ON CONSCIOUSNESS the book by Ted Honderich reviewed by Paavo Pylkkanen There is a range of convincing arguments to do with the impossibility of explaining consciousness within the framework of orthodox neuroscience. While some criticise these arguments and hope to account for consciousness in terms of conventional science, others explore more exotic alternatives such as panprotopsychism, quantum consciousness, antirealism or dual aspect theory. In On Consciousness, philosopher Ted Honderich introduces yet another exotic view, which he calls 'Radical Externalism' or 'Consciousness as Existence'. Honderich acknowledges the fact of psychoneural intimacy: conscious or mental events are in some kind of necessary connection with neural events. This intimacy has often been taken as a sign of identity, leading to mind-brain identity theories which claim that conscious events are neural ones. However, for Honderich and many others consciousness doesn't seem to be that sort of physical thing. They feel that mind-brain identity theories leave out something essential, namely the reality of our mental lives, the most immediate of all the facts we know. One option for the identity theorist is to admit that it is not possible to reduce consciousness to neural processes as conceived by contemporary neuroscience, but to argue that consciousness consists in some as yet unknown physical process, which future neuroscience may be able to describe. Honderich rejects this option as 'much too strange and adventurous'. He thinks that conscious events are more than neural, but is unwilling to account for this by postulating any new feature of the world. Thus the non-neural properties of consciousness must somehow be explained in terms of concepts we already possess. But how? He suggests that the key challenge is to find a different way of thinking about familiar ideas. There is what we already know to be inside our heads (the stuff that neuroscience describes) and what is outside our heads (the subject matter of both perceptual experience and science). Because it seems obvious to Honderich that consciousness has features that don't belong  inside heads, he is left with only one option, namely to locate the non-neural properties of consciousness outside our heads. And this has to be done without adding anything outrageous to the ontology we already have. The outcome of reasoning within these constraints is what he calls 'Radical Extemalism' or 'Consciousness as Existence'. The starting point of Honderich's new theory is the proposal 'my perceptual consciousness now consists in the existence of a world'. But what does 'world' mean here? He notes that in everyday usage 'world' is a unitary concept However there are secondary usages involving three worlds that are relatively inde-pendent of minds or subjects -- i.e. the 'physical world' which is spatio-temporal and has perceived properties or is spatio-temporal and is in nomic (i.e. lawlike) connection with things that have perceived properties; the 'objective world' which has in it things perceivable by more than one person and also exists independently of perception; finally, there is the 'world of things in current and anticipated science'. But Honderich recommends that an adequate account of consciousness requires yet another conception of world. This is the world that is             ' my perceptual consciousness. His theory relies on understanding relations between these several conceptions, especially those involving his newly proposed world.                                                      - The difference between 'my world of perceptual consciousness' and the mind-independent worlds consists in the former depending on me and my neural events. Further, it is private and does not exist unperceived. However there is also a large similarity between the world of perceptual consciousness and the perceived part of the physical world. Both are spatial, temporal and contain objects like chairs. A further similarity is that both depend upon neural events and upon yet another world, 'the worid-in-itself'. The similarity between the world of perceptual consciousness and the perceived part of the physical world is crucially important for Honderich's theory, for it suggests that 'my world of perceptual consciousness' is a world 'out there' and cannot be regarded as simply an inner mental world of thoughts and feelings. In somewhat Berkeleyan fashion, Honderich states that worlds of perceptual consciousness are the only worlds that are not theoretical. The idea, in a nutshell, is that for something to be conscious is for a world to exist. Thus Honderich's is a view of perceptual consciousness as existence, or of existence as perceptual consciousness Honderich's strategy is to contemplate consciousness directly. For him the fundamental issue about consciousness is its seeming mystery With his reconceptualization he hopes to shed light on it. believing that trying to dissipate the mystery is better than recoiling from it. This attitude makes his book stand out from the vast current literature on consciousness. There would never have been a quantum theory if physicists had not appreciated the mysteriousness of certain experimental results, and gone on to seek for new ideas to explain them Analogously, I think there will never be a theory of consciousness if researchers do not first appreciate and acknowledge how very puzzling it is. Indeed, there is no need for a theory if there is nothing to explain! In this respect Honderich is on the right track. Unlike many of his physicalist colleagues, he does not sweep the . mystery of consciousness under the carpet. It is right there throughout, and its presence gives much force and beauty to the book. However, one can also wonder about Honderich's strategy, especially his view that no new empirical discoveries are needed to account for consciousness. If this were so, it would be unlike almost anything hitherto encountered by the natural sciences. For if one looks at the history of science one can frequently see how new entities and processes have been proposed to account for puzzling phenomena, and how later developments have either confirmed or questioned the existence of such entities. Atomic theory is perhaps the most strikingly successful example of such a proposal. So I doubt whether Honderich is correct in this respect. I suspect that a deeper understanding of the physiology of the brain (e.g. one using the rich conceptual and empirical resources of quantum physics) is likely to significantly increase our understanding of the relation of matter with consciousness. However, this need not undermine the value of Honderich's approach, for any putative new 'quantum approach' to consciousness would need to answer the profound questions that he so elegantly poses. It is not likely that neuroscience, even when enriched by some deeper theory, could directly tackle the mystery of consciousness. It needs to be complemented with a more philosophical theory, and here Honderich's view could play a key role. So I agree that reconceptualizing what we already know, in the way Honderich proposes, may be a strategy crucial to understanding consciousness. But reconceptualization of the old and search for the new should surely go hand in hand, mutually constraining and complementing each other as we strive toward a better theory. In conclusion, I think Honderich's approach both new and very interesting. It deserves the attention of both those who view conscious experience as deeply puzzling and those who see no mystery. The review appeared in The Journal of Consciousness Studies, 12, 7, 2005. Prof. Pylkkanen is at the University of Skovde and is an editor of Dimensions of Conscious Experience (Blackwell) and Bohm-Biederman Correspondence: Creativity and Science (Books Haat). There is also another review of On Consciousness to which  you can turn -- Professor Barbara  Hannan's. For much more discussion of this theory of consciousness, go to Radical Externalism: Honderich's Theory of Consciousness Discussed. HOME to T.H. website front page HOME to Det & Free front page