Evan Thompson

In this thesis, I show how decisions about the ontology of colour depend upon the empirical and conceptual relations among levels of explanation for vision. In Chapter 1, I show how the "received" Lockean view of colour is linked to Newton's theory of light and colour. In Chapter 2, I review extensively recent biological, psychophysical, and computational models of colour vision, and I discuss their relations. I also show how the ontological status of colour is linked to these levels of explanation for the specific case of colour constancy. This empirical discussion provides the foundation for Chapters 3 and 4 where I argue that both objectivism and subjectivism are untenable on extensive empirical grounds. ;In Chapter 3, I argue that the computational level of explanation is not sufficient to ground an objectivist view of colour. Colour cannot be identified with surface spectral reflectance, nor can our present conception of colour be replaced by a new concept of physical colour as surface reflectance. An adequate account of colour must, then, be experientialist. I conclude this chapter by showing how arguments against objectivism are not sufficient to establish subjectivism. ;In Chapter 4, I present a novel philosophical argument based on the comparative study of colour vision in different species. This body of research has been largely neglected both by philosophers and by those who work on computational colour vision. My "comparative argument" purports to show that an adequate account of colour must be both experientialist and ecological. Whereas computational objectivism runs afoul of the experiential nature of colour, neurophysiological subjectivism runs afoul of the ecological nature of colour experience. In contrast to both objectivism and subjectivism, I defend a new view of colour, which I call ecological experientialism. According to this view, colour corresponds to a type of property that is interactional, i.e., to a type of property that results from the biological and ecological interactions of perceiving and cognizing animals. Therefore, to account for colour we must state generalizations over the ecologically embodied visual experiences of perceiving animals.

The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference , which will also be suitable as an advanced textbook

This paper develops a bridge from AL issues about the symbol–matter relation to AI issues about symbol-grounding by focusing on the concepts of formality and syntactic interpretability. Using the DNA triplet-amino acid specification relation as a paradigm, it is argued that syntactic properties can be grounded as high-level features of the non-syntactic interactions in a physical dynamical system. This argu- ment provides the basis for a rebuttal of John Searle’s recent assertion that syntax is observer-relative (1990, 1992). But the argument as developed also challenges the classic symbol-processing theory of mind against which Searle is arguing, as well as the strong AL thesis that life is realizable in a purely computational medium. Finally, it provides a new line of support for the autonomous systems approach in AL and AI (Varela & Bourgine 1992a, 1992b). © 1997 Academic Press

Could there be genuinely novel colours — that is, visual qualities having a hue that bears a resemblance relation to red, green, yellow, and blue, yet is neither reddish, nor greenish, nor yellowish, nor blueish?1 And if there could be such colours, what would it be like to see them? How would the colours look? In his article,"Epiphenomenal Qualia,"2 Frank Jackson presents a philosophical thought experiment that raises these questions . Jackson asks us to imagine a perceiver named Fred who is like us except that he has the ability to see a hue we cannot see. Jackson's question is: "What is the new colour or colours like?"3 Jackson argues that all the physical information about Fred, including the physiology of his brain and visual system, and his dispositions to behaviour, would not enable us to answer this question. The totality of physical information would still leave out something about Fred's experience, namely, what the extra hue is like from the subjective perspective of Fred. And if at some point we became able to see this extra hue , we would learn something that we did not know as a result of having all the physical information about Fred: We would learn how the extra hue looks and thereby learn just what it was that made Fred's experience different from ours. Jackson calls his argument "the knowledge argument." In his view, the argument is similar to Thomas Nagel's in his article "What is it Like to Be a Bat?,"4 but both its point and ultimate conclusion are different. Nagel argues that facts about what conscious experience is like for some creature are essentially connected to the subjective perspective of the creature. The problem that Nagel poses is, how could such facts be revealed in anything objective and physical about the creature? How could the objective characterization indicate what it is like to be the creature ? The point of Jackson's argument, however, is not that we would not know what it is like to be Fred even if we knew everything physical about him ; it is rather that there is still something we do not know about Fred's experience — a property that it has — even when we have all the physical information about him: We do not know how the extra hue that Fred sees looks to Fred, and so we do not know all that there is to know about how Fred's experience of seeing the extra hue differs from his experience of seeing red, green, yellow, and blue.5 Jackson's conclusion is also stronger than Nagel's.

Contributors to the latest Canadian Journal of Philosophy Supplementary Volume, _The Problem of Consciousness_, make connections regarding what is consciousness and how it is related to the natural world. The essays in this volume address this question from the perspective of phenomenological philosophy of mind, a new trend that integrates phenomenology, analytic philosophy, and cognitive science. The guiding principle of this new thinking is that precise and detailed phenomenological accounts of subjective experience are needed if significant progress is to be made in understanding consciousness and its place in the natural world. From this standpoint, the essays collected here explore a variety of nuances concerning consciousness, including time consciousness, perception, schizophrenia, empathy, and intersubjectivity. Also addressed are fascinating methodological issues about the relationship between phenomenology and other approaches to understanding the mind in science and philosophy

It is now conventional wisdom that conscious experience — or in Nagel’s canonical characterization, “what it is like to be” for an organism — is what makes the mind-body problem so intractable. By the same token, our current conceptions of the mind-body relation are inadequate and some conceptual development is urgently needed. Our overall aim in this paper is to make some progress towards that conceptual development. We first examine a currently neglected, yet fundamental aspect of consciousness. This aspect is the spontaneity of consciousness, by which we mean its inner plasticity and inner purposiveness. We then sketch a “neurophenomenological” framework for thinking about the relationship between the spontaneity of consciousness and dynamic patterns of brain activity as studied in cognitive neuroscience. We conclude by proposing that the conscious mentality of sentient organisms or animals is active and dynamic, and that this “enactive” conception of consciousness can help us to move beyond the classical dichotomy between materialism and dualism

Buddhism originated and developed in an Indian cultural context that featured many first-person practices for producing and exploring states of consciousness through the systematic training of attention. In contrast, the dominant methods of investigating the mind in Western cognitive science have emphasized third-person observation of the brain and behavior. In this chapter, we explore how these two different projects might prove mutually beneficial. We lay the groundwork for a cross-cultural cognitive science by using one traditional Buddhist model of the mind – that of the five aggregates – as a lens for examining contemporary cognitive science conceptions of consciousness.

Suppose that a team of neurosurgeons and bioengineers were able to remove your brain from your body, suspend it in a life-sustaining vat of liquid nutrients, and connect its neurons and nerve terminals by wires to a supercomputer that would stimulate it with electrical impulses exactly like those it normally receives when embodied. According to this brain-in-a-vat thought experiment, your envatted brain and your embodied brain would have subjectively indistinguishable mental lives. For all you know—so one argument goes—you could be such a brain in a vat right now.1 Daniel Dennett calls this sort of philosophical thought experiment an “intuition pump” (Dennett 1995). An intuition pump is designed to elicit certain intuitive convictions, but is not itself a proper argument: “intuition pumps are fine if they’re used correctly, but they can also be misused. They’re not arguments, they’re stories. Instead of having a conclusion, they pump an intuition. They get you to say ‘Aha! Oh, I get it!’ (Dennett 1995, p. 182). Philosophers have used the brain-in-a-vat story mainly to raise the problem of radical skepticism and to elicit various intuitions about meaning and knowledge (Putnam 1981). The basic intuition the story tries to pump is that the envatted brain, though fully conscious, has systematically false beliefs about the world, including itself. Some philosophers reject this intuition. They propose that the envatted brain’s beliefs are really about its artificial environment or that it..

• An adequate conceptual framework is still needed to account for phenomena that (i) have a first-person, subjective-experiential or phenomenal character; (ii) are (usually) reportable and describable (in humans); and (iii) are neurobiologically realized.2 • The conscious subject plays an unavoidable epistemological role in characterizing the explanadum of consciousness through first-person descriptive reports. The experimentalist is then able to link first-person data and third-person data. Yet the generation of first-person data raises difficult epistemological issues about the relation of second-order awareness or meta-awareness to first-order experience (e.g.

We argue that the minimal biological requirements for consciousness include a living body, not just neuronal processes in the skull. Our argument proceeds by reconsidering the brain-in-a-vat thought experiment. Careful examination of this thought experiment indicates that the null hypothesis is that any adequately functional “vat” would be a surrogate body, that is, that the so-called vat would be no vat at all, but rather an embodied agent in the world. Thus, what the thought experiment actually shows is that the brain and body are so deeply entangled, structurally and dynamically, that they are explanatorily inseparable. Such entanglement implies that we cannot understand consciousness by considering only the activity of neurons apart from the body, and hence we have good explanatory grounds for supposing that the minimal realizing system for consciousness includes the body and not just the brain. In this way, we put the brain-in-a-vat thought experiment to a new use, one that supports the “enactive” view that consciousness is a life-regulation process of the whole organism interacting with its environment.