James C. Blackmon

I argue that if minds supervene on the intrinsic physical properties of things like brains, then typical human brains host many minds at once. Support comes from science-nonfiction realities that, unlike split-brain cases, have received little direct attention from philosophers. One of these realities is that some patients are functioning (albeit impaired) and phenomenally conscious by all medical and commonsense accounts despite the fact that they have undergone a hemispherectomy: an entire brain hemisphere has been fully detached. Another is the Wada test, in which a patient has each hemisphere anesthetized, one after the other, while the other hemisphere is awake and functioning—again, phenomenally conscious by any standard. I will argue that hemispherectomies, Wada tests, and related procedures each present cases in which the minds that exist after the detachment (or anesthetization) of a hemisphere are surviving minds which must be associated with the surviving (or un-anesthetized) hemisphere. I will argue that such surviving minds existed before the medical procedure, instantiated by the then-intact hemisphere that was due to survive the loss of its complementary hemisphere. If so, then the typical subject has at least three minds: a “left hemisphere mind”, a “right hemisphere mind”, and a “whole brain mind”. But the argument generalizes to cases in which smaller portions of the brain are lost, yielding a great number of additional minds, some overlapping. Some important ethical implications are raised and briefly examined.

A ghost is a supernatural being that is typically described as capable of appearing to, speaking to, and even doing harm to a person. But it is also described as a being that you cannot touch or affect in the usual ways. Lots of things seem weird at first, but humans don't think of them as supernatural. It's easy to see how material things interact with each other. After all, they are, by their very essence as things filling space, things that cannot merge into each other. Descartes' view is not just a philosophical speculation; it is also a scientific hypothesis. Although Descartes' reasons for dualism are based primarily in deep philosophical meditation, his reason for identifying the pineal gland as the seat of the soul is based in his investigation of the human brain where Descartes finds an anatomical explanation for some obvious facts about human perception.

The current debate over systematicity concerns the formal conditions a scheme of mental representation must satisfy in order to explain the systematicity of thought.1 The systematicity of thought is assumed to be a pervasive property of minds, and can be characterized (roughly) as follows: anyone who can think T can think systematic variants of T, where the systematic variants of T are found by permuting T’s constituents. So, for example, it is an alleged fact that anyone who can think the thought that John loves Mary can think the thought that Mary loves John, where the latter thought is a systematic variant of the former.

The current debate over systematicity concerns the formal conditions a scheme of mental representation must satisfy in order to explain the systematicity of thought.1 The systematicity of thought is assumed to be a pervasive property of minds, and can be characterized (roughly) as follows: anyone who can think T can think systematic variants of T, where the systematic variants of T are found by permuting T’s constituents. So, for example, it is an alleged fact that anyone who can think the thought that John loves Mary can think the thought that Mary loves John, where the latter thought is a systematic variant of the former

In this paper, we introduce a novel difficulty for teleosemantics, viz., its inability to account for what we call unexploited content—content a representation has, but which the system that harbors it is currently unable to exploit. In section two, we give a characterization of teleosemantics. Since our critique does not depend on any special details that distinguish the variations in the literature, the characterization is broad, brief and abstract. In section three, we explain what we mean by unexploited content, and argue that any theory of content adequate to ground representationalist theories in cognitive science must allow for it.1 In section four, we show that teleosemantic theories of the sort we identify in section two cannot accommodate unexploited content, and are therefore unacceptable if intended as attempts to ground representationalist cognitive science. Finally, in section five, we speculate that the existence and importance of unexploited content has likely been obscured by a failure to distinguish representation from indication, and by a tendency to think of representation as reference.

In addition to his famous Chinese Room argument, John Searle has posed a more radical problem for views on which minds can be understood as programs. Even his wall, he claims, implements the WordStar program according to the standard definition of implementation because there is some ‘‘pattern of molecule movements’’ that is isomorphic to the formal structure of WordStar. Program implementation, Searle charges, is merely observer-relative and thus not an intrinsic feature of the world. I argue, first, that analogous charges involving other concepts (motion and meaning) lead to consequences no one accepts. Second, I show that Searle’s treatment of computation is incoherent, yielding the consequence that nothing computes anything: even our standard personal computers fail to run any programs on this account. I propose an alternative account, one that accords with the way engineers, programmers, and cognitive scientists use the concept of computation in their empirical work. This alternative interpretation provides the basis of a philosophical analysis of program implementation, one that may yet be suitable for a computational theory of the mind.

Integrated Information Theory (IIT) identifies consciousness with having a maximum amount of integrated information. But a thing’s having the maximum amount of anything cannot be intrinsic to it, for that depends on how that thing compares to certain other things. IIT’s consciousness, then, is not intrinsic. A mereological argument elaborates this consequence: IIT implies that one physical system can be conscious while a physical duplicate of it is not conscious. Thus, by a common and reasonable conception of intrinsicality, IIT’s consciousness is not intrinsic. It is then argued that to avoid the implication that consciousness is not intrinsic, IIT must abandon its Exclusion Postulate, which prohibits overlapping conscious systems. Indeed, theories of consciousness that attribute consciousness to physical systems, should embrace the view that some conscious systems overlap. A discussion of the admittedly counterintuitive nature of this solution, along with some medical and neuroscientific realities that would seem to support it, is included.