By Daniel N. Robinson, Maxwell R. Bennett, Daniel C. Dennett, Peter Hacker, John Searle

Publisher: Columbia University Press
ISBN: 9780231140447
£15.95

Maxwell Bennett, a neuroscientist, and Peter Hacker, an analytic philosopher co-authored a book in 2003 entitled Philosophical Foundations of Neuroscience in which they attempted to show there was a great deal of conceptual confusion among neuroscientists that is preventing them from correctly formulating their questions and understanding exactly what their experiments show. This book generated a lively discussion among neuroscientists and philosophers, with some claiming that they undermine neuroscience, and that their approach would limit scientific enquiry too severely. Due to the controversy that they had created Bennett and Hacker met with Daniel Dennett and John Searle at the American Philosophical Association to debate their book. Neuroscience & Philosophy is the record of this debate.

This book begins with ‘The Argument’ which features extracts from Philosophical Foundations of Neuroscience in order to clarify for the reader Bennett and Hacker’s main points. This is followed by ‘The Rebuttals’ which are critical responses from Dennett and Searle. Bennett and Hacker then respond to Dennett and Searle in ‘Reply to Rebuttals’. The volume also includes an introduction and conclusion by Daniel Robinson. The book is very accessible to non-specialists, but it can get technical in places. It will also help introduce readers to various topics in cognitive neuroscience and philosophy of mind such as qualia, consciousness and ordinary language philosophy.

The Argument

Bennett and Hacker regard the division between philosophy and science as being very clear. Philosophy is the study of concepts, whereas science is the study of facts. They claim that science is an attempt to distinguish truth from falsity, whereas philosophy is the attempt to distinguish sense from nonsense. This means that empirical observation cannot be used to settle problems in the philosophy of mind, and confusion concerning the use of concepts in neuroscience will only lead to more confusion. One must first get the concepts in order before any fruitful empirical enquiry can take place. This would not be such a big issue if Bennett and Hacker did not think there was such widespread confusion among neuroscientists.

Their central argument is that many neuroscientists are committing the mereological fallacy; that is, attributing to the part what can only sensibly be attributed to the whole. They list many examples of where neuroscientists describe the brain and parts of the brain as thinking, deciding, knowing, and many other intentional states that they claim can only sensibly be attributed to the person. They argue that this is mistaken in the same way that it would be mistaken to say that “my tennis racket is playing tennis”, or “my hands are playing tennis” rather than “I am playing tennis”. They take this to be the point Wittgenstein was trying to make when he said that “Only of a human being and of what resembles (behaves like) a living human being can one say: it has sensations; it sees, is blind; hears, is deaf; is conscious or unconscious”.

They include many examples of neuroscientists writing in this way, and they also demonstrate how it affects the way they think about the subject and the conclusions they draw. It is not clear that this confusion is a problem from what Bennett and Hacker have said, but they make a convincing argument that neuroscientists have failed to distinguish between the human being, and the brain as a part of a human being. They claim that it is a problem inherited from Rene Descartes. In Cartesian philosophy the mind is a separate substance from the body, and is the location of all thought. Modern neuroscientists have rejected this Cartesian Dualism, claim Bennett and Hacker, but they have simply moved the location of thought from the mind to the brain, creating a kind of brain-body dualism.

Bennett and Hacker claim that this confusion warrants an entire rethink to the way we approach neuroscience, however, others disagree.

The Rebuttals

Daniel Dennett and John Searle are accustomed to being on opposing sides in most debates, so it is a testament to the controversial nature of Bennett and Hacker’s work that they have received responses from both these writers. However, although Dennett and Searle disagree with Bennett and Hacker, they do not agree about the nature of their error.

Dennett responds by agreeing that much of neuroscience has been laid astray by Cartesian Dualism by simply shifting all talk of the mind to the brain. This Dennett calls Cartesian materialism, and he points out that he has spent many years criticising it in his writings. It is when Dennett turns to these areas that the heat involved in this debate becomes apparent.

He has two main objections to Bennett and Hacker. The first is that there is no clear divide between philosophy and science, just as you can be right or wrong in science you can also be right or wrong in philosophy. Philosophy and science are not the same subject, but there is a continuum, according to Dennett, between the conceptual and the empirical which means that scientific discoveries do help us to determine the best use of our concepts.

The second argument is that the brain is relevantly like a human, so that the Wittgensteinian rule permits the extension of terms such as thinking and deciding to the brain. Dennett argues that it is one of the empirical discoveries of neuroscience that the brain engages in activities very like these ones, and so, it is a mark of progress that we are able to extend the language in this way. Dennett claims that Bennett and Hacker’s mereological fallacy simply does not apply in this case, and that without it the argument amounts to very little.

John Searle’s response is very clearly written, and is possibly the most helpful chapter in the book, as he does an excellent job of explaining both what his position is, but also the position taken by Bennett and Hacker. Like Dennett, Searle finds their distinction between philosophy and science to be simplistic and says that he is not convinced by any attempt to demarcate philosophy that he has come across.

Searle’s main argument against Bennett and Hacker is that they fail to distinguish between the rules for ascribing mental states and the criteria for having mental states. He argues that there are three features of mental states that Bennett and Hacker do not account for; they are qualia, the cause of consciousness and the location of consciousness. Bennett and Hacker are describing the linguistic rules that tell us when we are permitted to ascribe mental states to agents. However, just because brains do not exhibit the correct behaviour to have mental states attributed to them it does not mean that they do not play an important role in mental states. Searle argues that mental states are qualia – they have a particular subjective character, that they are caused by the brain and that they are located in the brain. This means that the can have mental states ascribed to it because it is the reason that the person is in a particular mental state.

Reply to Rebuttals

Bennett and Hacker fail to add much to the debate in their reply. It is mainly a reiteration of what they have already said, albeit much more clearly and forcefully.

They object to Dennett’s claim that the brain is sufficiently like a human being that mental states can be ascribed to it in a derivative sense. They maintain that in order to be ascribed with a mental state the agent must exhibit the correct behaviour, but the brain is incapable of this. They object to Searle’s account of the person as being a conscious brain, and instead argue that a person is a human being with observable behaviour, and that is what mental states should be ascribed to.

At the end of this book it is unlikely that anyone will have been convinced by any of the writers, but this book has helped to demonstrate that there is confusion over these issues, no matter what side you take. It is clear that to say a neuron knows something is to say something very different to saying that a human knows something (if the former makes sense at all), the danger in neuroscience is to think that to give an explanation of the former is also to give an explanation of the latter.

This book is a helpful introduction to some important debates in neuroscience and philosophy of mind. It has done a good job of representing the different points of view, which will hopefully serve to move this debate forward. It also demonstrates the importance of interdisciplinary research. This debate started when Bennett, a neuroscientist contacted Hacker, a philosopher, and it seems to have produced some interesting work. Many other subjects would no doubt benefit from similar collaborations.