Philosophy and the Neurosciences

Philosophy and the Neurosciences is probably best described as an introduction to the philosophy of the neurosciences, for a reader who is already somewhat familiar with either the contemporary philosophy of mind or the neurosciences (preferably both). It is edited, and to a significant part also written, by William Bechtel as well as Pete Mandik, Jennifer Mundale and Robert Stufflebeam, three of his former students at the Philosophy-Neuroscience-Psychology graduate program at Washington University.

The book has six parts, including “Neurophilosophical Foundations,” “Language,” “Vision,” “Consciousness,” “Representation,” and “Reduction.” Each part contains a brief one to two page introduction, on average four articles on each topic, and a list of questions for further reflection on the material. The introductions give a brief, accessible overview over the main issues that will be discussed in each part; the list of study questions usually refers very closely to the material presented in the articles. The articles are a well-balanced combination of “classic” papers, less well known, but instructive previously published articles, and original contributions mostly by the editors. The book is structured in a way that is intended to enable the reader to engage with the material and find their way through the different positions and problems, without assuming too much initial familiarity with the material. For the reader who is new to the field, it provides an introduction to methods and basic problems in neuroscience and philosophy, several helpful historical overviews and frequent cross-references.

Part 1, “Neurophilosophical Foundations” delivers largely what it promises, as far as this is possible in no more than 80 pages. Bechtel, Mandik, and Mundale prepare the stage by characterizing briefly what the neurosciences are, then introducing basic issues from the philosophy of science and mind, and finally giving an overview over specific philosophical issues concerning the neurosciences. Daugman’s article puts the currently dominant metaphors about the mind in perspective by presenting a history of popular models of the mind, ranging from embodied spirits to computers. Mundale gives a brief history of the neuron doctrine and the question of localization of mental function, and by the same token manages to introduce those readers who may need this information to basic brain anatomy. Bechtel and Stufflebeam then describe the available methods for gathering data about the working of the brain and discuss the assumptions that are made in interpreting such data. They specifically discuss, at some length, problems with regard to brain imaging. As an exemplary case they discuss work on language by Petersen, who is then himself represented in the next part.

The second part, “Language,” covers mostly two issues, namely the questions of localization and modularity of language. It starts with two classic papers by Broca and Wernecke on aphasia, which are illustrative of their respective methodological approaches. The paper by Petersen and Fiez gives an overview over some of their PET studies on the processing of single words. At the same time, it is also an example for the methods of localization in brain imaging, and illustrates nicely some of the problems that had been previously pointed out by Bechtel and Stufflebeam. Bates then discusses critically the popular issue of the modularity of language and argues that assuming innateness and localization of language does not imply that it is actually modular. Bechtel’s paper attempts to draw these different issues together. He sketches which philosophical issues are at stake here, discusses the respective role of different disciplines for research into language, and mentions some additional data that may indicate that further changes in the understanding of the issues of localization and modularity could be required.

The third part, “Vision,” is the part of the book that is most strongly neurophysiological in character. It starts with a paper by Hubel and Wiesel in which they report their groundbreaking research into the structure and function of the primary visual cortex. The next paper by Mishkin, Ungerleider and Macko describes the results of their work on the visual system beyond the primary visual cortex, which was the basis for their claim that there are two different pathways of visual information processing, one dedicated to object vision (the ventral pathway), the other to spatial vision (the dorsal pathway). Van Essen and Gallant elaborate further on the issue of separate processing pathways and give a now far more differentiated picture of the complex structure, connections and functions in the visual cortex. Again, Bechtel’s paper addresses the philosophical significance of the neuroscientific data. He sketches the history of research into the visual system, which he regards as “exemplar for Cognitive Neuroscience”, and ends by arguing for the value of a Marr-style project for the computational analysis of vision.

Part 4, on “Consciousness”, does not engage too extensively with the standard debates in the philosophy of mind. It engages neither in full-blown qualia-mania nor qualia-bashing. Instead, it offers a somewhat mixed bag of issues and approaches (and seems to me to be the overall weakest part of the book). It begins with a 1998 article by Crick and Koch, where the issue of binding is given less prominence than previously. Using experimental data, e.g. on binocular rivalry, they now postulate a specific role of the highest levels of visual processing and of the prefrontal cortex for visual consciousness. Prinz then criticizes this hypothesis and argues that focus on mechanisms of attention may yield more promising results. In the second (not too clearly related) part of his paper he takes on Block’s arguments against functionalism and Kripke’s against materialism. Hardcastle’s paper on pain introduces the neurophysiology of pain and points out that philosophers have underestimated the complexity of the phenomenon of pain. Finally, Mandik argues for understanding the subjective character of experience in terms of perspectival representations, without the usual recourse to indexicality. (It was actually a bit surprising to see this paper not in the section on representations, especially given its explicit references to Bechtel and Akins.)

Part 5, on “Representations”, takes on the controversial issue of how representations relate both to the world and to neurophysiological processes. Bechtel proposes a minimal notion of representation as information-bearing state, and claims that this notion can be shown to possibly underlie representations that seem to have more demanding characteristics. Grush, in contrast, proposes that it is not just the informational content that makes a representation what it is, but its use in the emulation of action. Akins argues against the claim that for understanding representation it is particularly helpful to look at sensory systems. On the basis of the case of thermoreceptors, she claims that at least some sensory systems are “narcissistic” instead of representational. Stufflebeam makes the case for a restrictive understanding of representation.

Part 6, “Reduction”, is the shortest part of the book (I found it actually somewhat surprising that this important issue was dealt with in less space and using less authors than the other issues in the book). It features an exchange between the Churchlands and McCauley. While the Churchlands argue for the possibility of intertheoretic reduction between the neurosciences and psychology, McCauley holds that intertheoretic reduction between different levels of abstraction is generally not an option, because they usually have different and equally legitimate explanatory aims. He claims that the Churchlands themselves at times seem to hold as much; however, in their reply they give a number of examples that make clear that they regard intertheoretic reduction as a possible, frequently occurring and desirable case.

Overall, Philosophy and the Neurosciences promises to be a very valuable textbook for anybody interested in the relation between neuroscience for philosophy. Most of the book is as clearly structured and accessibly written as seems possible in this field. I am, however, not sure just how much knowledge of both disciplines is necessary to benefit most from it – I doubt that just an introductory class to the philosophy of mind or to the workings of the brain will do it, but I may be mistaken.

One of the few things one may find missing is the explicit concern with the issues of affect and action. It is not too difficult to think of reasons for such an omission, but it is at least insofar remarkable as there has been a strongly increasing interest in these topics in philosophy as well as the neurosciences in the past years. As it is, the selection reflects in some sense a traditional understanding of what kinds of questions the philosophy of mind and science need to be concerned about. In any case, even with this restriction, Philosophy and the Neurosciences already includes a broad range of fascinating issues.

© 2002 Heike Schmidt-Felzmann. First serial rights

Heike Schmidt-Felzmann holds graduate degrees in philosophy and psychology from the University of Hamburg, Germany. She is currently a doctoral candidate in philosophy and works on ethics in psychotherapy.