter of the availability of certain information for certain kinds of processing, Block will probably have to argue that consciousness in a more basic, familiar, traditional sense is an essential component of any instance of access-consciousness and thus justifies the name.

In common sense consciousness has a fairly determinate content – the (single) way an experience feels, the (single) line of thought being consciously followed. The determinacy of the object may be achieved by linking Block's two concepts, so that as long as we hold on to the determinacy of content we are unable to separate P and A.

The essay deals with the mechanism of interpretation for legal metaphorical expressions. Firstly, it points out the perspective the cognitive approach induced about legal metaphors; then it suggests that this perspective gains in plausibility when a new bilateral model of language understanding is endorsed. A possible sketch of the meaning-making procedure for legal metaphors, compatible with this new model, is then proposed, and illustrated with some examples built on concepts belonging to the Italian Civil Code. The insights the bilateral model (...) of understanding provides are compared with the practice followed by legal communities for dealing with the metaphorical expressions they coin and use. (shrink)

Many have claimed that split-brain patients are actually two persons. I maintain that both the traditional separation argument and the more recent sophistication argument for the two persons interpretation are inadequate on conceptual grounds. An autonomy argument is inadequate on empirical grounds. Overall, theoretical and practical consequences weigh heavily in favor of adopting a one person interpretation.

Good physical experiments conform to the basic methodological standards of experimental design: they are objective, reliable, and valid. But is this also true of thought experiments? Especially problems of personal identity have engendered hypothetical scenarios that are very distant from the actual world. These imagined situations have been conspicuously ineffective at resolving conflicting intuitions and deciding between the different accounts of personal identity. Using prominent examples from the literature, I argue that this is due to many of these thought experiments (...) not adhering to the methodological standards that guide experimental design in nearly all other disciplines. I also show how empirically unwarranted background assumptions about human physiology render some of the hypothetical scenarios that are employed in the debate about personal identity highly misleading. (shrink)

P/A (Block's phenomenal/access) confounds a logical distinction with an empirical claim. Success of P/A in its logical role has almost no bearing on its plausibility as an empirical thesis (i.e., that two kinds of consciousness exist). The advantage of P/A over a single-consciousness assumption is unclear, but one of Block's analogies for P (liquid in a hydraulic computer) may be used to clarify the notion of consciousness as cognitive “hardware.”.

A prominent view on personal identity over time, Jeff McMahan’s ‘Embodied Mind Account’ (2002) holds that we cease to exist only once our brains can no longer sustain the basic capacity to uphold consciousness. One of the many implications of this view on identity persistence is that we continue to exist throughout even the most severe cases of dementia, until our consciousness irreversibly shuts down. In this paper, I argue that, while the most convincing of prominent accounts of personal identity (...) over time, McMahan’s account faces serious challenges in explanatory power of dementias and related neurodegenerative conditions. Particularly, this becomes visible in the face of emerging methods for neural tissue regeneration, and the possibility of ‘re-emerging patients’. I argue that medical professionals’ neglecting qualitative aspects of identity risks resulting in grave misunderstandings in decision-making processes, and ethically objectionable outcomes in future practices. Finally, I propose revisions which could potentially salvage the great benefits that Embodied Mind Theory still can bring to the field of dementia care in terms of understanding life, death, and identity across the lifespan. (shrink)

Block contends that the concept of consciousness is a mongrel concept and that researchers go astray by conflating different notions of “consciousness.” This is certainly true. In fact, it is truer than Block acknowledges, because his own notion of P-consciousness runs together two, or arguably three, quite different and separable features of a sensory state.

The information processing that constitutes accessconsciousness is not sufficient to make a representational state conscious in any sense. Standard examples of computation without consciousness undermine A-consciousness, and Block's cases seem to derive their plausibility from a lurking phenomenal awareness. That is, people and other minded systems seem to have access-consciousness only insofar as the state accessed is a phenomenal one, or the state resulting from access is phenomenal, or both.

Basically agreeing with Block regarding the need for a distinction between P- and A-consciousness, I characterize the problem somewhat diflerently, relating it more directly to the explanatory gap. I also speculate on the relation between the two forms of consciousness, arguing that some notion of access is essentially involved in phenomenal experience.

This article consists of four parts. In the first part it briefly describes the history of body‐to‐head transplantation (BHT) and the surgical plan proposed by Drs. Sergio Canavero and Ren Xiaoping on a human subject. In the second part it argues that the BHT procedure that they propose is scientifically invalid and technically infeasible so therefore would end in failure. In the third part it argues that the present conceivable procedure of BHT cannot be ethically justified because it would bring (...) great harm to the human subject, it is uncertain who would be the possible beneficiary, and valid informed consent cannot be obtained. In the fourth part it argues that the action of performing the procedure of BHT might violate China’s current criminal and civil laws. The conclusion that follows from the arguments above is that BHT should be prohibited now and also in the near future. However, this conclusion does not preclude scientists, neurosurgeons and bioethicists doing research into scientific, technical, surgical and ethical issues raised by BHT. (shrink)

Block's cases of superblindsight, the pneumatic drill, and the Sperling experiments do not show that P-consciousness and Aconsciousness can come apart. On certain tendentious but not implausible construals of the concepts of P- and A-consciousness, they refer to the same psychological phenomenon.

This commentary offers two criticisms of Block's account of phenomenal consciousness and a brief sketch of a rival account. The negative points are that monitoring consciousness also involves the possession of certain states and that phenomenal consciousness inevitably involves some sort of monitoring. My positive suggestion is that “phenomenal consciousness” may refer to our ability to monitor the rich but preconceptual states that retain perceptual information for complex processing.

One can share Block's aim of distinguishing “phenomenal” experience from cognitive function and agree with much in his views, yet hold that the inclusion of representational content within phenomenal content, if only in certain spatial cases, obscures this distinction. It may also exclude some modular theories, although it is interestingly suggestive of what may be the limits of the phenomenal penetration of the representational mind.